TRANSITION-METAL-SUBSTITUTED PHOSPHANES, ARSANES AND STIBANES, LXIII - COUPLING REACTIONS OF ALKYNES WITH IRON COORDINATED DIPHENYLPHOSPHANE - GENERATION OF AN ALKENYLPHOSPHANE AND A CHELATING BISPHOSPHANE LIGAND

The reaction of {Cp(OC)(2)[H(Ph)(2)P]Fe}BF4 (1) with acetylenedicarbox ylic acid dimethyl ester (2) in the presence of Et3N followed by addit ion of HBF4 leads to the cationic alkenylphosphane complex [Cp(OC)(2)F e-P(Ph)(2)-C(CO2Me)=C(CO2Me)H]BF4 (5). In contrast, the reaction of th e bis(diphenylphosphane) complex {Cp(OC)[H(Ph)(2)P](2)Fe}BF4 (6) with 2 yields p(OC)Fe[P(Ph)(2)-C(H)(CO2Me)-C(H)(CO2Me)-PPh2]}BF4 (7), beari ng a functionalised dppe-analogous chelate phosphane. The molecular st ructures of 5 and 7 are determined by single crystal X-ray analysis. ( C) 1998 Elsevier Science S.A. All rights reserved.