Insights into the mechanism of fatty acid photodecarboxylase: A theoretical investigation

Abstract

Fatty acid photodecarboxylase (FAP), was reported recently that can catalyze fatty acid decarboxylation to afford n-alkanes in blue light. A trimolecular photocycle mechanism involving an unidentified proton donor HX was proposed, which is seemingly incompatible with the observed high quantum yield (>80%). Herein, we present an energetic preferred bimolecular mechanism by DFT that involves FADH-based intermediates. Our present work suggests that the light-capturing organic molecule itself, lumiflavin (FI) of FAD, may act as a metal-free photocatalyst for the photodecarboxylation of fatty acids to afford hydrocarbons in organic synthesis.