Highly Enantioselective Catalytic Alkynylation of Ketones – A Convenient Approach to Optically Active Propargylic Alcohols

The development of highly enantioselective catalysts involving Cu(OTf)₂ and chiral camphorsulfonamides for the alkynylation of ketone is described. The influences of Lewis acids, reaction conditions and chiral ligands on the outcome of the reaction are discussed. The best enantioselectivity (up to 97 % ee) was obtained in the alkynylation of 2′‐chloroacetophenone. The scope of the reaction is also examined.