A simple and convenient photodecarboxylation method of intact carboxylic acids in the presence of aza aromatic compounds

Abstract

A very simple method of photodecarboxylation of intact carboxylic acids leading to alkanes is described which uses aza aromatic compounds as light absorbers and tert-butyl mercaptan as a hydrogen donor. This method is general and can be applied to various primary, secondary and tertiary carboxylic acids. The corresponding alkanes are usually produced in yields of 60%–80%. The formation of a ground state complex of the aza aromatic compounds with the carboxylic acids via hydrogen bonding is shown to be crucially important to the photodecarboxylation. Similar decarboxylation of α-hydroxycarboxylic acids in the absence of tert-butyl mercaptan under aerated conditions gives the corresponding carbonyl compounds in good yields.