Synergistic Interplay between Ligand and Metal-Centered Chirality in Iridium-Catalyzed Enantioselective C(sp3)-H Borylation of Cyclopropanols

Abstract

Density functional theory calculations were performed to investigate the Ir/CBL-catalyzed C(sp3)-H borylation of cyclopropanols. The computations indicate that the reaction follows an Ir(III)/Ir(V) catalytic cycle with six-and seven-coordinate intermediates, involving both Λ-and Δ-configured iridium species. The metal-centered chirality plays a key role in deter-mining enantioselectivity. The orthosubstituent on the N-aryl group of the ligand has significant impact on the Δ-configured C(sp3)-B reductive elimination, which can modulate the relative reactivity of the Λ-and Δ-configured intermediates, accounting for the experimentally observed enantioselectivities. The results reveal a synergistic interplay between ligand and metal-centered chirality, which together dictate the observed enantioselectivity.