Rhodium-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived ketimines: a facile and versatile approach to functionalized 3,3 ',3 ''-trisindoles

A simple, facile and efficient Rh-2(OAc)(4)-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived N-Boc ketimines towards a variety of functionalized 3,3',3 ''-trisindoles in high yields with moderate to excellent diastereoselectivities has been developed. This methodology provides an ideal approach for the direct introduction of indole and oxindole into an isatin moiety at the 3-position.