Progress in the synthesis of aldehydes from Pd-catalyzed Wacker-type reactions of terminal olefins

Abstract

Wacker-type reactions of terminal alkenes mainly lead to methyl ketones rather than aldehydes. The selective formation of aldehydes usually requires alkenes containing a suitable coordinating fragment. A few procedures however provide fair to high aldehyde/methyl ketone ratios in the absence of a directing group. This review, which is focused on the formation of aldehydes, summarizes the methods reported since 2007 and, with personal comments, the mechanisms and intermediates proposed to rationalize the regioselectivity. • This review highlights Wacker-type procedures leading to aldehydes from terminal alkenes and the corresponding mechanisms.