Transfer Hydrogenation of Carbonyl Groups, Imines andN‐Heterocycles Catalyzed by Simple, Bipyridine‐Based MnIComplexes

Abstract

AbstractUtilization of hydroxy‐substituted bipyridine ligands in transition metal catalysis mimicking [Fe]‐hydrogenase has been shown to be a promising approach in developing new catalysts for hydrogenation. For example, MnIcomplexes with 6,6′‐dihydroxy‐2,2′‐bipyridine ligand have been previously shown to be active catalysts for CO2hydrogenation. In this work, simple bipyridine‐based Mn catalysts were developed that act as active catalysts for transfer hydrogenation of ketones, aldehydes and imines. For the first time, Mn‐catalyzed transfer hydrogenation ofN‐heterocycles was reported. The highest catalytic activity among complexes with variously substituted ligands was observed for the complex bearing two OH groups in bipyridine. Deuterium labeling experiments suggest a monohydride pathway.