Efficient enantioselective hydrogenation of quinolines catalyzed by conjugated microporous polymers with embedded chiral BINAP ligand

Chiral Ir complexes were successfully used in the asymmetric hydrogenation of olefins, ketones, and quinolines. However, almost all the catalytic systems could not tolerate a high catalyst loading because of the formation of an irreversible iridium dimer and trimer during the reaction. It is expected that higher catalytic activity may be achieved if the Ir-complexes were isolated in space. The development of conjugated microporous polymers (CMPs) gives the opportunity for the spatial separation of the complexes. A series of chiral CMPs based on the chiral (R)-BINAP ligand (BINAP-CMPs) with different surface areas were synthesized. The BINAP ligands were separately distributed in the framework and were three times more active than the homogeneous catalyst (TOF 340 h−1VS 100 h−1) for the asymmetric hydrogenation of quinolines.

Graphical AbstractA series of chiral BINAP-CMPs with different surface areas were synthesized which were three times more active than the homogeneous BINAP catalyst (TOF 340 h−1VS 100 h−1) for the asymmetric hydrogenation of quinolines.Figure optionsDownload full-size imageDownload as PowerPoint slide