Chromium/Photoredox Dual Catalyzed Synthesis of α-Benzylic Alcohols, Isochromanones, 1,2-Oxy Alcohols and 1,2-Thio Alcohols.

Abstract

Herein, a Cr/Photoredox-catalyzed general synthetic strategy to access α-benzylic alcohols, isochromanones, oxy alcohols and thio alcohols is unveiled. Alkylation of aldehydes being a crucial C-C bond forming reaction, designing competent catalytic systems would render an attractive and decorated set of diverse alcohol motifs. Considering the challenges associated with classical organometallic chemistry, the strategy of dual catalysis is applied here to generate diverse alcohol motifs in a mild and efficient manner. The amalgamation of photocatalysis with chromium chemistry is chosen for this purpose to generate an environment with low basicity and thus, high chemoselectivity. With alkyl silanes as preferred coupling partners, this catalytic setup produces a broad substrate scope with an excellent functional group tolerance and displays a facile scale-up as well. Its application towards biologically relevant molecules and product diversification contributes to the synthetic utility of this method.