Download PDF
Synfacts 2007(4): 0368-0368  
DOI: 10.1055/s-2007-968367
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Ir-Catalyzed Selective C-7 Borylation of 2-Substituted Indoles

Contributor(s): Victor Snieckus, Yigang Zhao
S. Paul, G. A. Chotana, D. Holmes, R. C. Reichle, R. E. Maleczka, Jr.*, M. R. Smith, III*
Michigan State University, East Lansing, USA
Further Information

Publication History

Publication Date:
23 March 2007 (online)

    Permissions and Reprints

Significance

Reported is an Ir-catalyzed selective C-7 borylation of 2-substituted indoles using pinacolborane. Conditions are mild, the Ir catalyst is moderately stable and the yields are modest to excellent. C-2-unsubstituted indoles give 2-borylated products and, with excess of reagent, 2,7-diborylated indoles. Three mechanistic proposals are presented; based on D experiments, a process of indole N-Ir coordination to direct C-H insertion followed by borylation is favored.