Site-Selective α-Alkylation of 1,3-Butanediol Using a Thiophosphoric Acid Hydrogen Atom Transfer Catalyst

Abstract

Herein, we developed secondary-alcohol-selective C–H alkylation of 1,3-butane diol by combining an acridinium photoredox catalyst and a thiophosphoric acid hydrogen atom transfer (HAT) catalyst. The use of non-coordinating solvent such as dichloromethane (DCM) improved secondary α-alkoxy C–H selectivity by lowering bond dissociation energy (BDE) through intramolecular hydrogen bonding.