Photoredox/Pyridine N-Oxide Catalyzed Carbohydroxylation and Aminohydroxylation of α-Olefins

Abstract

Regioselective carbohydroxylation and aminohydroxylation of α-olefins were developed by a photoredox catalyst and pyridine N-oxide. This approach offers the catalytic and direct conversion of unactivated alkenes to a series of primary alcohols, including those bearing β-quaternary carbon centers and β-amino alcohols. The regioselective difunctionalization is enabled by the radical addition of α-olefin from the pyridine N-oxy radical, which is generated from readily available pyridine N-oxide via photoredox catalyzed single-electron oxidation. A combination of experimental and computational mechanistic studies was employed to lend support for the proposed reaction mechanism that proceeds via interwoven radical steps and polar substitution. The implications of this method for regioselective difunctionalization of α-olefins were further demonstrated by the examples of carboetherification, carboesterification, and lactone formation.