TY - JOUR
T1 - Synthesis and characterization of dmap-stabilized aryl(silylene) complexes and (arylsilyl)(dmap) complexes of tungsten mechanistic study on the interconversion between these complexes via 1,2-aryl migration
AU - Suzuki, Eiji
AU - Komuro, Takashi
AU - Okazaki, Masaaki
AU - Tobita, Hiromi
PY - 2009/3/23
Y1 - 2009/3/23
N2 - Photoreaction of a mixture of Cp*(CO)3WMe (Cp* = η5-C5Me5) and HSiR2Ar [R 2Ar = Me2Ph, Me2(p-Tol), Me(p-Tol)2, and (p-Tol)2] in the presence of 4-(dimethylamino)pyridine (DMAP) gave DMAP-stabilized aryl(silylene) complexes Cp*(CO)2W(Ar)(= SiR2-DMAP) [la, R = Me, Ar = Ph; lb, R = Me, Ar = p-Tol; lc, R2 = Me(p-Tol), Ar = p-Tol; Id, R = Ar = p-Tol] via 1,2-migration of the aryl group from a silyl ligand to a tungsten center. Thermal reactions of Cp*(CO)2W(DMAP)Me (2) with HSiR2Ar at room temperature also gave la - d, and in all cases the yields were higher than those in the photoreaction. Silylene complexes la - d easily isomerized to arylsilyl complexes Cp*(CO)2- W(DMAP)(SiR2Ar) [3a, R = Me, Ar = Ph; 3b, R = Me, Ar = p-Tol; 3c, R, = Me(p-Tol), Ar = p-Tol; 3d, R = Ar = p-Tol] at 40-55 °C. On the other hand, irradiation of arylsilyl complexes 3a - d reproduced silylene complexes la - d, implying that the 1,2-aryl-migration between tungsten and silicon is reversible. The molecular structures of lc, 2, 3a, and 3d were determined by X-ray crystallography. A kinetic study on the 1,2-aryl-migration in the thermal isomerization from la - d to 3a - d suggests that the rate-determining step involves dissociation of DMAP from la - d.
AB - Photoreaction of a mixture of Cp*(CO)3WMe (Cp* = η5-C5Me5) and HSiR2Ar [R 2Ar = Me2Ph, Me2(p-Tol), Me(p-Tol)2, and (p-Tol)2] in the presence of 4-(dimethylamino)pyridine (DMAP) gave DMAP-stabilized aryl(silylene) complexes Cp*(CO)2W(Ar)(= SiR2-DMAP) [la, R = Me, Ar = Ph; lb, R = Me, Ar = p-Tol; lc, R2 = Me(p-Tol), Ar = p-Tol; Id, R = Ar = p-Tol] via 1,2-migration of the aryl group from a silyl ligand to a tungsten center. Thermal reactions of Cp*(CO)2W(DMAP)Me (2) with HSiR2Ar at room temperature also gave la - d, and in all cases the yields were higher than those in the photoreaction. Silylene complexes la - d easily isomerized to arylsilyl complexes Cp*(CO)2- W(DMAP)(SiR2Ar) [3a, R = Me, Ar = Ph; 3b, R = Me, Ar = p-Tol; 3c, R, = Me(p-Tol), Ar = p-Tol; 3d, R = Ar = p-Tol] at 40-55 °C. On the other hand, irradiation of arylsilyl complexes 3a - d reproduced silylene complexes la - d, implying that the 1,2-aryl-migration between tungsten and silicon is reversible. The molecular structures of lc, 2, 3a, and 3d were determined by X-ray crystallography. A kinetic study on the 1,2-aryl-migration in the thermal isomerization from la - d to 3a - d suggests that the rate-determining step involves dissociation of DMAP from la - d.
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U2 - 10.1021/om801140d
DO - 10.1021/om801140d
M3 - Article
AN - SCOPUS:64549150466
VL - 28
SP - 1791
EP - 1799
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 6
ER -