Synthesis of 3-pyrrolines, annulated 3-pyrrolines, and pyrroles from alpha-Amino allenes

[GRAPHICS] alpha -Amino allenes, readily prepared from reaction of alpha-(N-carbamoyl) alkylcuprates with propargyl substrates followed by N-Boc deprotection, are converted in high yields to pyrrolines with AgNO3. Palladium-catalyzed cyc lization of amino allenes affords either the pyrroline or the pyrrole depen ding on reaction conditions and provides for introduction of an aryl substi tuent at the C-3 position of the pyrroline or pyrrole. Enantioenriched pyrr olines are readily prepared from scalemic propargyl alcohols.