Copper-Catalyzed Asymmetric Deconstructive Alkynylation of Cyclic Oximes

Abstract

A general asymmetric deconstructive alkynylation of cyclic oximes with terminal alkynes was reported using copper/chiral cinchona alkaloid-based N,N,P-ligand catalysts and used to produce more than 60 examples of enantioenriched γ- and δ-alkynyl nitriles in a highly functional group-compatible manner. A wide variety of low-cost terminal alkynes and easily available cyclic oximes with substituent diversity were found to be well tolerated with the current asymmetric transformation with good functional group tolerance. The resulting chiral alkynyl nitriles are intermediates, which could be converted into skeletally diverse chiral molecules, including δ-alkynyl amides, ε-alkenyl carbamate, and ζ-keto nitrile, under suitable reaction conditions.