949030-64-2Relevant academic research and scientific papers
Three- and five-membered W/C/N metallacycles formed by incorporation of acetonitrile molecules into silyltungsten intermediates
Suzuki, Eiji,Komuro, Takashi,Okazaki, Masaaki,Tobita, Hiromi
, p. 4379 - 4382 (2007)
Treatment of Cp*(CO)2W(NCMe)Me (Cp* = η5-C5Me5) with HSiR3 (R = Et, p-Tol) afforded N-silylated η2-iminoacyl tungsten complexes Cp*(CO)2W{κ2(C,N)-C(Me)= N(SiR3)} (1a, R = Et; 1b, R = p-Tol). Analogous reactions in the presence of excess acetonitrile for a prolonged reaction time led to the formation of five-membered metallacycles Cp*(CO)2W{κ2(C,N)-C(Me)=N-C(Me) =N(H)} (2) and Cp*(CO)2W{κ2(C,N)-C(CH 2SiR3)=N-C(Me)=N(H)} (3, R = p-Tol) through a C-N coupling of nitrile molecules and migration of a silyl group.
(η3-α-Silabenzyl)tungsten complexes: An isolable intermediate for interconversion between a silylene complex and a silyl complex through 1,2-aryl migration
Suzuki, Eiji,Komuro, Takashi,Kanno, Yuto,Tobita, Hiromi
supporting information, p. 748 - 751 (2013/03/14)
η3-α-Silabenzyl complexes Cp W(CO)2{η 3(Si,C,C)-Si(p-Tol)2R} (1a, R = Me; 1b, R = p-Tol; Cp* = η5-C5Me5, p-Tol = p-tolyl), the first silicon analogues of η3-benzyl complexes, were synthesized by abstraction of DMAP (4-(dimethylamino)pyridine) with BPh3 either from (aryl)(DMAP·silylene)tungsten complexes 2a,b at room temperature or from (arylsilyl)(DMAP)tungsten complexes 3a,b under irradiation. Complex 1 was demonstrated to be a key intermediate for the interconversion between 2 and 3 and to serve as a synthetic equivalent for both base-free silylene complexes and coordinatively unsaturated silyl complexes.
Synthesis and characterization of -2 C,N-N -silyliminoacyl tungsten complexes Cp*(CO)2W{-2 C,N -C(R) - NsiR-3} [R = Me, Et, i -Pr, t -Bu; R'3 = (p -Tol) 2Me, (p -Tol)3, Et3; Cp* = - 5-C5Me5]: Thermally induced carbon-carbon bond cleavage of their iminoacyl ligands
Suzuki, Eiji,Komuro, Takashi,Kanno, Yuto,Okazaki, Masaaki,Tobita, Hiromi
, p. 1839 - 1848 (2010/06/19)
DMAP-stabilized (p-tolyl)(silylene) complexes Cp*(CO) 2W(p-Tol){-Si(p-Tol)R′-DMAP} [1a, R′ = Me; 1b, R′ = p-Tol; DMAP = 4-(dimethylamino)pyridine] reacted with excess nitrile RCN (R = Me, Et, i-Pr, t-Bu) in toluene to give k2C,N-N-silyliminoacyl tungsten complexes Cp*(CO)2W{k2C,N-C(R)-NSi(p-Tol) 2R′} (2a, R = Me, R′ = Me; 2b, R = Et, R′ = Me; 2c, R = i-Pr, R′ = Me; 2d, R = t-Bu, R′ = Me; 3a, R = Me, R′ = p-Tol; 3b, R = Et, R′ = p-Tol; 3c, R = i-Pr, R′ = p-Tol; 3d, R = t-Bu, R′ = p-Tol). This reaction proceeds through 1,2-migration of a p-tolyl group from a tungsten center to a silylene ligand. Complexes 3a and 3b and similar complexes Cp*(CO)2W{-2C,N-C(R)- NSiEt3} (4a, R = Me; 4b, R = Et) were also synthesized by reactions of methyl(nitrile) complexes Cp*(CO)2W(NCR)Me (A, R = Me; B, R = Et) with hydrosilanes HSiR′3 (R′ = p-Tol, Et). A kinetic study on the dynamic process of 2c involving inversion of the chiral tungsten center reveals that the inversion can occur via dissociation of the iminoacyl nitrogen atom coordinating to the tungsten center. Thermal reaction of a toluene solution of N-silyliminoacyl complexes 3a and 3b at 120 °C in a sealed tube gave a cis/trans mixture of alkyl(silylisocyanide) complexes cis/trans-Cp*(CO)2W(R){CNSi(p-Tol)3} (5a, R = Me; 5b, R = Et) through cleavage of the C-C bond between the iminoacyl carbon and the alkyl substituent R in 3a or 3b. The molecular structures of 3b and cis-5b were determined by X-ray crystallography.
