Abstract
Experimental and theoretical mechanistic studies on the Cu(OTf) 2-catalyzed hydroamination reaction of terminal allenes with secondary amines reveal that in-situ generated cationic Cu(I) is the catalytically active species and explain the observed regio-and stereoselectivity for the unbranched E product. Insight about the structure of the relevant transition states allowed the generalization of this methodology to allenamides and N-allenylcarbamates under unprecedentedly mild and functional group tolerant conditions. Chelation effect by the amide oxygen in addition to electronic effects explain the high innate reactivity of this class of substrates.