Construction of Chiral Frustrated Lewis Pair Framework for Efficient Asymmetric Hydrosilylation of Imines and Enantiomeric Separation

Abstract

ABSTRACT Construction of stable and highly crystalline chiral frustrated Lewis pair (FLP) frameworks can enhance their prospects for application in practical transformation reactions; however, the scarcity of synthetic approaches has strongly hindered the development of chiral FLP frameworks. Based on the conformational chirality theory, we successfully prepared a series of chiral Lewis base‐centered covalent organic frameworks (PCOFs) by leveraging the chiral memory effect during the dynamic cage‐to‐COF transformation. Subsequent integration of these PCOFs with tris(pentafluorophenyl)borane afforded chiral FLP frameworks (CFLPs), which efficiently catalyzed the asymmetric hydrogenation of imines. CFLP‐1 exhibited optimal catalytic performance, facilitating the hydrosilylation of imines with a product yield exceeding 99% and an enantiomeric excess (ee) of 85%. CFLP‐1 was then deposited onto a nylon membrane to fabricate a CFLP‐nylon composite membrane. This modification not only significantly enhanced the reaction rate but also enabled chiral resolution of the product, achieving a turnover frequency (TOF) of 209.37 h − 1 and an ee value of 98%. These results demonstrate that the novel CFLP material has broad application prospects in heterogeneous asymmetric catalysis and enantiomeric separation.