Rh-catalyzed C–H allylation and annulation of N-arylpyrazolidinones with MBH adducts

Abstract

Rh-catalyzed (4+1)-annulation of N-arylpyrazolidinones with MBH adducts has been developed to furnish α-pyrazolo[1,2-a]indazole acrylates. Use of the MBH adduct as a C1 synthon, cascade C–C/C–N bond formation, use of air as the oxidant, a broad substrate scope and functional group diversity are its important practical features.