(Z)-1-methoxy-4(diphenylphosphino)but-1-ene-3-yne: A versatile synthon for unsymmetrically substituted (diphenylphosphino)diacetylene derivatives

An efficient synthesis of Ph2P-C equivalent to C-C equivalent to C-Li, 1, was found, starting from commercially available (Z)-1-methoxybut-1-ene-3-yne and its diphenylphosphino derivative 2. The lithio compound 1 was condensed with electrophiles to give Ph2P-C equivalent to C-C equivalent to C-Sigma (Sigma = SiR3, SnR3, B((NPr)-Pr-i)(2)) 3. Compound 2 was easily transformed into the phosphonium salt 6 and the phosphine oxide 7 using Mel and H2O2 respectively. Derivatives 3 (Z = SiMe3, SnMe3) are reactive at phosphorus and at the Sigma group; complexation with W(CO)(5)THF gave the expected derivatives W(CO)(5)Ph2P-C equivalent to C-C equivalent to C-Sigma (Sigma = SiMe3, SnMe3), 10, and in the case of Sigma = SnMe3, coupling reaction between Ph2P-C equivalent to-C-C equivalent to C-SnMe3, 3c, and (eta(5)-IC5H4)Mn(CO)(3) in the presence of PdCl2(CH3CN)(2) as a catalyst gave the complex 11, Ph2P-C equivalent to C-C equivalent to C-(eta(5)-C5H4)Mn(CO)(3).