Synthesis of pyrazolone fused benzodiazepines <i>via</i> Rh(<scp>iii</scp>)-catalyzed [4 + 3] annulation of 1-phenylpyrazolidinones with propargyl alcohols

Abstract

An efficient synthesis of pyrazolone fused benzodiazepines through an unprecedented regioselective [4 + 3] annulation of 1-phenylpyrazolidinones with propargyl alcohols <italic>via</italic> Rh(<sc>iii</sc>)-catalyzed redox-neutral C–H/N–H/C–O bond activation is presented.