Allylnickel(II) and Allylpalladium(II) Derivatives of [(2-(Diphenylphosphino)ethyl)cyclopentadienyl]tricarbonylmetalates: Reactions with Free Radicals

作者：Fischer Paul J^*; Neary Michelle C; Heerboth Aaron P; Sullivan Kevin P

来源：Organometallics, 2010, 29(20): 4562-4568.

DOI：10.1021/om1006825

The emerging utility of the bridging (2-(diphenylphosphino)ethyl)cyclopentadienyl (CpPPh) ligand to kinetically stabilize early-late metal metal bonds to facilitate novel reactions in heterobimetallics is further established by the syntheses of four-legged piano stool M'{M(eta(3)-L)}(CO)(3)(mu-eta(5):eta(1)-Cp(PPh)) (M' = Cr, Mo, W; M = Ni, Pd; L = allyl, 2-methylallyl, cyclohexenyl). Complexes 1-3 (M = Ni, L = allyl) and 4-6 (M = Ni, L = 2-methylallyl) are the first structurally characterized heterobimetallics with transition metal Ni(eta(3)-allyl) units, while 7-9 (M = Ni, L = cyclohexenyl) are the only structurally characterized transition metal-Ni(eta(3)-cyclohexenyl) complexes. Like Pd(eta(3)-allyl)Cl(PPh(3)), 1-3 and 10-12 (M = Pd, L = ally!) respectively provide 4,4,4-triphenyl-1-butene as the sole allyl ligand coupling product from competitive reactions of phenyl and trityl radicals. However, while phenyl radical attack at the Pd(II) of Pd(eta(3)-allyl)Cl(PPh(3)) is proposed as the first step in the trityl radical allyl ligand coupling reaction, direct trityl radical attack at eta(3)-allyl is strongly suggested in 1-3 and 10-12, respectively. A modest heterobimetallic effect may render the chromium complexes 1 and 10 more reactive with trityl radical than the tungsten complexes 3 and 12.

• 出版日期2010-10-25