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Articoli di riviste sul tema "Cyclopropane"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 14 dicembre 2024

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1

Craig, Alexander J., e Bill C. Hawkins. "The Bonding and Reactivity of α-Carbonyl Cyclopropanes". Synthesis 52, n. 01 (1 ottobre 2019): 27–39. http://dx.doi.org/10.1055/s-0039-1690695.

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The cyclopropane functionality has been exploited in a myriad of settings that range from total synthesis and methodological chemistry, to medical and materials science. While it has been seen in such a breadth of settings, the typical view of the cyclopropane moiety is that its reactivity is derived primarily from the release of ring strain. While this simplified view is a useful shorthand, it ignores the specific nature of cyclopropyl molecular orbitals. This review aims to present the different facets of cyclopropane bonding by examining the main models that have been used to explain the reactivity of the functionality over the years. However, even with advanced theory, being able to precisely predict the reactivity of an exact system is nigh impossible. Specifically chosen, carbonyl-bearing cyclopropyl species act as so-called acceptor cyclopropanes and, if correctly derivatised, donor–acceptor cyclopropanes. By undertaking a case study of the history of carbonyl cyclopropanes in organic synthesis, this review highlights the relationship between the understanding of theory and pattern recognition in developing new synthetic methods and showcases those successful in balancing this critical junction.1 Cyclopropanes2 The Strain Model3 The Forster–Coulsin–Moffit Model4 The Walsh Model5 Acceptor, Donor, and Donor–Acceptor Cyclopropanes6 Reactions of Carbonyl Cyclopropanes

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2

Dent, BR, B. Halton e AMF Smith. "Synthesis and Trapping of Some Reactive Cyclopropenes". Australian Journal of Chemistry 39, n. 10 (1986): 1621. http://dx.doi.org/10.1071/ch9861621.

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Commencing with 1,1,2-tribromo-2-trimethylsilylcyclopropane (1d), 1,2- dibromo -and 1-bromo-2-trimethylsilyl-cyclopropene (2d) and (6) are easily prepared. These reactive cyclopropenes decompose on standing at ambient temperature but can be trapped in situ as Diels-Alder adducts (4) and (5). Furthermore, 1,2-bis( trimethylsilyl )- and 1- trimethylsilyl-cyclopropene (8) and (9) can be prepared from cyclopropane (1d) via the bromo - and lithio-trimethylsilylcyclopropenes (6) and (7) in a 'one-pot' procedure and trapped as adducts (4e,f) respectively.

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3

Gemoets, J. P., M. Bravo, C. E. McKenna, G. J. Leigh e B. E. Smith. "Reduction of cyclopropene by NifV- and wild-type nitrogenases from Klebsiella pneumoniae". Biochemical Journal 258, n. 2 (1 marzo 1989): 487–91. http://dx.doi.org/10.1042/bj2580487.

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The nitrogenase from wild-type Klebsiella pneumoniae reduces cyclopropene to cyclopropane and propene in the ratio 1:2 at pH 7.5. We show in this paper that the nitrogenase from a nifV mutant of K. pneumoniae also reduces cyclopropene to cyclopropane and propene, but the ratio of products is now 1:1.4. However, both nitrogenases exhibit the same Km for cyclopropene (2.1 x 10(4) +/- 0.2 x 10(4) Pa), considerably more than the Km for the analogous reaction with Azotobacter vinelandii nitrogenase under the same conditions (5.1 x 10(3) Pa). Analysis of the data shows that the different product ratio arises from the slower production of propene compared with cyclopropane by the mutant nitrogenase. During turnover, both nitrogenases use a large proportion of the electron flux for H2 production. CO inhibits the reduction of cyclopropene by both K. pneumoniae proteins, but the mutant nitrogenase exhibits 50% inhibition at approx. 10 Pa, whereas the corresponding value for the wild-type nitrogenase is approx. 110 Pa. However, H2 evolution by the mutant enzyme is much less affected than is cyclopropene reduction. CO inhibition of cyclopropene reduction by the nitrogenases coincides with a relative increase in H2 evolution, so that in the wild-type (but not the mutant) the electron flux is approximately maintained. The cyclopropane/propene production ratios are little affected by the presence of CO within the pressure ranges studied at least up to 50% inhibition.

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4

Kohout, Ladislav. "The synthesis of 5,6-cyclopropanocholestanes with oxygen functions in positions 3 and 7". Collection of Czechoslovak Chemical Communications 51, n. 2 (1986): 429–35. http://dx.doi.org/10.1135/cccc19860429.

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The Simmons-Smith methylenation of the double bond in 3β-acetoxycholest-5-en-7-ols takes place selectively under formation of an adduct the configuration of which is determined by the configuration of the 7-hydroxyl group: 7β-alcohol IV gave 5β,6β-cyclopropane derivative VI, 7α-alcohol V gave 5α,6α-cyclopropane derivative VIII. On photochemically initiated cyclization of 3β-acetoxy-B-homo-5-en-7a-one (XIII) we obtained the product with an α-cyclopropane ring exclusively, i.e. 3β-acetoxy-5,6α-cyclopropano-5α-cholestan-7-one (XII).

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5

Ben Hamadi, Naoufel, e Ahlem Guesmi. "Synthesis of New Spiro-Cyclopropanes Prepared by Non-Stabilized Diazoalkane Exhibiting an Extremely High Insecticidal Activity". Molecules 27, n. 8 (12 aprile 2022): 2470. http://dx.doi.org/10.3390/molecules27082470.

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The synthesis of new insecticidal gem-dimethyspiro-cyclopropanes derived from pyrrolidine-2,3-dione have been described, and their biological effect against different insect species has been evaluated. The presented results demonstrate the excellent insecticidal activity of cyclopropane 5c against Aedes aegypti and Musca domestica. Cyclopropane 5c showed the quickest knockdown and the best killing against Aedes aegypti and Musca domestica compared to trans-chrysanthemic acid and pyrethrin. The biological results of the high insecticidal activity were confirmed by the results of docking. This is evident in the binding affinity obtained for cyclopropane 5c, indicating good binding with an important active amino acid residue of the 5FT3 protein.

