Universal one-pot strategy for fabricating supported chiral organocatalysts via direct covalent immobilization upon hollow mesoporous polystyrene nanospheres

Abstract

Heterogeneous asymmetric organocatalysis is severely limited by two problems: mult-step energy- and time-consuming covalent immobilization of expensive organocatalysts and difficulty in controlling the morphology and porous structure of supported organocatalysts. Herein, a universal strategy is presented for the direct covalent immobilization of structurally different chiral organocatalysts upon hollow mesoporous organic polystyrene nanospheres (HMOPNs) via a one-pot tandem reaction. Owing to the steric confinement and fast mass transfer originating from their hollow interior, thin shell thickness and abundant mesopores, these supported chiral organocatalysts show excellent catalytic performances in the stereo-controlled steps of the synthesis of natural products and pharmaceuticals in good to high yields (76–96%) with excellent enantioselectivities (93–99% ee). This one-pot immobiliza- tion strategy paves a universal way for direct covalent immobilization of chiral organocatalysts bearing phenyl/aryl moiety to fabricate supported chiral organocatalysts with good long-term performances, achieving the low-cost production of chiral molecules.