Mechanism-based enhancement of scope and enantioselectivity for reactions involving a copper-substituted stereogenic carbon centre.

ABSTRACT: A rapidly emerging set of catalytic reactions involves intermediates that contain a copper-substituted stereogenic carbon centre. Here, we demonstrate that an intimate understanding of this distinction provides ways for addressing limitations in reaction scope and explaining why unexpected variations in enantioselectivity often occur. By using catalytic enantioselective Cu-boryl addition to alkenes as the model process, we elucidate several key mechanistic principles. We show that higher electrophile concentration can lead to elevated enantioselectivity. This is because diastereoselective Cu-H elimination may be avoided and/or achiral Cu-boryl intermediates can be converted to allyl-B(pin) rather than add to an alkene. We illustrate that lower alkene amounts and/or higher chiral ligand con

SUBMITTER: Lee J 

PROVIDER: S-EPMC5753601 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature