Studies on ZnBr2-mediated synthesis of axially chiral aryl-substituted allenes from terminal alkynes, aromatic aldehydes and (S)-α,α-diphenylprolinol

The studies on the ZnBr2-mediated synthesis of axially chiral aryl-substituted allenes from terminal alkynes, aromatic aldehydes, and commercially available chiral amine (S)-α,α-diphenylprolinol were conducted. Axially chiral aryl-substituted allenes can be obtained in moderate yields with up to 96% ee.