Copper(I) halide promoted diastereoselective synthesis of chiral propargylamines and chiral allenes using 2-dialkylaminomethylpyrrolidine, aldehydes, and 1-alkynes.

Copper bromide promoted reactions of aldehydes, 1-alkynes, and chiral 2-dialkylaminomethylpyrrolidine at 25 °C give the corresponding chiral propargylamine derivatives in up to 96% yield and 99:1 dr that are readily converted to the corresponding disubstitued chiral allenes in up to 81% yield and 99% ee upon reaction with CuI in dioxane at 100 °C.