Borenium-Catalyzed Reduction of Pyridines through the Combined Action of Hydrogen and Hydrosilane
Joshua J. Clarke, Yuuki Maekawa, Masakazu Nambo, Cathleen M. Crudden
Abstract
Mesoionic carbene-stabilized borenium ions efficiently reduce substituted pyridines to piperidines in the presence of a hydrosilane and a hydrogen atmosphere. Control experiments and deuterium labeling studies demonstrate reversible hydrosilylation of the pyridine, enabling full reduction of the N-heterocycle under milder conditions. The silane is a critical reaction component to prevent adduct formation between the piperidine product and the borenium catalyst.
Topics & Concepts
ChemistryCatalysisHydrosilylationPyridineAdductPiperidineHydrogenBorohydrideSilaneMesoionicBenzimidazoleCombinatorial chemistryOrganic chemistryMedicinal chemistryPhotochemistryOrganoboron and organosilicon chemistryCatalytic Cross-Coupling ReactionsAsymmetric Hydrogenation and Catalysis