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Journal articles on the topic 'Indoline, aldehyde and C-H activation'

Author: Grafiati

Published: 6 September 2023

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1

Jafarpour, Farnaz, Azizollah Habibi, and Mehran Ghasemi. "Palladium/Norbornene Chemistry in the Synthesis of Polycyclic Indolines with Simple Nitrogen Sources." Synthesis 52, no. 14 (March 27, 2020): 2092–98. http://dx.doi.org/10.1055/s-0039-1707988.

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An efficient procedure has been developed to synthesize indoline derivatives through a palladium-catalyzed Heck reaction/C–H activation/dual amination cascade in one pot. This constitutes the first intermolecular catalytic approach to directly access N-alkylindolines with a broad substrate scope in the absence of any ligands. This method highlights the use of readily available amines and ureas as the required nitrogen sources in building up the indoline core.

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2

Swamy, V. S. V. S. N., K. Vipin Raj, Kumar Vanka, Sakya S. Sen, and Herbert W. Roesky. "Silylene induced cooperative B–H bond activation and unprecedented aldehyde C–H bond splitting with amidinate ring expansion." Chemical Communications 55, no. 24 (2019): 3536–39. http://dx.doi.org/10.1039/c9cc00296k.

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3

Xu, Pan, Guoqiang Wang, Zhongkai Wu, Shuhua li, and Chengjian Zhu. "Rh(iii)-catalyzed double C–H activation of aldehyde hydrazones: a route for functionalized 1H-indazole synthesis." Chemical Science 8, no. 2 (2017): 1303–8. http://dx.doi.org/10.1039/c6sc03888c.

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4

Yuan, Yumeng, Xiemin Guo, Xiaofeng Zhang, Buhong Li, and Qiufeng Huang. "Access to 5H-benzo[a]carbazol-6-ols and benzo[6,7]cyclohepta[1,2-b]indol-6-ols via rhodium-catalyzed C–H activation/carbenoid insertion/aldol-type cyclization." Organic Chemistry Frontiers 7, no. 20 (2020): 3146–59. http://dx.doi.org/10.1039/d0qo00820f.

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5

Maia da Silva Santos, Bruno, Mariana dos Santos Dupim, Cauê Paula de Souza, Thiago Messias Cardozo, and Fernanda Gadini Finelli. "DABCO-promoted photocatalytic C–H functionalization of aldehydes." Beilstein Journal of Organic Chemistry 17 (December 21, 2021): 2959–67. http://dx.doi.org/10.3762/bjoc.17.205.

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Herein we present a direct application of DABCO, an inexpensive and broadly accessible organic base, as a hydrogen atom transfer (HAT) abstractor in a photocatalytic strategy for aldehyde C–H activation. The acyl radicals generated in this step were arylated with aryl bromides through a well stablished nickel cross-coupling methodology, leading to a variety of interesting aryl ketones in good yields. We also performed computational calculations to shine light in the HAT step energetics and determined an optimized geometry for the transition state, showing that the hydrogen atom transfer between aldehydes and DABCO is a mildly endergonic, yet sufficiently fast step. The same calculations were performed with quinuclidine, for comparison of both catalysts and the differences are discussed.

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6

Zhang, Qiao, Angela Bell-Taylor, Fraser M. Bronston, John D. Gorden, and Christian R. Goldsmith. "Aldehyde Deformylation and Catalytic C–H Activation Resulting from a Shared Cobalt(II) Precursor." Inorganic Chemistry 56, no. 2 (December 22, 2016): 773–82. http://dx.doi.org/10.1021/acs.inorgchem.6b02127.

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7

Török, Patrik, Dóra Lakk-Bogáth, and József Kaizer. "Stoichiometric Alkane and Aldehyde Hydroxylation Reactions Mediated by In Situ Generated Iron(III)-Iodosylbenzene Adduct." Molecules 28, no. 4 (February 15, 2023): 1855. http://dx.doi.org/10.3390/molecules28041855.

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Previously synthesized and spectroscopically characterized mononuclear nonheme, low-spin iron(III)-iodosylbenzene complex bearing a bidentate pyridyl-benzimidazole ligands has been investigated in alkane and aldehyde oxidation reactions. The in situ generated Fe(III) iodosylbenzene intermediate is a reactive oxidant capable of activating the benzylic C-H bond of alkane. Its electrophilic character was confirmed by using substituted benzaldehydes and a modified ligand framework containing electron-donating (Me) substituents. Furthermore, the results of kinetic isotope experiments (KIE) using deuterated substrate indicate that the C-H activation can be interpreted through a tunneling-like HAT mechanism. Based on the results of the kinetic measurements and the relatively high KIE values, we can conclude that the activation of the C-H bond mediated by iron(III)–iodosylbenzene adducts is the rate-determining step.

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8

Seo, Jia, Che-Wei Chen, Shih-Ching Chuang, Jung Min Joo, Woohyeong Lee, Ju Eun Jeon, and Pei-Ling Chen. "Palladium-Catalyzed C–H Benzannulation of Functionalized Furans and Pyrroles with Alkynes." Synthesis 53, no. 17 (May 6, 2021): 3001–10. http://dx.doi.org/10.1055/a-1502-3641.

