Rhodium(III)-Catalyzed [4+1] Oxidative Annulation of Amides with 1,3-enynes Through 1,4-Rhodium Migration

Rh(III)-catalyzed cascade oxidative C-H functionalization/aza-annulation of indole and pyrrole-N-carboxamides with 1,3-enynes involving 1,4-rhodium migration is disclosed. This [4+1] annulation protocol provides an approach for the synthesis of imidazo[1,5-a]indol-3(2H)-ones from easily accessible substrates. Moreover, sulfonamides are also found to be well compatible in this method, leading to the corresponding benzo[d]sultams. The efficacy of this protocol is highlighted by handy downstream conversions of the dienyl-sultam.

Automated summary

This paper reports the Rh(III)-catalyzed cascade oxidative C-H functionalization/aza-annulation of indole and pyrrole-N-carboxamides with 1,3-enynes involving 1,4-rhodium migration. It provides an approach for the synthesis of imidazo[1,5-a]indol-3(2H)-ones from easily accessible substrates. The compatibility of sulfonamides in this method is also demonstrated, leading to the corresponding benzo[d]sultams.