Development of Immobilized Chiral Iridium Catalysts by Strengthening Coordination Bonds for Z-retentive Asymmetric Allylic Substitution

Abstract

Ir-catalyzed asymmetric allyl substitution is pivotal for constructing chiral compounds. However, addressing Ir scarcity and developing sustainable catalysts for industrial applications remains a significant challenge. This study presents a polymer-supported heterogeneous chiral single-Ir-site catalyst, wherein the coordination is optimized through modulation of anions, resulting in a significant reduction in metal leaching. The catalysts exhibit exceptional performance in terms of enhanced enantioselectivity and broad applicability in Z-retentive asymmetric allylic substitution reactions, even accommodating a wide range of diverse functional groups. Specifically, the catalyst demonstrates minimal metal leaching over 14 cycles, marking a notable improvement compared to previously reported catalysts. The practical optimization of this reaction highlights the potential application value of such catalysts, offering insights for the development of chiral heterogeneous catalysts.