Merging visible-light photoredox and Lewis acid catalysis for the functionalization and arylation of glycine derivatives and peptides
作者:Shaoqun Zhu、Magnus Rueping
DOI:10.1039/c2cc36995h
日期:——
A relay catalysis protocol for the functionalization of α-amino acids and dipeptides using a combination of visible-light photoredox and Lewis acid catalysis has been developed.
The multi-component Friedel–Crafts alkylation reaction between indole (1), ethylglyoxylate (2) and anilines (3a–f) gives, in analogy to the protocol of the old Passerini reaction, the expected ethyl 2-(arylamino)-2-(1H-indol-3-yl)acetates 4a–f. When the reactions are catalysed by 5 mol-% scandiumtriflate (ScIIITf), however, or when the isolated products 4 are treated under the same conditions, rearrangements
AbstractA simple and efficient copper(I) chloride‐catalyzed aerobic oxidative coupling of glycine derivatives (glycine esters, glycine amides and short peptides) with indoles has been developed. The reaction is performed in the absence of any other additives under mild conditions and only requires simple copper salts as a catalyst and oxygen as a co‐oxidant.magnified image
The unprecedented title reaction between glycinederivatives and indoles, as well as the auto‐oxidative Povarov/aromatization tandem reaction of glycinederivatives with olefins are described. The reactions were performed in the absence of redox‐active catalysts and chemical oxidants under mild reaction conditions. Only simple organic solvents and air (or O2) were required.