GoKawiilRhodium catalyst inserts single carbon atom to build spirocyclic C–C bonds
Researchers developed a rhodium-catalysed reaction that inserts one carbon atom into C–C sigma bonds of biphenylene molecules, forming four new C–C bonds around a single spiro carbon center. The method uses N-isocyanoiminophosphorane as a carbon-atom source and works for both identical and different biphenylene partners, as well as reactions mixing sigma- and pi-bond activation.