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AbstractA benzannulation strategy involving activation of two C–H bonds of five-membered heteroarenes was developed. Readily available furans and pyrroles stabilized by synthetically useful electron-withdrawing groups underwent Pd-catalyzed 1:2 annulation reactions with diaryl alkynes. A variety of functional groups, including ester, amide, ketone, aldehyde, and nitrile, on the heterocyclic cores were tolerated in the Pd-catalyzed oxidative reactions. In these reactions, the combination of 2,2-dimethylbutyric acid and its conjugate base facilitated metalation at the heteroaromatic rings and reoxidation of the Pd(0) species using oxygen as the terminal oxidant. This strategy provides fluorescent benzofuran and indole derivatives and is expected to allow for further development of functionalized polycyclic heteroaromatic compounds.

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9

Massouh, Joe, Antoine Petrelli, Virginie Bellière‐Baca, Damien Hérault, and Hervé Clavier. "Rhodium(III)‐Catalyzed Aldehyde C−H Activation and Functionalization with Dioxazolones: An Entry to Imide Synthesis." Advanced Synthesis & Catalysis 364, no. 4 (December 29, 2021): 831–37. http://dx.doi.org/10.1002/adsc.202101099.

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10

Bertini, Simone, and Martin Albrecht. "O-Functionalised NHC Ligands for Efficient Nickel-catalysed C–O Hydrosilylation." CHIMIA International Journal for Chemistry 74, no. 6 (June 24, 2020): 483–88. http://dx.doi.org/10.2533/chimia.2020.483.

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A series of C,O-bidentate chelating mesoionic carbene nickel(ii) complexes [Ni(NHC^PhO)2] (NHC = imidazolylidene or triazolylidene) were applied for hydrosilylation of carbonyl groups. The catalytic system is selective towards aldehyde reduction and tolerant to electron-donating and -withdrawing group substituents. Stoichiometric experiments in the presence of different silanes lends support to a metal–ligand cooperative activation of the Si–H bond. Catalytic performance of the nickel complexes is dependent on the triazolylidene substituents. Butyl-substituted triazolylidene ligands impart turnover numbers up to 7,400 and turnover frequencies of almost 30,000 h-1, identifying this complex as one of the best-performing nickel catalysts for hydrosilylation and demonstrating the outstanding potential of O-functionalised NHC ligands in combination with first-row transition metals.

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11

Garralda, María A. "Aldehyde C–H activation with late transition metal organometallic compounds. Formation and reactivity of acyl hydrido complexes." Dalton Transactions, no. 19 (2009): 3635. http://dx.doi.org/10.1039/b817263c.

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12

Zhang, Yicheng, Pinhua Li, Min Wang, and Lei Wang. "Indium-Catalyzed Highly Efficient Three-Component Coupling of Aldehyde, Alkyne, and Amine via C−H Bond Activation." Journal of Organic Chemistry 74, no. 11 (June 5, 2009): 4364–67. http://dx.doi.org/10.1021/jo900507v.

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13

Du, Jin, Wei Chen, Gangfeng Wu, Yanfang Song, Xiao Dong, Guihua Li, Jianhui Fang, Wei Wei, and Yuhan Sun. "Evoked Methane Photocatalytic Conversion to C2 Oxygenates over Ceria with Oxygen Vacancy." Catalysts 10, no. 2 (February 6, 2020): 196. http://dx.doi.org/10.3390/catal10020196.

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Direct conversion of methane to its oxygenate derivatives remains highly attractive while challenging owing to the intrinsic chemical inertness of CH4. Photocatalysis arises as a promising green strategy which could stimulate water splitting to produce oxidative radicals for methane C–H activation and subsequent C–C coupling. However, synthesis of a photocatalyst with an appropriate capability of methane oxidation by water remains a challenge using an effective and viable approach. Herein, ceria nanoparticles with abundant oxygen vacancies prepared by calcinating commercial CeO2 powder at high temperatures in argon are reported to capably produce ethanol and aldehyde from CH4 photocatalytic oxidation under ambient conditions. Although high-temperature calcinations lead to lower light adsorptions and increased band gaps to some extent, deficient CeO2 nanoparticles with oxygen vacancies and surface CeIII species are formed, which are crucial for methane photocatalytic conversion. The ceria catalyst as-calcinated at 1100 °C had the highest oxygen vacancy concentration and CeIII content, achieving an ethanol production rate of 11.4 µmol·gcat−1·h−1 with a selectivity of 91.5%. Additional experimental results suggested that the product aldehyde was from the oxidation of ethanol during the photocatalytic conversion of CH4.

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14

Ochoa, Carmen A., Claire G. Nissen, Deanna D. Mosley, Christopher D. Bauer, Destiny L. Jordan, Kristina L. Bailey, and Todd A. Wyatt. "Aldehyde Trapping by ADX-102 Is Protective against Cigarette Smoke and Alcohol Mediated Lung Cell Injury." Biomolecules 12, no. 3 (March 2, 2022): 393. http://dx.doi.org/10.3390/biom12030393.

