N-Butylpyrrolidone (NBP) as a non-toxic substitute for NMP in iron-catalyzed C(sp2)–C(sp3) cross-coupling of aryl chlorides

Although iron catalyzed cross-couplings show extraordinary promise in reducing the environmental impact of more toxic metals, one of the main challenges is the use of reprotoxic NMP (NMP = N -methylpyrrolidone) as the key ligand.