Synthesis of Fused Indoles by Sequential Heck Reaction and N-Heteroannulation
B. C. G. Soderberg*, J. W. Hubbard, S. R. Rector, S. N. O’Neil
West Virginia University, Morgantown, USA
21 September 2005 (online)
A new synthetic route to 3,4-fused indoles by two Pd-catalyzed reactions - intramolecular Heck and reductive N-heteroannulation - is reported. Indoles with various ring sizes (6-8) anchored to the 3- and 4- position of the indole nucleus may be prepared by this method. A number of functional groups (e.g., Me, Ph, Ac, CO2Me) tolerate the conditions of this route. Both heteroatom (N, O) containing and carbocyclic rings may be anellated to the indole moiety with acceptable yields.