Amine-flavin electron transfer photochemistry. Potential models for monoamine oxidase catalysis and inhibition
摘要:
The photoreactions of 3-methyllumiflavin (3MLF) and a variety of amines have been explored. These studies have demonstrated that 3MLF undergoes efficient photoreactions with alpha-silyl tertiary benzylamines to generate 4a-adducts by pathways involving sequential SET and desilylation followed by radical coupling. These adducts are unstable substances that react rapidly with nucleophiles (e.g., MeOH, H2O, and NaBH4) and oxygen. They are also photolabile, providing the corresponding 4a-benzyldihydroflavin upon irradiation. Non-silicon-containing primary and secondary amines also participate in SET-promoted photoreactions with 3MLF. The amine cation radicals formed in these processes undergo further transformations to produce radical intermediates by either alpha-CH or NH deprotonation pathways. The potential relevance of these findings to the area of monoamine oxidase chemistry is considered.
Anodic Oxidation of (Trimethylsilyl)methanes with π-Electron Substituents in the Presence of Nucleophiles
作者:Toshio Koizumi、Toshio Fuchigami、Tsutomu Nonaka
DOI:10.1246/bcsj.62.219
日期:1989.1
It was found that oxidation potentials of methanes with π-electron substituents were decreased by introduction of a trimethylsilyl group. The anodicoxidation of benzyl-, allyl-, aryl(or alkyl)thiomethyl-, and aryloxymethyl-substituted trimethylsilanes smoothly proceeded in the presence of nucleophiles, e.g. alcohols and carboxylic acids, to eliminate the trimethylsilyl groups giving the corresponding
Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond
作者:Kelvin Pak Shing Cheung、Daria Kurandina、Tetsuji Yata、Vladimir Gevorgyan
DOI:10.1021/jacs.0c03993
日期:2020.6.3
A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugateddienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and ste-reoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O-
Catalyst free, visible-light promoted photoaddition reactions between C 60 and N- trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes
作者:Suk Hyun Lim、Dae Won Cho、Patrick S. Mariano
DOI:10.1016/j.tet.2017.11.064
日期:2018.1
aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C60 and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullereneadducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated
Method for the Synthesis of Amine-Functionalized Fullerenes Involving SET-Promoted Photoaddition Reactions of α-Silylamines
作者:Suk Hyun Lim、Jinju Yi、Gyeong Min Moon、Choon Sup Ra、Keepyung Nahm、Dae Won Cho、Kyungmok Kim、Tae Gyung Hyung、Ung Chan Yoon、Ga Ye Lee、Soojin Kim、Jinheung Kim、Patrick S. Mariano
DOI:10.1021/jo501034t
日期:2014.8.1
Observations made in this effort show that the use of EtOH in the solvent mixture is critical for efficient photoproduct formation. In contrast to typical thermal and photochemical strategies devised previously for the preparation of fullerene derivatives, the new photochemical approach takes place under mild conditions and does not require the use of excess amounts of substrates. Thus, the method
1,2-Amino Alcohols via Cr/Photoredox Dual-Catalyzed Addition of α-Amino Carbanion Equivalents to Carbonyls
作者:J. Luca Schwarz、Roman Kleinmans、Tiffany O. Paulisch、Frank Glorius
DOI:10.1021/jacs.9b12053
日期:2020.2.5
Herein, we report the synthesis of protected 1,2-aminoalcohols starting from carbonyl compounds (mostly aldehydes) and α-silyl amines. The reaction is enabled by a Cr/photoredox dual catalytic system that allows the in situ generation of α-amino carbanion equivalents which act as nucleophiles. The unique nature of this reaction was demonstrated through the aminoalkylation of ketones and an acyl silane