Catalytic Asymmetric Alkynylation of C1‐Substituted C,N‐Cyclic Azomethine Imines by Cu I /Chiral Brønsted Acid Co‐Catalyst

It all adds up : The title reaction was developed for the synthesis of chiral tetrahydroisoquinoline derivatives with a tetrasubstituted carbon center at the C1‐position (see scheme, Bz=benzoyl, pybox=2,6‐bis(2‐oxazolinyl)pyridine). The reaction was facilitated effectively by the co‐catalyst system composed of copper(I)/Ph‐pybox and an axially chiral dicarboxylic acid.