A General Enantioselective C-H Arylation Using an Immobilized Recoverable Palladium Catalyst

Abstract

We herein report a general and efficient enantioselective C-H arylation of aryl bromides based on the use of BozPhos as the bisphosphine ligand and SP-NHC-Pd^II as recoverable heterogeneous catalyst. By exploiting the "release and catch" mechanism of action of the catalytic system, we used BozPhos as a broadly applicable chiral ligand, furnishing high enantioselectivities across all types of examined substrates containing methyl, cyclopropyl and aryl C-H bonds. For each reaction, the reaction scope was investigated, giving rise to 30 enantioenriched products, obtained with high yields and enantioselectivities, and minimal palladium leaching. The developed catalytic system provides a more sustainable solution compared to homogeneous systems for the synthesis of high added-value chiral products through recycling of the precious metal.

Keywords: C−H activation; enantioselectivity; heterocycles; heterogeneous catalysis; palladium.