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Most individuals diagnosed with alcohol use disorders smoke cigarettes. Large concentrations of malondialdehyde and acetaldehyde are found in lungs co-exposed to cigarette smoke and alcohol. Aldehydes directly injure lungs and form aldehyde protein adducts, impacting epithelial functions. Recently, 2-(3-Amino-6-chloroquinolin-2-yl)propan-2-ol (ADX-102) was developed as an aldehyde-trapping drug. We hypothesized that aldehyde-trapping compounds are protective against lung injury derived from cigarette smoke and alcohol co-exposure. To test this hypothesis, we pretreated mouse ciliated tracheal epithelial cells with 0–100 µM of ADX-102 followed by co-exposure to 5% cigarette smoke extract and 50 mM of ethanol. Pretreatment with ADX-102 dose-dependently protected against smoke and alcohol induced cilia-slowing, decreases in bronchial epithelial cell wound repair, decreases in epithelial monolayer resistance, and the formation of MAA adducts. ADX-102 concentrations up to 100 µM showed no cellular toxicity. As protein kinase C (PKC) activation is a known mechanism for slowing cilia and wound repair, we examined the effects of ADX-102 on smoke and alcohol induced PKC epsilon activity. ADX-102 prevented early (3 h) activation and late (24 h) autodownregulation of PKC epsilon in response to smoke and alcohol. These data suggest that reactive aldehydes generated from cigarette smoke and alcohol metabolism may be potential targets for therapeutic intervention to reduce lung injury.

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15

Liu, Hong Fei, Xin Min Min, and Hai Xia Yang. "Theoretical Investigation of the Decarbonylation of Acetaldehyde by Ni⁺²Using Density Functional Theory." Applied Mechanics and Materials 446-447 (November 2013): 168–71. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.168.

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The decarbonylation of acetaldehyde assisted by Ni+2, which was selected as a representative system of transition metal ions assisted decarbonylation of acetaldehyde, has been investigated using density functional theory (B3LYP) in conjunction with the 6-31+G** basis sets in C,H,O atoms and Lanl2dz basis sets in Ni atom The geometries and energies of the reactants, intermediates, products and transition states relevant to the reaction were located on the triplet ground potential energy surfaces of [Ni, O, C2,H4]+2. Our calculations indicate the decarbonylation of acetaldehyde takes place through four steps, that is, encounter complexation, CC activation, aldehyde H-shift and nonreactive dissociation, it is that CC activation by Ni+2that lead to the decarbonylation of acetaldehyde.

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16

Nguyen, Anh T., Lam T. Pham, Nam T. S. Phan, and Thanh Truong. "Efficient and robust superparamagnetic copper ferrite nanoparticle-catalyzed sequential methylation and C–H activation: aldehyde-free propargylamine synthesis." Catal. Sci. Technol. 4, no. 12 (July 23, 2014): 4281–88. http://dx.doi.org/10.1039/c4cy00753k.

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17

Corkey, Britton K., Felicia L. Taw, Robert G. Bergman, and Maurice Brookhart. "Aromatic and aldehyde carbon–hydrogen bond activation at cationic Rh(III) centers. Evaluation of electronic substituent effects on aldehyde binding and C–H oxidative addition." Polyhedron 23, no. 17 (November 2004): 2943–54. http://dx.doi.org/10.1016/j.poly.2004.09.005.

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18

Shi, Lei, Yong-Qiang Tu, Min Wang, Fu-Min Zhang, and Chun-An Fan. "Microwave-Promoted Three-Component Coupling of Aldehyde, Alkyne, and Amine via C−H Activation Catalyzed by Copper in Water." Organic Letters 6, no. 6 (March 2004): 1001–3. http://dx.doi.org/10.1021/ol049936t.

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19

Koh, Jae J., Wook-Hwan Lee, Paul G. Williard, and William M. Risen. "The PtP(C6H11)3(C2H4)2 mediated activation of aldehyde CH bonds via chelate-assisted oxidative addition reactions." Journal of Organometallic Chemistry 284, no. 3 (April 1985): 409–19. http://dx.doi.org/10.1016/0022-328x(85)80038-3.

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20

Alaimo, Peter J., Bruce A. Arndtsen, and Robert G. Bergman. "Synthesis of Tertiary and Other Sterically Demanding Alkyl and Aryl Complexes of Iridium by Aldehyde C−H Bond Activation." Journal of the American Chemical Society 119, no. 22 (June 1997): 5269–70. http://dx.doi.org/10.1021/ja970245k.

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21

Singh, Krishna, and Dushyant Raghuvanshi. "Highly Efficient Cadmium-Catalyzed Three-Component Coupling of an Aldehyde, Alkyne, and Amine via C-H Activation under Microwave Conditions." Synlett 2011, no. 03 (January 13, 2011): 373–77. http://dx.doi.org/10.1055/s-0030-1259323.

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22

Wei, Chunmei, and Chao-Jun Li. "A Highly Efficient Three-Component Coupling of Aldehyde, Alkyne, and Amines via C−H Activation Catalyzed by Gold in Water." Journal of the American Chemical Society 125, no. 32 (August 2003): 9584–85. http://dx.doi.org/10.1021/ja0359299.

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23

Ozawa, Fumiyuki, Isao Yamagami, and Akio Yamamoto. "Reaction of RuH2(PMe3)4 with benzaldehyde. Formation of novel oxametallacycle and metallacycloketone complexes via CH bond activation of aldehyde." Journal of Organometallic Chemistry 473, no. 1-2 (June 1994): 265–72. http://dx.doi.org/10.1016/0022-328x(94)80127-4.