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6

Singh, Satya Prakash, e Pompozhi Protasis Thankachan. "Hydroboration of Substituted Cyclopropane: A Density Functional Theory Study". Advances in Chemistry 2014 (18 agosto 2014): 1–7. http://dx.doi.org/10.1155/2014/427396.

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The hydroboration of substituted cyclopropanes has been investigated using the B3LYP density functional method employing 6-31G** basis set. Borane moiety approaching the cyclopropane ring has been reported. It is shown that the reaction proceeds via a three-centered, “loose” and “tight,” transition states when boron added to the cyclopropane across a bond to a substituents. Single point calculations at higher levels of theory were also performed at the geometries optimized at the B3LYP level, but only slight changes in the barriers were observed. Structural parameters for the transition state are also reported.

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7

Trudeau, Stéphane, e Pierre Deslongchamps. "Novel synthesis of a highly functionalized cyclopropane derivative". Canadian Journal of Chemistry 81, n. 9 (1 settembre 2003): 1003–11. http://dx.doi.org/10.1139/v03-119.

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A model study was carried out to explore the feasibility of synthesizing fused tricyclic ring structures containing a C7C8 double bond juncture (steroid numbering) by employing an SN2' cyclization of a silyl enol ether to displace an allylic acetate as the key step. Instead of the anticipated product, highly functionalized cyclopropanes were obtained. These novel cyclopropane structures are the result of the concomitant 1,2-migration of a dithiane thioether moiety and the eventual displacement of the acetate group, followed by the cyclization of the silyl enol ether.Key words: tricycles, SN2' cyclization, inductive effect, cyclopropane.

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8

Fadeev, Alexander A., Alexey O. Chagarovskiy, Anton S. Makarov, Irina I. Levina, Olga A. Ivanova, Maxim G. Uchuskin e Igor V. Trushkov. "Synthesis of (Het)aryl 2-(2-hydroxyaryl)cyclopropyl Ketones". Molecules 25, n. 23 (5 dicembre 2020): 5748. http://dx.doi.org/10.3390/molecules25235748.

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A simple general method for the synthesis of 1-acyl-2-(ortho-hydroxyaryl)cyclopropanes, which belong to the donor–acceptor cyclopropane family, has been developed. This method, based on the Corey–Chaykovsky cyclopropanation of 2-hydroxychalcones, allows for the preparation of a large diversity of hydroxy-substituted cyclopropanes, which can serve as promising building blocks for the synthesis of various bioactive compounds.

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9

Ramnauth, Jailall, e Edward Lee-Ruff. "Photodecarbonylation of chiral cyclobutanones". Canadian Journal of Chemistry 75, n. 5 (1 maggio 1997): 518–22. http://dx.doi.org/10.1139/v97-060.

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Triplet photosensitized irradiation of 2(S),3(R)-bis[(benzoyloxy)methyl]cyclobutanone gave optically pure (−)E-1(S),2(S)-bis(benzoyloxymethyl)cyclopropane as a major product in the nonpolar fraction along with its stereoisomer and cycloelimination products. The absolute stereochemistry of the chiral cyclopropane was established by independent synthesis and X-ray crystal structure determination of a synthetic precursor. The distribution of decarbonylation and cycloelimination products was inversely dependent on the concentration of the substrate. Irradiation of the same ketone in tetrahydrofuran or benzene gave mostly cycloelimination products. Addition of Michler's ketone increased the ratio of photodecarbonylation, suggesting a triplet state pathway for this process. This was corroborated by the addition of dicyanoethylene, which showed significant quenching of photodecarbonylation. Irradiation of 2(S)-[(benzoyloxy)methyl]cyclobutane in acetone gave the corresponding cyclopropane as the principal product. Keywords: photodecarbonylation, chiral cyclopropanes, cyclobutanones, triplet sensitization.

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10

Finta, Zoltán, Zoltán Hell, Agnieszka Cwik e László Tőke. "A Simple Synthesis of 1,1,2-tris-(Hydroxymethyl)-Cyclopropane and Its Dihalo Derivatives". Journal of Chemical Research 2002, n. 9 (settembre 2002): 459–60. http://dx.doi.org/10.3184/030823402103172653.

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The phase transfer catalytic cyclopropanation of the malonic ester of allylic alcohol or its 3,3-dibromo and 3,3-dichloro derivatives yields bicyclic cyclopropane carboxylic acid lactones; reduction of these lactones with LiAlH4 in boiling THF yields the appropriate 1,1,2-tris-(hydroxymethyl)cyclopropanes in satisfactory yield.

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11

Rademacher, Paul. "Photoelectron Spectra of Cyclopropane and Cyclopropene Compounds". Chemical Reviews 103, n. 4 (aprile 2003): 933–76. http://dx.doi.org/10.1021/cr0100143.

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12

Hassenrück, Jessica, e Valentin Wittmann. "Cyclopropene derivatives of aminosugars for metabolic glycoengineering". Beilstein Journal of Organic Chemistry 15 (4 marzo 2019): 584–601. http://dx.doi.org/10.3762/bjoc.15.54.

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Cyclopropenes have been proven valuable chemical reporter groups for metabolic glycoengineering (MGE). They readily react with tetrazines in an inverse electron-demand Diels–Alder (DAinv) reaction, a prime example of a bioorthogonal ligation reaction, allowing their visualization in biological systems. Here, we present a comparative study of six cyclopropene-modified hexosamine derivatives and their suitability for MGE. Three mannosamine derivatives in which the cyclopropene moiety is attached to the sugar by either an amide or a carbamate linkage and that differ by the presence or absence of a stabilizing methyl group at the double bond have been examined. We determined their DAinv reaction kinetics and their labeling intensities after metabolic incorporation. To determine the efficiencies by which the derivatives are metabolized to sialic acids, we synthesized and investigated the corresponding cyclopropane derivatives because cyclopropenes are not stable under the analysis conditions. From these experiments, it became obvious that N-(cycloprop-2-en-1-ylcarbonyl)-modified (Cp-modified) mannosamine has the highest metabolic acceptance. However, carbamate-linked N-(2-methylcycloprop-2-en-1-ylmethyloxycarbonyl)-modified (Cyoc-modified) mannosamine despite its lower metabolic acceptance results in the same cell-surface labeling intensity due to its superior reactivity in the DAinv reaction. Based on the high incorporation efficiency of the Cp derivative we synthesized and investigated two new Cp-modified glucosamine and galactosamine derivatives. Both compounds lead to comparable, distinct cell-surface staining after MGE. We further found that the amide-linked Cp-modified glucosamine derivative but not the Cyoc-modified glucosamine is metabolically converted to the corresponding sialic acid.

