Unsaturated alkylidyne ligands bearing a terminal isocyanide functionalityand intervening ethynylbenzene groups

The synthesis of complexes 2 [W(CC6H4(CCC6H4NH2-4)-4)Cl(CO)(2)(dppe)], and 4 [W(CC6H4(CCC6H4(CCC(6)H(2)iPr(2)-3,5-NHCHO-4)-4)-4)Cl(CO)(2)(dppe)], was achieved by Pd(II) catalyzed cross-coupling reactions of complex 1 [W(CC6H4 I-4)Cl(CO)(2)(dppe)], with the respective aromatic acetylenes. Formylation of complex 2 with acetic formic anhydride affords the formamide 3 [W(CC6H4( CCC6H4NHCHO-4)-4)Cl(CO)(2)(dppe)]. The isocyanide derivatives 5 [W(CC6H4(CC C6H4NC-4)-4)Cl(CO)(2)(dppe)], and 6 [W(CC6H4(CCC6H4(CCC(6)H(2)iPr(2)-3,5-NC -4)-4)-4)Cl(CO)(2)(dppe)], were obtained by dehydration of complexes 3 and 4 with triphosgene/NEt3. (C) 1999 Elsevier Science S.A. All rights reserved .