Heterogeneous Chiral Diene-Rh Complexes for Asymmetric Arylation of α,β-Unsaturated Carbonyl Compounds, Nitroalkenes, and Imines

A chiral diene ligand with tertiary alkyl amine-derived secondary amide moiety was immobilized on cross-linked polystyrene (PS) by radical polymerization, which was combined with Rh to form heterogeneous chiral Rh complexes (PS-diene Rh−Cl). PS-diene Rh−Cl catalyzed asymmetric arylation reactions of α,β-unsaturated carbonyl compounds (ketones, esters, and amides), nitroalkenes, and imines afforded the desired products in high yields with excellent enantioselectivities. PS-diene Rh−Cl is stable in air, can be stored for several months, and can be reused more than 10 times without any reduction of either yield or enantioselectivity. We also developed a method of activation of PS-diene Rh−Cl to generate more active species. (Figure presented.).