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13

Simaan, Marwan, e Ilan Marek. "Diastereo- and enantioselective preparation of cyclopropanol derivatives". Beilstein Journal of Organic Chemistry 15 (21 marzo 2019): 752–60. http://dx.doi.org/10.3762/bjoc.15.71.

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The diastereoselective carbocupration reaction of alkoxy-functionalized cyclopropene derivatives, followed by a subsequent trapping of the resulting cyclopropylmetal species with an electrophilic source of oxygen (oxenoid) afforded various tetrasubstituted cyclopropanol derivatives in high diastereo- and enantiomeric ratios. Similarly, the enantioselective copper-catalyzed carbomagnesiation/oxidation (or amination) sequence on achiral nonfunctionalized cyclopropenes provided the desired cyclopropanol (and cyclopropylamine) derivatives in excellent diastereo- and enantiomeric excesses.

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14

Matyas, Libor, Radek Pohl e Alexander Kasal. "Neighboring Group Participation in 12,20-Dioxopregnanes". Natural Product Communications 2, n. 11 (novembre 2007): 1934578X0700201. http://dx.doi.org/10.1177/1934578x0700201108.

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12,20-Dioxo-5α-pregnan-3β-yl acetate, obtained from hecogenin, was treated with NaH in DMSO to yield the bridged cyclopropano ketone, 3β-hydroxy-12α,21-cyclo-12β,21-methano-5α,17α-pregnan-20-one. In tert-BuOH the reaction leads to 3β-hydroxy-12,21-cyclo-5α-pregn-12,21-en-20-one. Experimental data prove that the new methylene group of the cyclopropane ring came from DMSO.

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15

Song, Xixi, Junbiao Chang, Yuanyuan Zhu, Shuang Zhao e Minli Zhang. "Diastereoselective Synthesis of Spirobarbiturate-Cyclopropanes through Organobase-Mediated Spirocyclopropanation of Barbiturate-Based Olefins with Benzyl Chlorides". Synthesis 51, n. 04 (6 novembre 2018): 899–906. http://dx.doi.org/10.1055/s-0037-1609637.

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The organobase-mediated diastereoselective spirocyclopropanation of barbiturate-based olefins with 2,4-disubstituted benzyl chlorides has been developed. The reactions were carried out efficiently to afford the desired spirobarbiturate-cyclopropanes in up to 95% yield with more than 20:1 dr in favor of anti-isomers. In order to extend synthetic utility of the spiro-products, a Lewis acid induced cyclopropane-ring-expansion isomerization was also demonstrated.

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16

Aleksandrova, Anastasiia M., Alona S. Cherednichenko e Yuliya V. Rassukana. "The Synthesis of Functionalized Dimethylphosphinoyl Cyclopropanes and Cyclobutanes". Journal of Organic and Pharmaceutical Chemistry 21, n. 4 (10 dicembre 2023): 36–42. http://dx.doi.org/10.24959/ophcj.23.299237.

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A simple preparative approach to a series of functionalized dimethylphosphinoyl-containing cyclopropanes and cyclobutanes has been developed; it is based on cyclocondensation of dimethylphosphinoyl acetonitrile with 1,2- and 1,3-dibromoalkanes. Synthetic procedures for obtaining nitriles, amines and carboxylic acids containing in their structure small saturated cyclic rings of cyclopropane or cyclobutane and a dimethylphosphine oxide fragment, which are popular in drug design, have been developed.

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17

Wanapun, D., K. A. Van Gorp, N. J. Mosey, M. A. Kerr e T. K. Woo. "The mechanism of 1,3-dipolar cycloaddition reactions of cyclopropanes and nitrones A theoretical study". Canadian Journal of Chemistry 83, n. 10 (1 ottobre 2005): 1752–67. http://dx.doi.org/10.1139/v05-182.

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The 1,3-dipolar cycloaddition reaction of cyclopropanes and nitrones to give tetrahydro-1,2-oxazine has been studied with density functional theory calculations at the B3LYP/6-31+G(d,p) level of theory. Realistic substituents were modelled including those at the 2-, 3-, 4-, and 6-positions of the final oxazine ring product. The strained σ bond of the cyclopropane was found to play the role of an alkene in a conventional [3+2] dipolar cycloaddition. Two distinct, but similar, reaction mechanisms were found an asymmetric concerted pathway and a stepwise zwitterionic pathway. The reaction barriers of the two pathways were nearly identical, differing by less than ~1 kcal/mol, no matter what the substituents were. The effect of a Lewis acid catalyst was examined and found to have a very large effect on the calculated barriers through coordination to the carbonyl oxygen atoms of the diester substituents on the cyclopropane. The reaction barrier was found to decrease by as much as ~19 kcal/mol when using a BF3 molecule as a model for the Lewis acid catalyst. Solvent effects and the nature of the regiospecificity of the reaction were also examined. Trends in the calculated barriers for the reaction were in good agreement with available trends in the reaction rates measured experimentally. Key words: 1,3-dipolar cycloaddition, cyclopropane, nitrone, tetrahydro-1,2-oxazines, ab initio quantum chemistry, mechanism.

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18

Babu, Kaki Raveendra, Xin He e Silong Xu. "Lewis Base Catalysis Based on Homoconjugate Addition: Rearrangement of Electron-Deficient Cyclopropanes and Their Derivatives". Synlett 31, n. 02 (20 novembre 2019): 117–24. http://dx.doi.org/10.1055/s-0039-1690753.

