Rh(III)-Catalyzed Double C-H Functionalization of Indoles with Cyclopropenones via Sequential C-H/C-C/C-H Bond Activation.

An unprecedented Rh(III)-catalyzed double C-H functionalization of indoles with cyclopropenones via sequential C-H/C-C/C-H bond activation has been developed. This procedure represents the first example for assembling of cyclopenta[ b ]indoles utilizing cyclopropenones as 3C synthons. This powerful approach shows excellent chemo- and regioselectivity, wide functional group tolerance, and good reaction yields.