Hydroamination of Alkynes Catalyzed by a Cationic Rhodium(I) Complex

Abstract

The cationic Rh(I) dicarbonyl complex [{Rh((mim) 2 CH 2 )(CO) 2 } + BPh 4 - ] ( 1 ), containing a bidentate bisimidazolylmethane ligand [mim = N -methylimidazol-2-yl], acts as an efficient catalyst for the intramolecular hydroamination of both terminal and nonterminal alkynes. The complex catalyzes the regioselective formation of nitrogen-containing heterocycles from aliphatic aminoalkynes and the cyclization of o -alkynylanilines to 2-substituted indoles in high yield.