Rh(III)-Catalyzed C–H Activation/IntramolecularCyclization: Access to N-Acyl-23-dihydro-1H-carbazol-4(9H)-ones fromCyclic 2-Diazo-13-diketones and N-Arylamides

摘要

A Rh(III)-catalyzed C–H activation/cyclization cascade reaction is described. The reaction involves cyclic 2-diazo-1,3-diketones and N-arylamides, and it proceeds via an intermolecular C–C bond formation and subsequent intramolecular C–N bond formation. A variety of N-acyl-2,3-dihydro-1H-carbazol-4(9H)-ones were obtained under mild conditions in good to excellent yields (65–90%). Key features of this strategy include high-efficiency, operational simplicity, scalability, and broad functional-group tolerance. In addition, H2O and N2 are the only byproducts. Carbazole derivatives with free NH groups can be easily obtained through N-deprotection reactions.