Autorecycling system for reduction of carbonyl compounds to alcohols by 1,5-dihydro-5-deazaflavins

Abstract

An effective recycling system for the reduction of carbonyl compounds to alcohols by 1,5-dihydro-5-deazaflavins, which were produced from 5-deazaflavins and formic acid in a circulatory system, was constructed for the first time, in such a way that the compound catalyses the reduction, by formic acid, of benzaldehyde. In particular, the reduction using 3,7-dimethyl-10-p-tolyl-5-deazaflavin at 120 °C for 50 h proceeded until the benzaldehyde substrate was exhausted to give 100% yield of benzyl alcohol. The yield based on the catalyst was 3120%, which means 31 recyclings of the catalyst.