Palladium-catalyzed regioselective hydrodebromination of dibromoindoles: application to the enantioselective synthesis of indolodioxane U86192A.

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.