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24

D’Amato, Assunta, Marco Sirignano, Simona Russo, Rubina Troiano, Annaluisa Mariconda, and Pasquale Longo. "Recent Advances in N-Heterocyclic Carbene Coinage Metal Complexes in A3-Coupling and Carboxylation Reaction." Catalysts 13, no. 5 (April 27, 2023): 811. http://dx.doi.org/10.3390/catal13050811.

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Owing of their accessibility and wide range of reactivities, alkynes make for fascinating building blocks. Either a selective alkyne carbon-carbon triple bond reaction or activation of the terminal alkyne C-H bond may be employed to functionalize them. Monocationic coinage metal complexes with a d10 electronic configuration are effective catalysts for alkyne activation. Silver(I) and gold(I) N-heterocyclic (NHC) systems are emerging as promising catalysts in multicomponent alkyne activation reactions; this review paper focuses on A3 (aldehyde-amine-alkyne)-coupling reaction and carbon dioxide fixation, furnishing a systematic overview of the scientific advances achieved during the last two decades. This study will carefully compare the corresponding silver and gold complexes employed in the two processes. The differences in reaction routes brought about by the catalyst ligand structure will be investigated with an emphasis on evaluating the benefits provided by the easily tuneable NHC backbone, in terms of chemo- and stereo-selectivity.

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25

Liu, Xingyan, Xiaoyu Li, Hu Liu, Qiang Guo, Jingbo Lan, Ruilin Wang, and Jingsong You. "Aldehyde as a Traceless Directing Group for Rh(III)-Catalyzed C–H Activation: A Facile Access to Diverse Indolo[1,2-a]quinolines." Organic Letters 17, no. 12 (May 29, 2015): 2936–39. http://dx.doi.org/10.1021/acs.orglett.5b01171.

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26

Raghuvanshi, Dushyant Singh, and Krishna Nand Singh. "ChemInform Abstract: Highly Efficient Cadmium-Catalyzed Three-Component Coupling of an Aldehyde, Alkyne, and Amine via C-H Activation under Microwave Conditions." ChemInform 42, no. 23 (May 12, 2011): no. http://dx.doi.org/10.1002/chin.201123079.

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27

Sahara, E., D. E. Permatasaari, and I. W. Suarsa. "PEMBUATAN DAN KARAKTERISASI ARANG AKTIF DARI BATANG LIMBAH TANAMAN GUMITIR DENGAN AKTIVATOR ZnCl2." Jurnal Kimia 13, no. 1 (January 16, 2019): 95. http://dx.doi.org/10.24843/jchem.2019.v13.i01.p15.

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The agricultural waste of gumitir plants stem can be used as an ingredient in producing an activated carbon. Some researchers have reported that the additions of phosphoric acid and NaOH as chemical activators have resulted in an activated carbon that met the SNI (Indonesian National Standard) 06-3730-1995 about technical activated carbon. The purpose of this study was to produce and characterize the activated carbon from the stem of gumitir plants carbonized at 300oC for 90 minutes with the use of ZnCl2 as the activator. The activation was carried out by adding ZnCl2 to an amount of carbon in various mole ratios. The characteristics of the activated carbon obtained were compared to the SNI. It was evident that the addition of 0.1 mole of ZnCl2 to 1 gram of the carbon produced an activated carbon that met the SNI standard, namely, water content of 5.00%, as content of 8.33%, volatile content of 950oC of heating of 7.36%, carbon content of 79,30%, iodine absorption capacity of 788.1271 mg/g, and methylene blue absorption capacity of 260.7917 mg/g. The surface area and surfae acidity of this carbon was of 677,6270 mg2/g and 0.3396 mmol/g, respectively. The functional group analysis of this activated carbon showed the presence of O-H, COOH, C-O aldehyde, alkaline C-C and C-H groups.

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28

Liu, Xingyan, Xiaoyu Li, Hu Liu, Qiang Guo, Jingbo Lan, Ruilin Wang, and Jingsong You. "ChemInform Abstract: Aldehyde as a Traceless Directing Group for Rh(III)-Catalyzed C-H Activation: A Facile Access to Diverse Indolo[1,2-a]quinolines." ChemInform 46, no. 44 (October 15, 2015): no. http://dx.doi.org/10.1002/chin.201544179.

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29

Lam, Hanh N. K., Nguyen B. Nguyen, Giao H. Dang, Thanh Truong, and Nam T. S. Phan. "Three-Component Coupling of Aldehyde, Alkyne, and Amine via C–H Bond Activation Using Indium-Based Metal–Organic Framework Mil-68(In) as a Recyclable Heterogeneous Catalyst." Catalysis Letters 146, no. 10 (August 27, 2016): 2087–97. http://dx.doi.org/10.1007/s10562-016-1805-7.

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30

CUNNINGHAM, Colm, F. Keith TIPTON, and B. F. Henry DIXON. "Conversion of taurine into N-chlorotaurine (taurine chloramine) and sulphoacetaldehyde in response to oxidative stress." Biochemical Journal 330, no. 2 (March 1, 1998): 939–45. http://dx.doi.org/10.1042/bj3300939.

