TfOH-catalyzed transfer hydrogenation reaction using 1-tetralone as a novel dihydrogen source

Abstract

An unprecedented TfOH-catalyzed transfer hydrogenation reaction has been developed using 1-tetralone as a novel dihydrogen source. Various alkenes, as well as triphenylmethyl and diphenylmethyl derivatives, have been successfully employed in this transfer hydrogenation reaction, resulting in the formation of various desired products with good yields. Deuterium labeling experiments show that the α-hydrogen of 1-tetralone donated a proton to the alkene, resulting in the formation of a carbenium ion that subsequently captured a hydride originating from the β-hydrogen of 1-tetralone, thereby facilitating a reduction reaction. This study represents a significant advance as it demonstrates the potential of ketones as novel dihydrogen sources for reduction reactions under metal-free conditions.