Catalytic Asymmetric Hydrogenation of (Z)-α-Dehydroamido Boronate Ester: A Direct Entry to Alkyl-substituted α-Amidoboronic Ester
The direct catalytic asymmetric hydrogenation of (Z)-α-dehydroamino boronate ester was realized. Using this approach, a class of therapeutically relevant alkyl-substituted α-amidoboronic ester was easily synthesized in high yields with generally excellent enantioselectivities (up to 99% yield, 99% ee). The utility of the product had been demonstrated by transformation to their corresponding boronic acid derivatives, Pd-catalyzed borylation reaction and an efficient synthesis of the potential intermediate of bortezomib. The clean, atom-economic and environment friendly process of this catalytic asymmetric hydrogenation process would make this approach a new alternative for the production of alkyl-substituted α-amidoboronic ester of great potential in the area of organic synthesis and medicinal chemistry.