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Cyclopropane is one of the most reactive functionalities owing to its intrinsic ring strain. Transition-metal catalysis and Lewis acid catalysis have been extensively used in ring openings of cyclopropanes; however, Lewis base-catalyzed activation of cyclopropanes remains largely unexplored. Upon nucleophilic attack with Lewis bases, cyclopropanes undergo ring cleavage in a manner known as homoconjugate addition to form zwitterionic intermediates, which have significant potential for reaction development but have garnered little attention. Here, we present a brief overview of this area, with an emphasis on our recent efforts on Lewis base-catalyzed rearrangement reactions of electron-deficient cyclopropanes using the homoconjugate addition process.1 Introduction2 DABCO-Catalyzed Cloke–Wilson Rearrangement of Cyclopropyl Ketones3 Hydroxylamine-Mediated Tandem Cloke–Wilson/Boulton–Katritzky Reaction of Cyclopropyl Ketones4 Phosphine-Catalyzed Rearrangement of Vinylcyclopropyl Ketones To Form Cycloheptenones5 Phosphine-Catalyzed Rearrangement of Alkylidenecyclopropyl Ketones To Form Polysubstituted Furans and Dienones6 Conclusion and Outlook

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19

Miranda, Margarida S., Darío J. R. Duarte, Joaquim C. G. Esteves da Silva e Joel F. Liebman. "Protonated heterocyclic derivatives of cyclopropane and cyclopropanone: classical species, alternate sites, and ring fragmentation". Canadian Journal of Chemistry 93, n. 7 (luglio 2015): 708–14. http://dx.doi.org/10.1139/cjc-2015-0029.

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A computational study has been performed for protonated oxygen- or nitrogen-containing heterocyclic derivatives of cyclopropane and cyclopropanone. We have searched for the most stable conformations of the protonated species using density functional theory with the B3LYP functional and the 6-31G(2df,p) basis set. More accurate enthalpy values were obtained from G4 calculations. Proton affinities and gas-phase basicities were accordingly derived.

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20

Mlostoń, Grzegorz, Mateusz Kowalczyk, André U. Augustin, Peter G. Jones e Daniel B. Werz. "Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes". Beilstein Journal of Organic Chemistry 16 (10 giugno 2020): 1288–95. http://dx.doi.org/10.3762/bjoc.16.109.

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Ferrocenyl thioketones reacted with donor–acceptor cyclopropanes in dichloromethane at room temperature in the presence of catalytic amounts of Sc(OTf)3 yielding tetrahydrothiophene derivatives, products of formal [3 + 2]-cycloaddition reactions, in moderate to high yields. In all studied cases, dimethyl 2-arylcyclopropane dicarboxylates reacted with the corresponding aryl ferrocenyl thioketones in a completely diastereoselective manner to form single products in which (C-2)-Ar and (C-5)-ferrocenyl groups were oriented in a cis-fashion. In contrast, the same cyclopropanes underwent reaction with alkyl ferrocenyl thioketones to form nearly equal amounts of both diastereoisomeric tetrahydrothiophenes. A low selectivity was also observed in the reaction of a 2-phthalimide-derived cyclopropane with ferrocenyl phenyl thioketone.

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21

Ledingham, Edward, Christopher Merritt, Christopher Sumby, Michelle Taylor e Ben Greatrex. "Stereoselective Cyclopropanation of (–)-Levoglucosenone Derivatives Using Sulfonium and Sulfoxonium Ylides". Synthesis 49, n. 12 (17 marzo 2017): 2652–62. http://dx.doi.org/10.1055/s-0036-1588971.

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The synthesis of tri- and tetrasubstituted cyclopropanes from 3-aryl-substituted levoglucosenones (LGO) has been developed. In contrast to the unstabilised ylide dimethylsulfonium methylide which gives epoxides from LGO via 1,2-addition, we have found that the soft nucleophile dimethylsulfoxonium methylide affords cyclopropanes in moderate yields from LGO and in excellent yields and stereoselectivity with 3-aryl LGO derivatives. The use of 1,1,3,3-tetramethylguanidine as base in DMSO to generate the ylide provided the best yields and shortest reaction times. Ester stabilised sulfonium ylides could also be used to generate tetrasubstituted cyclopropane derivatives. One of the products was converted into a cyclopropyl lactone via Baeyer–Villiger oxidation to demonstrate the utility of applying cyclopropanation chemistry to LGO.

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22

Ivanova, Olga, Vladimir Andronov, Irina Levina, Alexey Chagarovskiy, Leonid Voskressensky e Igor Trushkov. "Convenient Synthesis of Functionalized Cyclopropa[c]coumarin-1a-carboxylates". Molecules 24, n. 1 (24 dicembre 2018): 57. http://dx.doi.org/10.3390/molecules24010057.

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A simple method has been developed for the synthesis of cyclopropa[c]coumarins, which belong to the donor-acceptor cyclopropane family and, therefore, are promising substrates for the preparation of chromene-based fine chemicals. The method, based on the acetic acid-induced intramolecular transesterification of 2-arylcyclopropane-1,1-dicarboxylates, was found to be efficient for substrates containing hydroxy group directly attached to the aromatic ring.

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23

Vereshchagin, Anatolii N., Michail N. Elinson, Nikita O. Stepanov e Gennady I. Nikishin. "New Way to Substitute Tetracyanocyclopropanes: One-Pot Cascade Assembling of Carbonyls and Malononitrile by the Only Bromine Direct Action". ISRN Organic Chemistry 2011 (26 luglio 2011): 1–5. http://dx.doi.org/10.5402/2011/469453.

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The new type of the chemical cascade reaction was found: formation of cyclopropanes from carbonyl compounds and CH acid by the only bromine direct action. The action of aqueous bromine on the carbonyl compounds and malononitrile in EtOH-H2O solutions in the presence of NaOAc results in the formation of 3-substituted 1,1,2,2-tetracyanocyclopropanes in 48–93% yields. The latter are well-known precursors for the different bicyclic heterosystems, among them those containing cyclopropane ring and those possessing different types of pharmacological activity.

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24

Fang, Zeguo, Nawaf Al-Maharik, Peer Kirsch, Matthias Bremer, Alexandra M. Z. Slawin e David O’Hagan. "Synthesis of organic liquid crystals containing selectively fluorinated cyclopropanes". Beilstein Journal of Organic Chemistry 16 (14 aprile 2020): 674–80. http://dx.doi.org/10.3762/bjoc.16.65.

