Integrated continuous flow/batch protocol for the photoreduction of ortho-methyl phenyl ketones using water as the hydrogen source

Direct utilization of the abundant hydrogen in water for the transfer hydrogenation reaction (THR) is a very attractive and challenging research area. Herein, we report the first integrated photo-transfer hydrogenation reaction (PTHR) platform for the synthesis of benzhydrol derivatives (26 examples, 33-89% yields) with water as a green reducing agent. This transformation is time and labor-efficient, catalyst-free, and economical and utilizes readily available hydrocarbon(s) (o-methyl phenyl ketones) as starting materials.