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N-Chlorotaurine (taurine chloramine), formed by treating taurine with hypochlorous acid, was shown to decompose to sulphoacetaldehyde with a first-order rate constant of 9.9±0.5×10-4·h-1 at 37 °C in 0.1 M phosphate buffer, pH 7.4. Rat liver homogenates accelerated this decay in a process that was proportional to tissue-protein concentration and saturable, with maximum velocity (Vmax) and Km values of 0.28±0.01 nmol/min per mg of protein and 37±9 μM respectively. This activity was found to be lost on heat denaturation, but retained after dialysis. There was no detectable formation of sulphoacetaldehyde when taurine itself was incubated with the tissue homogenates under the same conditions. Activation of human neutrophils (1.67×106 cells/ml) with latex beads resulted in a respiratory burst of oxygen-radical production, the products of which were partially sequestered by 12.5 mM taurine. Under these conditions sulphoacetaldehyde was generated at a constant rate of 637±18 pmol/h per ml for over 7 h. A non-activated neutrophil suspension contained constant levels of 1.42±0.02 nmol/ml sulphoacetaldehyde, as did activated cells incubated in the absence of taurine, a basal level which may indicate a steady turnover of taurine in these cells. Such formation of chlorotaurine and its decay to the aldehyde may be the first steps in the metabolism of taurine to isethionate (2-hydroxyethanesulphonate) that has been demonstrated by various authors to occur in vivo.

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31

NEUHAUSER, Wilfried, Dietmar HALTRICH, Klaus D. KULBE, and Bernd NIDETZKY. "NAD(P)H-dependent aldose reductase from the xylose-assimilating yeast Candida tenuis: Isolation, characterization and biochemical properties of the enzyme." Biochemical Journal 326, no. 3 (September 15, 1997): 683–92. http://dx.doi.org/10.1042/bj3260683.

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During growth on D-xylose the yeast Candida tenuis produces one aldose reductase that is active with both NADPH and NADH as coenzyme. This enzyme has been isolated by dye ligand and anion-exchange chromatography in yields of 76%. Aldose reductase consists of a single 43 kDa polypeptide with an isoelectric point of 4.70. Initial velocity, product inhibition and binding studies are consistent with a compulsory-ordered, ternary-complex mechanism with coenzyme binding first and leaving last. The catalytic efficiency (kcat/Km) in D-xylose reduction at pH 7 is more than 60-fold higher than that in xylitol oxidation and reflects significant differences in the corresponding catalytic centre activities as well as apparent substrate-binding constants. The enzyme prefers NADP(H) approx. 2-fold to NAD(H), which is largely due to better apparent binding of the phosphorylated form of the coenzyme. NADP+ is a potent competitive inhibitor of the NADH-linked aldehyde reduction (Ki 1.5 μM), whereas NAD+ is not. Unlike mammalian aldose reductase, the enzyme from C. tenuisis not subject to oxidation-induced activation. Evidence of an essential lysine residue located in or near the coenzyme binding site has been obtained from chemical modification of aldose reductase with pyridoxal 5′-phosphate. The results are discussed in the context of a comparison of the enzymic properties of yeast and mammalian aldose reductase.

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32

Zhou, Yu, Panpan Chen, Qingnian Liu, Yingchao Wang, Ling Zhang, Rongrong Wu, Jinghai Chen, et al. "Hepatoma-Derived Growth Factor Secreted from Mesenchymal Stem Cells Reduces Myocardial Ischemia-Reperfusion Injury." Stem Cells International 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/1096980.

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Objectives. The present study aimed to explore the major factors that account for the beneficial effects of mesenchymal stem cells (MSCs). Methods. Using isobaric tags for relative and absolute quantitation method, hepatoma-derived growth factor (HDGF) was identified as an important factor secreted by MSCs, but not by cardiac fibroblasts (CFs). The protective effects of conditioned medium (CdM) from MSCs or CFs were tested by using either H9C2 cells that were exposed by hypoxia-reoxygenation (H/R) insult or an in vivo mouse model of myocardial ischemia-reperfusion. Results. Compared to CF-CdM, MSC-CdM conferred protection against reperfusion injury. CdM obtained from MSCs that were treated with HDGF-targeted shRNA failed to offer any protection in vitro. In addition, administration of recombinant HDGF alone recapitulated the beneficial effects of MSC-CdM, which was associated with increased protein kinase C epsilon (PKCε) phosphorylation, enhanced mitochondria aldehyde dehydrogenase family 2 activity, and decreased 4-hydroxy-2-nonenal accumulation. A significant decrease in infarct size and ameliorated cardiac dysfunction was achieved by administration of HDGF in wild-type mice, which was absent in PKCε dominant negative mice, indicating the essential roles of PKCε in HDGF-mediated protection. Conclusions. HDGF secreted from MSCs plays a key role in the protection against reperfusion injury through PKCε activation.

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33

Li, Pinhua, and Lei Wang. "A highly efficient three-component coupling of aldehyde, terminal alkyne, and amine via C–H activation catalyzed by reusable immobilized copper in organic–inorganic hybrid materials under solvent-free reaction conditions." Tetrahedron 63, no. 25 (June 2007): 5455–59. http://dx.doi.org/10.1016/j.tet.2007.04.032.

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34

Moccia, Fabio, Luca Rigamonti, Alessandro Messori, Valerio Zanotti, and Rita Mazzoni. "Bringing Homogeneous Iron Catalysts on the Heterogeneous Side: Solutions for Immobilization." Molecules 26, no. 9 (May 6, 2021): 2728. http://dx.doi.org/10.3390/molecules26092728.

