Ligand Conformational Flexibility Enables Enantioselective Tertiary C-B Bond Formation in the Phosphonate-Directed Catalytic Asymmetric Alkene Hydroboration.

ABSTRACT: Conformationally flexible ancillary ligands have been widely used in transition metal catalysis. However, the benefits of using flexible ligands are often not well understood. We performed density functional theory (DFT) and experimental studies to elucidate the mechanisms and the roles of conformationally flexible α,α,α',α'-tetraaryldioxolane-4,5-dimethanol (TADDOL)-derived ligands on the reactivity and selectivity in the Rh-catalyzed asymmetric hydroboration (CAHB) of alkenes. DFT calculations and deuterium labeling studies both indicated that the most favorable reaction pathway involves an unusual tertiary C-B bond reductive elimination to give high levels of regio- and enantioselectivities. Here, the asymmetric construction of the fully substituted carbon center is promoted by the flex

SUBMITTER: Shao H 

PROVIDER: S-EPMC8324071 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature