Preparation of mesoporous Cu₂O nanospheres for green synthesis in the enantioselective boron conjugate addition of α,β‐unsaturated chiral compounds in aqueous phase

Abstract

Chiral organoboron compounds are essential intermediates in various significant reactions. However, there are still few efficient catalysts for their synthesis. This paper reports a novel catalytic material for chiral asymmetric boron conjugate addition reactions: mesoporous Cu₂O nanospheres (M‐Cu₂O). M‐Cu₂O is approximately 0.55 μm, exhibiting dense and uniformly distributed worm‐like pores. It features a specific surface area of 15.7 m²/g and an average pore size of 14.3 nm. Under the conditions of Toluene:H2O = 9:1, with a chiral ligand amount of 3.6 mol% and no additional base, it achieves a high yield (98% yield) and impressive enantioselectivity (98% ee ) for the template substrate chalcone using only 3.0 mol% of the catalyst. Notably, the catalyst can be easily recovered and maintains robust catalytic performance after seven cycles, yielding 92% and an ee value of 90%. This work presents a mild and effective method for synthesizing chiral boron compounds in an aqueous phase, significantly enhancing the application potential of mesoporous copper oxide nanospheres.