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This paper describes the synthesis of a series of organic liquid crystals (LCs) containing selectively fluorinated cyclopropanes at their termini. The syntheses used difluorocarbene additions to olefin precursors, an approach which proved straightforward such that these liquid crystal candidates could be efficiently prepared. Their physical and thermodynamic properties were evaluated and depending on individual structures, they either displayed positive or negative dielectric anisotropy. The study gives some guidance into effective structure–property relationships for the design of LCs containing selectively fluorinated cyclopropane motifs.

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25

Zhang, Junliang, e Yuanjing Xiao. "ChemInform Abstract: Cyclization of Cyclopropane- or Cyclopropene-Containing Compounds". ChemInform 41, n. 38 (26 agosto 2010): no. http://dx.doi.org/10.1002/chin.201038242.

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26

Denson, J. S. "Cyclopropane". International Anesthesiology Clinics 36, n. 4 (1998): 61–82. http://dx.doi.org/10.1097/00004311-199803640-00008.

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27

Lamberty, J. M. "Cyclopropane". Anaesthesia 42, n. 2 (febbraio 1987): 212–13. http://dx.doi.org/10.1111/j.1365-2044.1987.tb03011.x.

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Ball, C., e R. N. Westhorpe. "Cyclopropane". Anaesthesia and Intensive Care 34, n. 6 (dicembre 2006): 701. http://dx.doi.org/10.1177/0310057x0603400621.

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29

Boichenko, Maksim A., Andrey Yu Plodukhin, Vitaly V. Shorokhov, Danyla S. Lebedev, Anastasya V. Filippova, Sergey S. Zhokhov, Elena A. Tarasenko, Victor B. Rybakov, Igor V. Trushkov e Olga A. Ivanova. "Synthesis of 1,5-Substituted Pyrrolidin-2-ones from Donor–Acceptor Cyclopropanes and Anilines/Benzylamines". Molecules 27, n. 23 (2 dicembre 2022): 8468. http://dx.doi.org/10.3390/molecules27238468.

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We developed a straightforward synthetic route to pharmacologically important 1,5-substituted pyrrolidin-2-ones from donor–acceptor cyclopropanes bearing an ester group as one of the acceptor substituents. This method includes a Lewis acid-catalyzed opening of the donor–acceptor cyclopropane with primary amines (anilines, benzylamines, etc.) to γ-amino esters, followed by in situ lactamization and dealkoxycarbonylation. The reaction has a broad scope of applicability; a variety of substituted anilines, benzylamines, and other primary amines as well as a wide range of donor–acceptor cyclopropanes bearing (hetero)aromatic or alkenyl donor groups and various acceptor substituents can be involved in this transformation. In this process, donor–acceptor cyclopropanes react as 1,4-C,C-dielectrophiles, and amines react as 1,1-dinucleophiles. The resulting di- and trisubstituted pyrrolidin-2-ones can be also used in subsequent chemistry to obtain various nitrogen-containing polycyclic compounds of interest to medicinal chemistry and pharmacology, such as benz[g]indolizidine derivatives.

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30

Mato, Mauro, Inmaculada Martín-Torres, Bart Herlé e Antonio M. Echavarren. "Cyclopropane–alkene metathesis by gold(i)-catalyzed decarbenation of persistent cyclopropanes". Organic & Biomolecular Chemistry 17, n. 17 (2019): 4216–19. http://dx.doi.org/10.1039/c9ob00359b.

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31

Gavrus, Delia. "Envisioning Cyclopropane: Scientific Product or Medical Technology?" Scientia Canadensis 33, n. 1 (3 febbraio 2011): 3–28. http://dx.doi.org/10.7202/1000843ar.

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Abstract (sommario):

In the late 1920s, V.E. Henderson and his team at the University of Toronto discovered the anaesthetic properties of cyclopropane. For a number of reasons, Henderson did not envision cyclopropane as a useful technology: to him it was simply a gas that possessed anaesthetic properties, rather than a potential clinical product, and this explains why cyclopropane was not first introduced into Toronto hospitals. In contrast, the practicing anaesthesiologist Ralph M. Waters envisioned cyclopropane as a medical technology, partly because it could assist his effort to professionalize anaesthesiology in the 1930s. This paper argues that it is useful to make a historically-informed distinction between cyclopropane the experimental laboratory gas and cyclopropane the medical anaesthetic because such a distinction highlights the social dimensions of the process of scientific discovery and helps illuminate the relationship between scientific production and medical technology.

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32

Don Lawson, Chioma, Max Maza-Iglesias, Muthana Sirhan, Jumaa Al Dulayymi e Mark Baird. "The Synthesis of Single Enantiomers of α-Mycolic Acids of Mycobacterium tuberculosis and Related Organisms, with Alternative Cyclopropane Stereochemistries". SynOpen 01, n. 01 (marzo 2017): 0103–16. http://dx.doi.org/10.1055/s-0036-1588556.

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Abstract (sommario):

We report the synthesis of three stereoisomers of a mycolic acid from Mycobacterium tuberculosis containing a di-cis-cyclopropane and of two stereoisomers of a mycolic acid containing a proximal trans-cyclopropane and a distal cis-cyclopropane.

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33

Mead, Keith, e Yahaira Reyes. "Acetoxy-Substituted Cyclopropane Dicarbonyls as Stable Donor–Acceptor–Acceptor Cyclopropanes". Synthesis 47, n. 19 (25 giugno 2015): 3020–26. http://dx.doi.org/10.1055/s-0034-1379934.

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34

Ben Hamadi, Naoufel, Ahlem Guesmi e Wided Nouira. "Asymmetric one-pot synthesis of cyclopropanes". Macedonian Journal of Chemistry and Chemical Engineering 35, n. 1 (18 aprile 2016): 45. http://dx.doi.org/10.20450/mjcce.2016.835.

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Abstract (sommario):

Cycloaddition of the diazoalkanes to electron-deficient olefins (in situ) affords polysubstituted cyclopropanes in high yields (up to 85%). Deprotection of the ketal protecting group provided water-soluble cyclopropane-bearing carbohydrate in good yields. Antimicrobial activity screening of the synthesized compounds 8 and 9, utilizing a variety of Gram-positive (Staphylococcus aureus and Enterococcus fecalis), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and yeast (Candida albicans), exhibited that all the prepared analogues acquire promising activities against both Gram-positive and Gram-negative bacteria especially compounds 9b and 9c (antimicrobial active agents against Gram-negative bacteria).

