Ni(II)-Mediated Photochemical Oxidative Esterification of Aldehydes with Phenols.

The photopromoted, Ni-catalyzed acceptorless dehydrogenation esterification of phenols and aromatic aldehydes has been achieved in an oxidant- and external photosensitizer-free manner. This reliable and atom-economical transformation was tolerant to a wide range of functional groups and proceeded efficiently to give various aryl benzoates in moderate to high yields. Additionally, this photocatalytic system displayed high activity for the hydrogen-evolution cross coupling of aliphatic aldehydes and phenols employing dual nickel and aromatic aldehyde catalysis.

Visible-Light-Induced Nickel-Catalyzed P(O)-C(sp2) Coupling Using Thioxanthen-9-one as a Photoredox Catalysis.

An efficient method has been developed for photocatalytic P(O)-C(sp2) coupling of (hetero)aryl halides with H-phosphine oxides or H-phosphites under the irradiation of visible light or sunlight. The thioxanthen-9-one/nickel dual catalysis mediates this phosphonylation to give arylphosphine oxides and arylphosphonates in moderate to excellent yields. This transformation is widely tolerant to a range of functional groups and proceeds efficiently on a gram scale.