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Polarity‐Reversed Allylations of Aldehydes, Ketones, and Imines Enabled by Hantzsch Ester in Photoredox Catalysis
Author(s) -
Qi Li,
Chen Yiyun
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201607813
Subject(s) - umpolung , chemistry , photoredox catalysis , ketyl , reactivity (psychology) , polarity (international relations) , photochemistry , radical , intermolecular force , combinatorial chemistry , catalysis , substrate (aquarium) , chemoselectivity , organic chemistry , molecule , photocatalysis , medicine , biochemistry , oceanography , alternative medicine , pathology , geology , nucleophile , cell
The polarity reversal (umpolung) reaction is an invaluable tool for reversing the chemical reactivity of carbonyl and iminyl groups, which subsequent cross‐coupling reactions to form C−C bonds offers a unique perspective in synthetic planning and implementation. Reported herein is the first visible‐light‐induced polarity‐reversed allylation and intermolecular Michael addition reaction of aldehydes, ketones, and imines. This chemoselective reaction has broad substrate scope and the engagement of alkyl imines is reported for the first time. The mechanistic investigations indicate the formation of ketyl (or α‐aminoalkyl) radicals from single‐electron reduction, where the Hantzsch ester is crucial as the electron/proton donor and the activator.