Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand

Tungsten NArR alkylidene complexes have been prepared that contain the electron-withdrawing ArR groups 2,4,6-X3C6H2 (ArX3, X = Cl, Br), 2,6-Cl2-4-CF3C6H2 (ArCl2CF3), and 3,5-(CF3)2C6H3 (Ar(CF3)2). Reported complexes include W­(NArR)2Cl2(dme) (dme = 1,2-dimethoxyethane), W­(NArR)2(CH2CMe3)2, W­(NArR)­(CHCMe3)­(OTf)2(dme), and W­(NArR)­(CHCMe3)­(ODBMP)2 (DBMP = 4-Me-2,6-(CHPh2)­C6H2). The W­(NArR)­(CHCMe3)­(ODBMP)2 complexes were explored as initiators for the polymerization of 2,3-dicarbomethoxynorbornadiene (DCMNBD).