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35

Herraiz, Ana G., e Marcos G. Suero. "New Alkene Cyclopropanation Reactions Enabled by Photoredox Catalysis via Radical Carbenoids". Synthesis 51, n. 14 (11 giugno 2019): 2821–28. http://dx.doi.org/10.1055/s-0037-1611872.

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Abstract (sommario):

We describe the recent emergence of a new approach for the synthesis of cyclopropane rings by means of photoredox catalysis. This methodology relies on the photocatalytic generation of radical carbenoids or carbenoid-like radicals as cyclopropanating species, and is characterized by excellent functional group tolerance, chemoselectivity and the ability to form cyclopropanes with excellent control from E/Z alkene mixtures. The mild reaction conditions and employment of user-friendly reagents are highly attractive features that may lead to this approach being used in academic and industrial laboratories.1 Introduction2 Photoredox-Catalyzed Alkene Cyclopropanations with Radical Carbenoids3 Conclusions and Outlook

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36

Altamore, Timothy M., Oanh T. K. Nguyen, Quentin I. Churches, Kate Cavanagh, Xuan T. T. Nguyen, Sandhya A. M. Duggan, Guy Y. Krippner e Peter J. Duggan. "Concise Synthesis of Enantiomerically Pure (1'S,2'R)- and (1'R,2'S)-2S-Amino-3-(2'-aminomethyl-cyclopropyl)propionic Acid: Two E-Diastereoisomers of 4,5-Methano-L-lysine". Australian Journal of Chemistry 66, n. 9 (2013): 1105. http://dx.doi.org/10.1071/ch13309.

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Abstract (sommario):

A concise synthesis of both E-isomers of 2S-amino-3-(2′-aminomethyl-cyclopropyl)propionic acid, new methano-l-lysines, is described. The synthetic route includes nine steps from l-methionine, with a key step involving the cyclopropanation of an intermediate E-allylic alcohol. The resultant hydroxymethylcyclopropanes were readily separated and converted into the title α-amino acids. The stereochemistry around the cyclopropane rings was deduced by conducting the cyclopropanation in the presence of N,N,N′,N′-tetramethyl-d-tartaric acid diamide butylboronate, a chiral controller which is known to favour the production of S-hydroxymethyl cyclopropanes from allylic alcohols.

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37

Bilera, Igor V. "The Formation of Small Amounts of Cyclopropane during Pulsed Pyrolysis of C4–C5 Acyclic Alkanes in the Adiabatic Compression Reactor". Reactions 4, n. 3 (19 luglio 2023): 381–97. http://dx.doi.org/10.3390/reactions4030023.

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Abstract (sommario):

During high-temperature pulse pyrolysis of acyclic butanes and pentanes under adiabatic compression conditions, cyclopropane, a stressed cyclic hydrocarbon, was found among the reaction products in small quantities for the first time. The analysis of the reaction products was performed by gas chromatography using three capillary columns of different polarity, selectivity and sufficient efficiency. The identification of reaction products, including cyclopropane, was performed using retention times of individual substances and model mixtures, as well as comparing chromatograms with reference chromatograms from the literature and the ScanView Application Database. It was shown that the chromatographic peak attributed to cyclopropane could not be a ghost peak. Additional confirmation of this conclusion was obtained in a series of experiments on the pyrolysis of n-butane at a reduced initial temperature of the adiabatic compression reactor (from 120 °C to 50 °C) and a modified mode of GC analysis. Cyclopropane yields as a function of maximum temperature have a bell-shaped asymmetric dependence. The maximum value of the yield of cyclopropane increases with the transition from normal alkanes to isoalkanes, and from pentanes to butanes; for n-pentane, 0.009 wt. %, and for isobutene, ≈0.017 wt. %. During the pulse pyrolysis of isobutane, n-butane, isopentane and n-pentane, cyclopropane is not a primary product. Further theoretical and experimental studies are needed to establish the mechanism of cyclopropane formation during pyrolysis of C4–C5 acyclic alkanes.

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38

Zhuo, Chun-Xiang, e Jia-Le Wang. "Catalytic Deoxygenative Cyclopropanation of 1,2-Dicarbonyl or Monocarbonyl Compounds via Molybdenum Catalysis". Synlett 33, n. 07 (13 novembre 2021): 599–608. http://dx.doi.org/10.1055/a-1696-4553.

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Abstract (sommario):

AbstractThe cyclopropanation of alkenes through the transition-metal-catalyzed decomposition of diazo compounds is a powerful and straightforward strategy to produce cyclopropanes. Nevertheless, the appeal of further application of this strategy is tempered by the potentially explosive nature of the diazo substrates. Therefore, it is highly desirable to develop sustainable and operationally safe surrogates for diazo compounds. In this Synpacts article, we discuss recent advances on the cyclopropane syntheses through the catalytic cyclopropanation of alkenes and metal carbenes generated in situ from nondiazo precursors as well as highlight our recent progress on the unprecedented molybdenum-catalyzed deoxygenative cyclopropanation reaction of 1,2-dicarbonyl or monocarbonyl compounds.

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39

Luo, Hui-Xin, You-Hong Niu, Xiao-Ping Cao e Xin-Shan Ye. "Cyclopropenes for the Synthesis of Cyclopropane-Fused Dihydroquinolines and Benzazepines". Advanced Synthesis & Catalysis 357, n. 13 (10 settembre 2015): 2893–902. http://dx.doi.org/10.1002/adsc.201500203.

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40

Hara, Koji, Edmond I. Eger, Michael J. Laster e R. Adron Harris. "Nonhalogenated Alkanes Cyclopropane and Butane Affect Neurotransmitter-gated Ion Channel and G-protein–coupled Receptors". Anesthesiology 97, n. 6 (1 dicembre 2002): 1512–20. http://dx.doi.org/10.1097/00000542-200212000-00025.

