Rh-Catalyzed C–H activation/intramolecular condensation for the construction of benzo[f]pyrazolo[1,5-a][1,3]diazepines

Abstract

A novel and mild Rh(III)-catalyzed C–H activation/intramolecular condensation of 1-aryl-1H-pyrazol-5-amines with cyclic 2-diazo-1,3-diketones was developed, giving access to various important benzo[f]pyrazolo[1,5-a][1,3]diazepine scaffolds through sequential C–C/C–N bond formation in a one-pot procedure under additive- and oxidant-free conditions. Furthermore, 3-([1,1′-biphenyl]-2-ylamino)-2-ethoxycyclohex-2-enones can be obtained in good yields by constructing C–O and C–N bonds through 1,1′-insertion, dehydration, and isomerization processes.