The Concept of Photozymes: Short Peptides with Photoredox Catalytic Activity for Nucleophilic Additions to α‐Phenyl Styrenes
作者:Daniel Sack、Hans‐Achim Wagenknecht
DOI:10.1002/ejoc.202101068
日期:2021.12.14
Keep the substrate until “mission is completed”: The forward and backward electron transfer steps in a photoredoxcatalytic cycle are controlled substrate bindings to photocatalytically active peptides, the “photozymes”.
Under blue-light irradiation conditions with a photocatalyst [1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene], silyl enol ethers reacted with alkenes in the presence of a smallamount of water to afford the α-alkylation products in good to high yields. A thiol cocatalyst was found to expand the substrate scope of the reaction.
Trityl Antimonate-Catalyzed Sequential Reactions of Epoxides with Silylated Nucleophiles. Rearrangement of Epoxides and C–C or C–O Bond Forming Nucleophilic Reaction onto the Intermediate Carbonyl Compounds
作者:Tsunehiro Harada、Teruaki Mukaiyama
DOI:10.1246/bcsj.66.882
日期:1993.3
In the presence of a catalytic amount of trityl hexafluoroantimonate, sequential reactions of epoxides with silylated nucleophiles, rearrangement of epoxides and C–C or C–O bond forming nucleophilic reaction onto the intermediate carbonylcompounds, proceed smoothly to afford the corresponding products in fairly good yields by one-pot procedure. Trityl hexafluoroantimonate (5 mol %) efficiently promotes
Methanol-Incorporated Photoaddition of<i>N</i>-Methyl-9,10-phenanthrenedicarboximide to Alkenes. Addition at Carbonyl and Phenanthrene-Ring Carbon Atoms
Irradiation of acetonitrile–methanol (2:1 v/v) solutions of N-methyl-9,10-phenanthrenedicarboximide (3) with alkenes 5a–g gave methanol-incorporated adducts (9c–f) at a carbonyl carbon atom in 3, those (10c,f) at a phenanthrene-ring carbon atom, and a methanol-adduct 11g to alkene 5g, together with products 4, 6b,e–g, 7b,e–g, and 8e,f obtained by the photoreactions in benzene. The concentration effect of
Photochemical electron-transfer reactions of 1,1-diarylethylenes
作者:Susan L. Mattes、Samir. Farid
DOI:10.1021/ja00283a034
日期:1986.11
constant for nucleophilic addition of methanol to 1a/sup .+/ is 1.6 x 10/sup 9/ M/sup -1/s/sup -1/; for addition to 1b/sup .+/ it is approx.10/sup 7/ M/sup -1/s/sup -1/. Methanol does not add efficiently to 1c/sup .+ / . Photooxygenation of the diarylethylene yields mainly the corresponding 3,3,6,6-tetraaryl-1,2-dioxane in a chain process. In the presence of methanol and oxygen, 1a yields mainly 1-hyd