Visible light photocatalytic reduction of aldehydes by Rh(iii)-H: a detailed mechanistic study.

ABSTRACT: The chemoselective photoreduction of aldehydes in the presence of ketones was achieved using triethanolamine (TEOA) as sacrificial electron donor, proflavine (PF) as photocatalyst and [Cp*Rh(iii)(bpy)Cl]Cl (Rhcat) as mediator. The reducing agent, which reacts with the carbonyl group was found to be [Cp*Rh(iii)(bpy)H]Cl (Rh(iii)-H). Contrary to formate-based reduction, its slow photochemical in situ generation enables to kinetically distinguish aldehydes from ketones. The inherent reactivity difference of the carbonyl compounds is transferred by the method into synthetically useful reaction selectivities. The substrate scope is broad with excellent yields. A detailed study of the reaction mechanism reveals that the photoreduction of the PF triplet and the subsequent reduction of the Rhcat l

SUBMITTER: Ghosh T 

PROVIDER: S-EPMC5654342 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature