TRANSITION-METAL SUBSTITUTED ACYLPHOSPHAN ES AND PHOSPHAALKENES .19. SYNTHESIS AND STRUCTURE DETERMINATION OF ETES(ETA-5-C(5)ME(5))(CO)(2)M-PCH(E)-C(E)=C-NME(2) (M=FE,RU E=CO(2)ME, CN)

The metallo-phosphaalkenes (eta(5)-C(5)Me(5))(CO)(2)M-P=C(NR(2))(2) (4 a,b, 5) result from the reaction of the corresponding bromo compounds (eta(5)-C(5)Me(5))(CO)(2)MBr with Me(3)Si-P=C(NR(2))(2). The complexes 4a and 5a are cleanly converted into the 1-metallo-1,2-dihydrophosphe tes (eta(5)-C(5)Me(5))(CO)(2)M-PCH(E)-C(E)=C-NMe(2) (10 a-c) (M = Fe, Ru; E = CO(2)Me, CN) by treatment with equimolar amounts of dimethyl f umarate or fumarodinitrile, respectively. The products 4a, b, 5 and 10 a-c have been characterized by elemental analysis as well as by spect roscopic data (IR, H-1, C-13, P-31 NMR, MS). The molecular structures of 4a and 10 a have been determined by single crystal X-ray analysis.