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Stereocontrolled Synthesis of 1,4‐Dicarbonyl Compounds by Photochemical Organocatalytic Acyl Radical Addition to Enals
Author(s) -
Goti Giulio,
Bieszczad Bartosz,
VegaPeñaloza Alberto,
Melchiorre Paolo
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201810798
Subject(s) - chemistry , iminium , acylation , radical , enantioselective synthesis , organocatalysis , catalysis , reactivity (psychology) , stereoselectivity , conjugate , photochemistry , combinatorial chemistry , photoredox catalysis , organic chemistry , photocatalysis , medicine , mathematical analysis , alternative medicine , mathematics , pathology
We report a visible‐light‐mediated organocatalytic strategy for the enantioselective acyl radical conjugate addition to enals, leading to valuable 1,4‐dicarbonyl compounds. The process capitalizes upon the excited‐state reactivity of 4‐acyl‐1,4‐dihydropyridines that, upon visible‐light absorption, can trigger the generation of acyl radicals. By means of a chiral amine catalyst, iminium ion activation of enals ensures a stereoselective radical trap. We also demonstrate how the combination of this acylation process with a second catalyst‐controlled bond‐forming event allows to selectively access the full matrix of all possible stereoisomers of the resulting 2,3‐substituted 1,4‐dicarbonyl products.