A stereochemical model and origins of selectivity for the rhodium-catalyzed hydroselenation of styrene

A deeper understanding of the mechanisms underlying transition metal-catalyzed transformation is crucial for developing innovative strategies to synthesize chiral organoselenium compounds. In this study, we developed and investigated a three-layer chirality relay model for the rhodium-catalyzed asymmetric hydroselenation of alkenes through density functional theory (DFT) calculations. In the back layer of this model, the four bulky substituents on the phosphorus atom of the bidentate chiral MeO-BIPHEP ligand were positioned on axial and equatorial bonds, thereby influencing the configuration of the middle layer. The middle layer involved the coordination of selenium to Rh(i) hydride. Carbon chirality in alkanes facilitated reductive elimination in the front layer. The independent gradient model based on the Hirshfeld partition (IGMH) analysis supports this model, and the origins of enantioselectivity were explained through the three-layer chirality relay mechanism. Additionally, computational results revealed that selenol exhibited higher reactivity compared with phenol and thiol. This difference was attributable to its lower bond dissociation energy.