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Abstract (sommario):

Background Anesthetic mechanisms of nonhalogenated alkanes cyclopropane and butane are not understood. This study was designed to look at which neurotransmitter receptors are possible targets for these anesthetics. Methods Effects of cyclopropane and butane on eight recombinant receptors expressed in Xenopus oocytes were examined electrophysiologically. To address molecular mechanisms of interaction with glycine and gamma-aminobutyric acid type A (GABA(A)) receptors, cyclopropane was further tested on alpha1(S267C) glycine receptor and alpha2(S270X)beta1 GABA(A) receptors that were mutated to amino acids with larger side chains. Results Cyclopropane (1, 2, and 5 minimum alveolar concentration [MAC]) potentiated glycine responses by 39, 62, and 161%, respectively, and butane (1 MAC) potentiated by 64% with an increase in apparent affinity for glycine, but yielded barely detectable potentiation of GABA(A) receptors. The efficacy of cyclopropane for glycine receptors was less than isoflurane and halothane. The potentiation by cyclopropane was eliminated for the alpha1(S267C) glycine receptor. Mutant GABA(A) receptors in which the corresponding amino acid was substituted with larger amino acids did not produce significant potentiation. Cyclopropane and butane inhibited nicotinic acetylcholine and N-methyl-D-aspartate receptors, potentiated G-protein-coupled inwardly rectifying potassium channels, and did not change 5-hydroxytryptamine(3A) or muscarinic(1) receptor function. Only cyclopropane markedly inhibited alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors. Conclusions Glycine, nicotinic acetylcholine, and N-methyl-D-aspartate receptors are sensitive to nonhalogenated alkanes, and the authors propose that glycine and N-methyl-D-aspartate receptors are good candidates for anesthetic immobility. The authors also suggest that the distinct effects on glycine and GABA(A) receptors are not due to the small volumes of these anesthetics.

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41

Liu, Yu, Qiao-Lin Wang, Zan Chen, Cong-Shan Zhou, Bi-Quan Xiong, Pan-Liang Zhang, Chang-An Yang e Quan Zhou. "Oxidative radical ring-opening/cyclization of cyclopropane derivatives". Beilstein Journal of Organic Chemistry 15 (28 gennaio 2019): 256–78. http://dx.doi.org/10.3762/bjoc.15.23.

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Abstract (sommario):

The ring-opening/cyclization of cyclopropane derivatives has drawn great attention in the past several decades. In this review, recent efforts in the development of oxidative radical ring-opening/cyclization of cyclopropane derivatives, including methylenecyclopropanes, cyclopropyl olefins and cyclopropanols, are described. We hope this review will be of sufficient interest for the scientific community to further advance the application of oxidative radical strategies in the ring-opening/cyclization of cyclopropane derivatives.

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42

Barkan, Daniel, Vivek Rao, George D. Sukenick e Michael S. Glickman. "Redundant Function of cmaA2 and mmaA2 in Mycobacterium tuberculosis cis Cyclopropanation of Oxygenated Mycolates". Journal of Bacteriology 192, n. 14 (14 maggio 2010): 3661–68. http://dx.doi.org/10.1128/jb.00312-10.

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Abstract (sommario):

ABSTRACT The Mycobacterium tuberculosis cell envelope contains a wide variety of lipids and glycolipids, including mycolic acids, long-chain branched fatty acids that are decorated by cyclopropane rings. Genetic analysis of the mycolate methyltransferase family has been a powerful approach to assign functions to each of these enzymes but has failed to reveal the origin of cis cyclopropanation of the oxygenated mycolates. Here we examine potential redundancy between mycolic acid methyltransferases by generating and analyzing M. tuberculosis strains lacking mmaA2 and cmaA2, mmaA2 and cmaA1, or mmaA1 alone. M. tuberculosis lacking both cmaA2 and mmaA2 cannot cis cyclopropanate methoxymycolates or ketomycolates, phenotypes not shared by the mmaA2 and cmaA2 single mutants. In contrast, a combined loss of cmaA1 and mmaA2 had no effect on mycolic acid modification compared to results with a loss of mmaA2 alone. Deletion of mmaA1 from M. tuberculosis abolishes trans cyclopropanation without accumulation of trans-unsaturated oxygenated mycolates, placing MmaA1 in the biosynthetic pathway for trans-cyclopropanated oxygenated mycolates before CmaA2. These results define new functions for the mycolic acid methyltransferases of M. tuberculosis and indicate a substantial redundancy of function for MmaA2 and CmaA2, the latter of which can function as both a cis and trans cyclopropane synthase for the oxygenated mycolates.

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43

Sathishkannan, Gopal, V. John Tamilarasan e Kannupal Srinivasan. "Nucleophilic ring-opening reactions of trans-2-aroyl-3-aryl-cyclopropane-1,1-dicarboxylates with hydrazines". Organic & Biomolecular Chemistry 15, n. 6 (2017): 1400–1406. http://dx.doi.org/10.1039/c6ob02552h.

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Abstract (sommario):

trans-2-Aroyl-3-aryl-cyclopropane-1,1-dicarboxylates gave dihydropyrazoles when treated with arylhydrazines in refluxing EtOH, whereas they afforded cyclopropane-fused pyridazinones upon treatment with hydrazines in refluxing AcOH.

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44

Jalkanen, K. J., J. D. Gale, G. J. Jalkanen, D. F. McIntosh, A. A. El-Azhary e G. M. Jensen. "trans-1,2-Dicyano-cyclopropane and other cyano-cyclopropane derivatives". Theoretical Chemistry Accounts 119, n. 1-3 (17 ottobre 2007): 211–29. http://dx.doi.org/10.1007/s00214-007-0391-6.

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45

Freedman, Teresa B., Diane L. Hausch, Steven J. Cianciosi e John E. Baldwin. "Kinetics of thermal racemization of (2S,3S)-1-13C-1,2,3-d3-cyclopropane followed by vibrational circular dichroism spectroscopy". Canadian Journal of Chemistry 76, n. 6 (1 giugno 1998): 806–10. http://dx.doi.org/10.1139/v98-070.

