Enantioselective A(3) reactions of secondary amines with a Cu(I)/acid-thiourea catalyst combination.

Pyrrolidine and related amines undergo asymmetric A(3) reactions in the presence of copper iodide and an easily accessible cocatalyst possessing both a carboxylic acid and a thiourea moiety. Propargylamines are obtained with up to 96% ee, and catalyst loadings can be as low as 1 mol %. Pyrrolidine-derived propargylamines, in the absence of directing groups, can be transformed to the corresponding allenes without loss of enantiopurity.