N-Heterocyclic Carbene–Cu-Catalyzed Enantioselective Allenyl Conjugate Addition

• DOI: 10.1021/acs.orglett.8b03029
• Publication Date: 2018-10-16T18:55:09Z
• Authors: Qinglei Chong; Shuoqing Zhang; Fengchang Cheng; Jiping Wang; Xin Hong; Fanke Meng
• Keywords: Conjugate; Pinacol

A catalytic enantioselective conjugate addition with commercially available allenylboronic acid pinacol ester as nucleophile promoted by a chiral copper complex of N-heterocyclic carbene (NHC) is disclosed. This process constitutes an unprecedented instance the that introduces allenyl group into α,β-unsaturated carbonyl compounds, affording products are otherwise difficult to access in up 92% yield, >98% selectivity and 96:4 enantiomeric ratio. DFT calculations were performed elucidate origins enantioselectivity.