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Noble metal catalysts currently dominate the landscape of chemical synthesis, but cheaper and less toxic derivatives are recently emerging as more sustainable solutions. Iron is among the possible alternative metals due to its biocompatibility and exceptional versatility. Nowadays, iron catalysts work essentially in homogeneous conditions, while heterogeneous catalysts would be better performing and more desirable systems for a broad industrial application. In this review, approaches for heterogenization of iron catalysts reported in the literature within the last two decades are summarized, and utility and critical points are discussed. The immobilization on silica of bis(arylimine)pyridyl iron complexes, good catalysts in the polymerization of olefins, is the first useful heterogeneous strategy described. Microporous molecular sieves also proved to be good iron catalyst carriers, able to provide confined geometries where olefin polymerization can occur. Same immobilizing supports (e.g., MCM-41 and MCM-48) are suitable for anchoring iron-based catalysts for styrene, cyclohexene and cyclohexane oxidation. Another excellent example is the anchoring to a Merrifield resin of an FeII-anthranilic acid complex, active in the catalytic reaction of urea with alcohols and amines for the synthesis of carbamates and N-substituted ureas, respectively. A SILP (Supported Ionic Liquid Phase) catalytic system has been successfully employed for the heterogenization of a chemoselective iron catalyst active in aldehyde hydrogenation. Finally, FeIII ions supported on polyvinylpyridine grafted chitosan made a useful heterogeneous catalytic system for C–H bond activation.

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35

Valinger, Z., P. C. Engel, and D. E. Metzler. "Is pyridoxal 5′-phosphate an affinity label for phosphate-binding sites in proteins?: The case of bovine glutamate dehydrogenase." Biochemical Journal 294, no. 3 (September 15, 1993): 835–39. http://dx.doi.org/10.1042/bj2940835.

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The effects of pyridoxal 5′-phosphate (PalP) on ox liver glutamate dehydrogenase (94% inactivation by 1.8 mM reagent at pH 7 and 25 degrees C) have been compared with those of three analogues, 5′-deoxypyridoxal (96% inactivation), pyridoxal 5′-sulphate (97%) and pyridoxal 5-methylsulphonate (94%), in order to establish whether PalP acts as an affinity label for this enzyme. Like PalP and unlike pyridoxal, which is a much less potent inactivator, none of the analogues has a free 5′-OH group to cyclize with the aldehyde function. The result with 5′-deoxypyridoxal shows that a negative charge, such as that of the phosphate group, is not required for efficient inactivation. With all four reagents, addition of an excess of cysteine or lysine led to 90-100% re-activation over 3-20 h. Dialysis also caused reactivation to a similar extent. A combination of 2.15 mM NADH, 1 mM GTP and 10 mM 2-oxoglutarate gave complete protection against PalP, but only partial protection against the analogues. 5′-Deoxypyridoxal still caused 20-25% inactivation in the presence of the protection mixture. Absorbance measurements after reduction with NaBH4 show the characteristic features of a reduced Schiff's base and allowed estimation of the extent of reaction. With all the reagents the protection mixture decreased incorporation by about 1 mol/mol, but levels of incorporation without protection varied from about 2 mol/mol for PalP up to about 5 mol/mol for 5′-deoxypyridoxal. The labelling at additional sites may explain the residual inactivation in the presence of potent protecting agents.

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36

Raji Reddy, Chada, Srinivas Bodasu, Kathe Mallesh, and Y. Lakshmi Prapurna. "Synthesis of Fused Pyrimido[1,6-a]indolones via Rhodium(III)-Catalyzed Cascade Annulations." Synthesis, October 12, 2020. http://dx.doi.org/10.1055/s-0040-1707312.

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AbstractA novel method for the synthesis of fused pyrimido[1,6-a]-indolone derivatives by annulation of 2-alkynylaryl aldehydes/2-alkynylarylidene ketones with N-(pivaloyloxy)-1H-indole-1-carboxamide catalyzed by rhodium has been accomplished. The reaction proceeds through C–H activation based annulation with alkyne moiety followed by addition of nitrogen on to aldehyde/activated alkene to give the products in moderate to good yields. Highly fluorescent dipyrrinone analogues could be synthesized from the derived products.

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37

Zheng, Miao, Jianhui Zhou, Feifei Fang, Zichao Xu, Fuqiang Zheng, Zhidong Jiang, Tao Liu, Hong Liu, Linxiang Zhao, and Yu Zhou. "A Substrate-controlled Ru(II)-catalyzed C-H Activation/[5+2] Annulation Cascade and Unusual Acyl Migration to Diversified Indoline Scaffolds." Organic Chemistry Frontiers, 2022. http://dx.doi.org/10.1039/d2qo01529c.

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A substrate-controlled Ru(II)-catalyzed C-H activation/[5+2] annulation cascade and unusual acyl migration to synthesize diversified indoline scaffolds were reported. The most pronounced advantage is that this strategy can offer a highly...

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38

Sansano, José, Asmaa Belabbes, Francisco Foubelo, Carmen Najera, Gracia Retamosa, Ana Sirvent, and Miguel Yus. "pseudo-Multicomponent 1,3-dipolar cycloaddition involving a metal-free generation of unactivated azomethine ylides." Organic & Biomolecular Chemistry, 2023. http://dx.doi.org/10.1039/d3ob00023k.

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The pseudo-multicomponent reaction between propargyl amine, an aldehyde and an electron-deficient alkene is described. The C-H activation takes place thermally and allows to obtain cicloadducts in very good yields and...

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39

Shan, Zi-Wei, Xiao-Yan Chen, Hao Zhang, Hai-Yang Liu, and Gaoqing Yuan. "Copper Porphyrin-catalyzed C(sp3)-H Activation via Cross Dehydrogenative Coupling: Facile Transformation of Aldehydes to Esters." Synlett, March 31, 2022. http://dx.doi.org/10.1055/a-1813-4235.

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Copper porphyrin-catalyzed alkane C−H bond functionalization with aldehydes via cross dehydrogenative coupling (CDC) using DTBP oxidant has been firstly described in non-solvents or non-additives system. Different aryl/heteroaryl-carboxilic esters were obtained in good to excellent yields depending on the aldehyde derivatives. This CDC reaction catalyzed by copper porphyrin has the advantages of shorter reaction time, lower reaction temperature and catalyst loading as well as the aerobic reaction atmosphere.

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40

Meng, Fan-Tao, Ya-Nan Wang, Xiao-Yan Qin, Shi-Jun Li, Jing Li, Wen-Juan Hao, Shu-Jiang Tu, Yu Lan, and Bo Jiang. "Azoarene activation for Schmidt-type reaction and mechanistic insights." Nature Communications 13, no. 1 (December 1, 2022). http://dx.doi.org/10.1038/s41467-022-35141-4.

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AbstractThe Schmidt rearrangement, a reaction that enables C-C or C-H σ bond cleavage and nitrogen insertion across an aldehyde or ketone substrate, is one of the most important and widely used synthetic tools for the installation of amides and nitriles. However, such a reaction frequently requires volatile, potentially explosive, and highly toxic azide reagents as the nitrogen donor, thus limiting its application to some extent. Here, we show a Schmidt-type reaction where aryldiazonium salts act as the nitrogen precursor and in-situ-generated cyclopenta-1,4-dien-1-yl acetates serve as pronucleophiles from gold-catalyzed Nazarov cyclization of 1,3-enyne acetates. Noteworthy is that cycloketone-derived 1,3-enyne acetates enabled ring-expansion relay to access a series of 2-pyridone-containing fused heterocycles, in which nonsymmetric cycloketone-derived counterparts demonstrated high regioselectivity. Aside from investigating the scope of this Schmidt-type reaction, mechanistic details of this transformation are provided by performing systematic theoretical calculations.

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41

Garralda, Maria A. "ChemInform Abstract: Aldehyde C-H Activation with Late Transition Metal Organometallic Compounds: Formation and Reactivity of Acyl Hydrido Complexes." ChemInform 40, no. 38 (September 22, 2009). http://dx.doi.org/10.1002/chin.200938255.

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42

Zhang, Yicheng, Pinhua Li, Min Wang, and Lei Wang. "ChemInform Abstract: Indium-Catalyzed Highly Efficient Three-Component Coupling of Aldehyde, Alkyne, and Amine via C-H Bond Activation." ChemInform 40, no. 43 (October 27, 2009). http://dx.doi.org/10.1002/chin.200943049.

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43

Shi, Lei, Yong-Qiang Tu, Min Wang, Fu-Min Zhang, and Chun-An Fan. "Microwave-Promoted Three-Component Coupling of Aldehyde, Alkyne, and Amine via C—H Activation Catalyzed by Copper in Water." ChemInform 35, no. 31 (August 3, 2004). http://dx.doi.org/10.1002/chin.200431077.

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44

Wei, Chunmei, and Chao-Jun Li. "A Highly Efficient Three-Component Coupling of Aldehyde, Alkyne, and Amines via C—H Activation Catalyzed by Gold in Water." ChemInform 34, no. 47 (November 25, 2003). http://dx.doi.org/10.1002/chin.200347071.

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45

Khake, Shrikant M., and Naoto Chatani. "Rh(III)-Catalyzed [3 + 2] Annulation of Aniline Derivatives with Vinylsilanes via C–H Activation/Alkene Cyclization: Access to Highly Regioselective Indoline Derivatives." ACS Catalysis, September 22, 2021, 12375–83. http://dx.doi.org/10.1021/acscatal.1c03603.

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46

Schwinger, Daniel P., Martin T. Peschel, Thomas Rigotti, Piotr Kabaciński, Thomas Knoll, Erling Thyrhaug, Giulio Cerullo, Jürgen Hauer, Regina de Vivie-Riedle, and Thorsten Bach. "Photoinduced B–Cl Bond Fission in Aldehyde-BCl₃ Complexes as a Mechanistic Scenario for C–H Bond Activation." Journal of the American Chemical Society, October 7, 2022. http://dx.doi.org/10.1021/jacs.2c06683.

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47

Rhlee, Joon Ho, Saikat Maiti, Jeong Woo Lee, Ho Seung Lee, Ismoili Ahror Bakhtiyorzoda, Soochan Lee, Jaehyun Park, et al. "Synthesis of α,β-unsaturated ketones through nickel-catalysed aldehyde-free hydroacylation of alkynes." Communications Chemistry 5, no. 1 (February 3, 2022). http://dx.doi.org/10.1038/s42004-022-00633-3.

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Abstractα,β-Unsaturated ketones are common feedstocks for the synthesis of fine chemicals, pharmaceuticals, and natural products. Transition metal-catalysed hydroacylation reactions of alkynes using aldehydes have been recognised as an atom-economical route to access α,β-unsaturated ketones through chemoselective aldehydic C–H activation. However, the previously reported hydroacylation reactions using rhodium, cobalt, or ruthenium catalysts require chelating moiety-bearing aldehydes to prevent decarbonylation of acyl-metal-hydride complexes. Herein, we report a nickel-catalysed anti-Markovnikov selective coupling process to afford non-tethered E-enones from terminal alkynes and S-2-pyridyl thioesters in the presence of zinc metal as a reducing agent. Utilization of a readily available thioester as an acylating agent and water as a proton donor enables the mechanistically distinctive and aldehyde-free hydroacylation of terminal alkynes. This non-chelation-controlled approach features mild reaction conditions, high step economy, and excellent regio- and stereoselectivity.

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48

Khatik, Gopal L., Ramesh Ambatwar, Vaibhav Gupta, and Sumit Kumar. "Biginelli Reaction: A Multi-Component Type of Reaction and Synthetic Advancement in the Synthesis of Bioactive Dihydropyrimidinone Derivatives." Mini-Reviews in Organic Chemistry 20 (June 1, 2023). http://dx.doi.org/10.2174/1570193x20666230601093704.

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Background: In synthetic and medicinal chemistry, multi-component reactions (MCRs) are considered an essential tool in synthesizing bioactive heterocyclic scaffolds. These reactions have been strategically used in drug discovery and development because of ease and economy. Objective: The current manuscript aims to highlight the importance of the Biginelli reaction in the synthesis of diverse dihydropyrimidinones with medicinal applications. Methods: We searched various keywords, including “multicomponent reaction”, “Biginelli reaction” and “dihydropyrimidinone” on “PubMed, PubChem, and google scholar” and collected the relevant articles for including the current work. Results: Biginelli reaction involving ketoester, aldehyde, and urea is a high-yielding, atom-economical, environmentally benign reaction for developing a library of new dihydropyrimidinones to drive the process of drug discovery. Several developments were achieved with modifications of synthetic techniques, including C-H activation, coupling, cycloaddition, etc. Inclusively, these modifications give access to a wide range of dihydropyrimidinones.

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JUN, C. H. "ChemInform Abstract: C-H Bond Activation of Aldimine by Rh(I): New Synthesis of β,γ-Unsaturated Ketone from Aldehyde Through Iminoacylrhodium(III)-η3-allyl Complexes." ChemInform 21, no. 48 (November 27, 1990). http://dx.doi.org/10.1002/chin.199048114.

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50

Tsai, Hsiao-Ya, Yu-Juei Hsu, Cheng-Yo Lu, Min-Chien Tsai, Wan-Chu Hung, Po-Chuan Chen, Jen-Chun Wang, et al. "Pharmacological Activation Of Aldehyde Dehydrogenase 2 Protects Against Heatstroke-Induced Acute Lung Injury by Modulating Oxidative Stress and Endothelial Dysfunction." Frontiers in Immunology 12 (October 26, 2021). http://dx.doi.org/10.3389/fimmu.2021.740562.

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Heatstroke (HS) can cause acute lung injury (ALI). Heat stress induces inflammation and apoptosis via reactive oxygen species (ROS) and endogenous reactive aldehydes. Endothelial dysfunction also plays a crucial role in HS-induced ALI. Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that detoxifies aldehydes such as 4-hydroxy-2-nonenal (4-HNE) protein adducts. A single point mutation in ALDH2 at E487K (ALDH2*2) intrinsically lowers the activity of ALDH2. Alda-1, an ALDH2 activator, attenuates the formation of 4-HNE protein adducts and ROS in several disease models. We hypothesized that ALDH2 can protect against heat stress-induced vascular inflammation and the accumulation of ROS and toxic aldehydes. Homozygous ALDH2*2 knock-in (KI) mice on a C57BL/6J background and C57BL/6J mice were used for the animal experiments. Human umbilical vein endothelial cells (HUVECs) were used for the in vitro experiment. The mice were directly subjected to whole-body heating (WBH, 42°C) for 1 h at 80% relative humidity. Alda-1 (16 mg/kg) was administered intraperitoneally prior to WBH. The severity of ALI was assessed by analyzing the protein levels and cell counts in the bronchoalveolar lavage fluid, the wet/dry ratio and histology. ALDH2*2 KI mice were susceptible to HS-induced ALI in vivo. Silencing ALDH2 induced 4-HNE and ROS accumulation in HUVECs subjected to heat stress. Alda-1 attenuated the heat stress-induced activation of inflammatory pathways, senescence and apoptosis in HUVECs. The lung homogenates of mice pretreated with Alda-1 exhibited significantly elevated ALDH2 activity and decreased ROS accumulation after WBH. Alda-1 significantly decreased the WBH-induced accumulation of 4-HNE and p65 and p38 activation. Here, we demonstrated the crucial roles of ALDH2 in protecting against heat stress-induced ROS production and vascular inflammation and preserving the viability of ECs. The activation of ALDH2 by Alda-1 attenuates WBH-induced ALI in vivo.

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