Low-valent ruthenium complexes with a pi -acidic ligand, such as Ru(eta (6)
-cot)(dmfm)(2) [cot = 1,3,5-cyclooctatriene, dmfm = dimethyl fumarate] and
Ru-3(CO)(12), showed high catalytic activity for the intramolecular hydroam
ination of aminoalkynes. The reaction is highly regioselective, in which a
nitrogen atom is selectively attached to an internal carbon of alkynes to g
ive five-, six-, and seven-membered nitrogen heterocycles as well as indole
s in good to high yields. (C) 2001 Elsevier Science B.V. All rights reserve
d.