Polymerization of Aryl Isocyanides Possessing Bulky Substituents at an ortho Position Initiated by Organorhodium Complexes

The organorhodium(I) complexes Rh(R)(nbd)(PPh 3 ) (R = Me 2 C 6 H 3, 2,4,6-Pr i 3 C 6 H 2, 2-PhC 6 H 4; nbd = 2,5-norbornadiene), prepared from the reaction of [Rh(nbd)Cl] 2 with PPh 3 and LiR, effectively initiate the polymerization of aryl isocyanides possessing bulky substituents at an ortho position in the presence of PPh 3 to provide polyisocyanides in good yields.