A novel approach to the selective preparation of 4-bromoindoles was developed via Pd(OAc)(2)/rac-BINAP catalytic reactions. A variety of 4,6-dibromoindoles were transformed to 4-bromoindoles with high regioselectivity. This methodology, along with C-N and C-O bond-forming reactions developed in our laboratory, was applied to the enantioselective synthesis of indolodioxane U86192A, an antihypertensive agent.
“Palladium-Catalyzed Regioselective Hydrodebromination of Dibromoindoles: Application to the Enantioselective Synthesis of Indolodioxane U86192A”, J. Org. Chem., 2004, 69(10), 3336-3339.