96348-97-9Relevant articles and documents
Synthesis and reactivity of [(thiomethoxy)methyl]- and [(dimethylsulfonio)methyl]nickel(II) complexes
Davidson, James G.,Barefield, E. Kent,Van Derveer, Donald G.
, p. 1178 - 1184 (2008/10/08)
The new complexes [NiCp(L)CH2SCH3] (L = PPh3, PPhMe2, P(OCH3)3 were prepared by substitution of halide in [NiCp(L)X] and, in the case of L = PPh3, by reaction of chloromethyl methyl sulfide with [Ni(PPh3)2(C2H4)], to give [Ni(PPh3)2(Cl)(η1-CH2SCH 3)] or [Ni(PPh3)(Cl)(η2-CH2SCH3)] depending upon reaction conditions, followed by reaction with sodium cyclopentadienide. Addition of ammonium hexafluorophosphate to [Ni(PPh3)2(Cl)(η1-CH2SCH 3)] in acetone produced [Ni(PPh3)2(η2-CH2SCH 3)]PF6. S-methylation of the cyclopentadienyl complexes yielded the sulfonium ions [NiCp(L)CH2S(CH3)2]+. [NiCp(PPh3)CH2S(CH3)2]+ was also prepared from [NiCp(L)X] and dimethylsulfonium methylide, but the dinuclear species {[NiCp(PPh3)CH2]2S(CH3)}+ was formed in comparable amounts. The structure of the dinuclear complex (PF6- salt, acetone solvate) was determined by a single-crystal X-ray structure: C52H53F6Ni2OP3S; space group Pbcm; a = 11.20 (1) A?, b = 18.814 (6) A?, c = 24.40 (1) A?; Z = 4; R = 0.11 and Rw = 0.096 for 2100 data with F > 3σF. The sulfur and methyl carbons of the cation lie on a mirror plane. The mononuclear sulfonium salts reacted with charged nucleophiles (X = Br-, I-, and CN-) to produce [NiCp(L)X]. That these reactions occurred by substitution of the CH2S(CH3)2 group was suggested by the fact that [NiCp(PPh3)CH2CN], prepared from the halide and LiCH2CN, was stable under the reaction conditions. The nickelated sulfonium salts were found to have limited utility as reagents for the cyclopropanation of cyclooctene in acetonitrile solution.
