Catalytic asymmetric synthesis of optically active allenes from terminal alkynes

Article abstract of DOI:10.1021/ol300296k

CuBr and ZnI₂ have been developed as catalysts or subcatalysts for the efficient asymmetric synthesis of axially chiral allenols with up to 97% ee from readily available propargylic alcohols, aliphatic or aromatic aldehyde, pyrrolidine, and commerically available ligands. The alcohol unit in the terminal alkynes plays a very important role for ensuring high enantioselectivity via coordination.