An efficient chiral porous catalyst support – Hypercrosslinked amino acid polymer.

By using aromatic amino acid as the starting material, a novel chiral catalyst support, porous hypercrosslinked amino acid polymer was synthesized, the recyclable asymmetric metal supported by it catalyzed efficient asymmetric reaction with high ee% (up to 99%). [Display omitted] • Synthesis of a new chiral catalyst support, porous hypercrosslinked amino acid (HCP-AA). • A new heterogeneous asymmetric catalyst. • High enantioselectivity of HCP-AA-Rh for asymmetric hydrosilylation of ketones and olefins (ee% up to 99%). • HCP-AA-Rh can be easily recycled and well maintain the catalytic performance after recycle. The application of asymmetric catalysis in industrial processes is limited by the high cost of chiral ligands and the difficulty associated with recovering precious metal catalysts. Here, based on a FeCl 3 -catalyzed Friedel–Crafts alkylation reaction, an aromatic amino acid was crosslinked with 4,4′-bis(chloromethyl)-1,1′-biphenyl to produce a novel porous chiral catalyst support, hypercrosslinked amino acid polymer (HCP-AA). Subsequently, metal catalysts were loaded on HCP-AA through the coordination of the metal ion with amino acid residues to generate heterogeneous asymmetric catalysts, HCP-AA-M. The resulting catalysts were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The HCP-AA-M samples were employed to catalyze the heterogeneous asymmetric reaction, and they achieved high enantioselectivities (up to 99% ee). Meanwhile, the catalysts could be readily recovered through filtration, and they exhibited good recycling performances. The results suggested that the utilization of inexpensive amino acids as raw materials for producing porous chiral supports for recyclable high-performance asymmetric catalysts is an effective strategy. [ABSTRACT FROM AUTHOR]