Addition of Boron Trifluoride Complexes of Alkylcopper, Dialkylcuprate( I ), and Alkynyllithium to A ldimines Containing α-Hydrogens

Abstract

An efficient method for the nucleophilic addition of organometallic reagents to imines is reported. RCu⋅BF₃, generated in situ from Grignard reagents, CuI and BF₃⋅Et₂, was added to aldimines without deprotonation of a-hydrogen to afford secondary amines in good yields, , (57∼85%). Boron trifluoride complex of dialkylcuprate( I ) gave essentially the same re sults with wider application. Furthermore, alkynyltrifluoroborates, prepared in situ from alkynyllithium and BF₃⋅OEt₂, were added to aldimines containing α-hydrogens to afford α-(1alkynyl)amines in good yields (57∼82%).