General CuBr ₂ -catalyzed highly enantioselective approach for optically active allenols from terminal alkynols

Here, we show a CuBr2-catalyzed approach for a highly enantioselective synthesis (93-99% ee) of allenols from aldehydes and terminal alkynols with the absolute configuration being controlled by applying readily available (R)- or (S)-α,α-diphenylprolinol.