Synthesis of Chiral 3-Pyrrolines from Propargyl Alcohols and N-Boc-amides

Significance

In this useful reaction sequence, the authors have first used a protocol for the enantioselective preparation of propargylic alcohols by the catalytic addition of alkynylzinc species to aldehydes. Then, a S_N2′ substitution of an α-aminomethylcopper derivative provides aminomethylallenes with high anti stereoselectivity. Finally, their silver-catalyzed cyclization furnishes a new method of the enantioselective preparation of Δ³-pyrrolines, which are an important class of biologically active compounds.