Rh(III)-Catalyzed synthesis of pyrazolo[1,2-a] cinnolines from pyrazolidinones and diazo compounds

Rhodium(iii)-catalyzed redox-neutral annulation of pyrazolidinones with diazo compounds has been described. This reaction provides a straightforward platform to access various pyrazolo[1,2-a]cinnolines, which have potential medicinal value, under mild reaction conditions, with good regioselectivity and high functional group tolerability.