title: Enantioselective synthesis of homoallylic amines through reactions of (pinacolato)allylborons with aryl-, heteroaryl-, alkyl-, or alkene-substituted aldimines catalyzed by chiral C1-symmetric NHC-Cu complexes.
abstract: A catalytic method for enantioselective synthesis of homoallylamides through Cu-catalyzed reactions of stable and easily accessible (pinacolato)allylborons with aryl-, heteroaryl-, alkyl-, or alkenyl-substituted N-phosphinoylimines is disclosed. Transformations are promoted by 1-5 mol % of readily accessible NHC-Cu complexes, derived from C(1)-symmetric imidazolinium salts, which can be prepared in multigram quantities in four steps from commercially available materials. Allyl additions deliver the desired products in up to quantitative yield and 98.5:1.5 enantiomeric ratio and are amenable to gram-scale operations. A mechanistic model accounting for the observed selectivity levels and trends is proposed.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
authors.forename: Erika M
authors.initials: EM
authors.lastname: Vieira
authors.forename: Marc L
authors.initials: ML
authors.lastname: Snapper
authors.forename: Amir H
authors.initials: AH
authors.lastname: Hoveyda
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000588:Amines / Q000138:chemical synthesis*; D001895:Boron / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D000588:Amines; D003300:Copper; D001895:Boron