Download PDF
Synfacts 2007(4): 0359-0359  
DOI: 10.1055/s-2007-968369
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Gold-Catalyzed Synthesis of Azepino[4,5-b]indoles and Indoloazocines

Contributor(s): Victor Snieckus, Heiko Scharl
C. Ferrer, C. H. M. Amijs, A. M. Echavarren*
Institute of Chemical Research of Catalonia, Tarragona, Spain
Further Information

Publication History

Publication Date:
23 March 2007 (online)

    Permissions and Reprints

Significance

A gold-catalyzed intramolecular cyclizative alkynylation of tryptophan, tryptamine, and tryptophol derivatives to azepino[4,5-b]indoles and indoloazocines is reported. While indoloazocines are obtained from terminal alkynes (R1 = H) under Au(III) catalysis (8-endo-dig process), in contrast, azepino[4,5-b]indoles result using Au(I) catalysis. Methyl-substituted alkynes lead to tetracyclic systems or to allene-substituted indoles under Au(I) catalysis. Hypothetical mechanisms for some of these reactions are suggested.