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Abstract (sommario):

Vibrational circular dichoism spectra recorded for (2S,3S)-1-13C-1,2,3-d3-cyclopropane and for mixtures of it and the three related stereoisomers prepared through gas-phase thermal stereomutation reactions at 407°C lead to the rate constant for racemization: kα = (4k1 + 4k12) = (3.12 ± 0.04) x 10-5 s-1. This and the rate constant measured for geometrical equilibration between the two chiral and the two achiral stereoisomers of 1-13C-1,2,3-d3-cyclopropane, ki = (8k1 + 4k12) = (4.63 ± 0.20) x 10-5 s-1, give two equations in two unknowns, and allow one to solve for one-center (k1) and two-center (k12) epimerization rate constants for cyclopropane stereomutations. They are nearly equal, a clear indication of closely competitive reaction pathways.Key words: cyclopropane stereomutations, thermal epimerizations, chirality through deuterium and carbon-13 labeling, vibrational circular dichroism.

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46

Budynina, Ekaterina, Konstantin Ivanov, Ivan Sorokin e Mikhail Melnikov. "Ring Opening of Donor–Acceptor Cyclopropanes with N-Nucleophiles". Synthesis 49, n. 14 (18 maggio 2017): 3035–68. http://dx.doi.org/10.1055/s-0036-1589021.

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Abstract (sommario):

Ring opening of donor–acceptor cyclopropanes with various N-nucleophiles provides a simple approach to 1,3-functionalized compounds that are useful building blocks in organic synthesis, especially in assembling various N-heterocycles, including natural products. In this review, ring-opening reactions of donor–acceptor cyclopropanes with amines, amides, hydrazines, N-heterocycles, nitriles, and the azide ion are summarized.1 Introduction2 Ring Opening with Amines3 Ring Opening with Amines Accompanied by Secondary Processes Involving the N-Center3.1 Reactions of Cyclopropane-1,1-diesters with Primary and Secondary Amines3.1.1 Synthesis of γ-Lactams3.1.2 Synthesis of Pyrroloisoxazolidines and -pyrazolidines3.1.3 Synthesis of Piperidines3.1.4 Synthesis of Azetidine and Quinoline Derivatives3.2 Reactions of Ketocyclopropanes with Primary Amines: Synthesis of Pyrrole Derivatives3.3 Reactions of Сyclopropane-1,1-dicarbonitriles with Primary Amines: Synthesis of Pyrrole Derivatives4 Ring Opening with Tertiary Aliphatic Amines5 Ring Opening with Amides6 Ring Opening with Hydrazines7 Ring Opening with N-Heteroaromatic Compounds7.1 Ring Opening with Pyridines7.2 Ring Opening with Indoles7.3 Ring Opening with Di- and Triazoles7.4 Ring Opening with Pyrimidines8 Ring Opening with Nitriles (Ritter Reaction)9 Ring Opening with the Azide Ion10 Summary

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47

Sedenkova, Kseniya N., Kristian S. Andriasov, Tamara S. Kuznetsova e Elena B. Averina. "Oxyfunctionalization of CH2-Group Activated by Adjacent Three-Membered Ring". Current Organic Synthesis 15, n. 4 (12 giugno 2018): 515–32. http://dx.doi.org/10.2174/1570179415666180405113158.

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Abstract (sommario):

Background: Increasing use of the three-membered ring in drug development initiates the search for efficient methods of transformations of cyclopropane derivatives. Oxidation of methylene group activated by an adjacent cyclopropane represents a direct approach towards carbonylcyclopropanes, allows avoiding unnecessary synthetic stages and meets the requirements of atom economy. Objective: In this review all available data concerning the oxidation of cyclopropane-containing hydrocarbons and their functionally substituted derivatives are systematized, and the general regularities between the structure of the starting compound, the oxidant employed and the reaction outcome are underlined. Conclusion: The following regularities were distinguished for the oxidation of cyclopropane-containing compounds into cyclopropylketones. The main structural parameters of the starting compounds, which influence the distribution of the oxidation products, are the followings: the presence of competing C-H bonds, flexibility or rigidity of structure, electron and sterical substituents effects. A number of preparative methods of activated C(sp3)-H bonds oxygenation were elaborated, employing such powerful oxidants as ozone, dioxiranes, CrO3 and a variety of catalytic systems, based on transition metals. For the oxidation of cyclopropane derivatives all these oxidants may be employed. RuO4, generated in situ, usually behaves as selective and soft oxidant. TFDO often demonstrates lesser selectivity, but it may be the best choice when several activated CH2 groups should be oxidised. In the case of dihalocyclopropanes the use of CrO3 is preferable. Summarily, the oxidation of methylene group adjacent to cyclopropane has been undoubtedly developed into a reliable preparative approach to cyclopropylketones, which should find an active use in synthetic organic chemistry.

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48

Wang, Lizhong, Zhenjie Su, Siran Qian, Weijian Ye e Cunde Wang. "Efficient Preparation of 2,3-Disubstituted Cyclopropane-1-Carbonitriles via Selective Decarboxylation of 1-Cyanocyclopropane-1-Carboxylates". Journal of Chemical Research 41, n. 11 (novembre 2017): 636–40. http://dx.doi.org/10.3184/174751917x15094552081161.

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Abstract (sommario):

2,3-Disubstituted cyclopropane-1-carbonitriles were efficiently formed via a selective decarboxylation reaction of substituted 2-aroyl-3-aryl-1-cyano-cyclopropane-1-carboxylates in up to 92% yield. The structures of three typical compounds were confirmed by X-ray crystallography.

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49

Xie, Yaoming, e Henry F. Schaefer. "Aluminirene (HAlC2H2) and aluminirane (HAlC2H4): aluminum-substituted counterparts of cyclopropene and cyclopropane". Journal of the American Chemical Society 112, n. 14 (luglio 1990): 5393–400. http://dx.doi.org/10.1021/ja00170a001.

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50

Al Dulayymi, Ahmad R., e Mark S. Baird. "2-Vinyl-1,1,2-trihalocyclopropanes-valuable five carbon cyclopropane and cyclopropene synthetic intermediates". Tetrahedron 52, n. 33 (agosto 1996): 10955–68. http://dx.doi.org/10.1016/0040-4020(96)00592-3.

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