Photo-induced oxidative esterification via aldehyde and alkyl halides using dimethyl carbonate as green solvent

Abstract

For a practical and environmentally benign strategy, we have devised an innovative approach for esterification in green dimethyl carbonate (DMC). Moreover, we employed a compatible system comprising abundantly available aldehydes and halides catalyzed using simple and commercial eosin Y under photocatalytic conditions. This strategy offers merits such as readily accessible feedstocks, remarkable functional tolerance and transition metal–free conditions, which allows to access wide scope of substrates with 34 examples and up to 93 % yield. Notably, cinnamaldehyde and 3-phenylpropiolaldehyde could accomplish this transformation while preserving CC unsaturated bonds. The density functional theory calculations (DFT) reveal that this transformation might undergo photoexcitation of the aldehyde to produce an acyl radical, which could further oxidatively esterify with halides to generate corresponding esters.