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
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
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DOI：
10.1021/om801140d
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发表时间：
2009-02
期刊：
影响因子：
2.8
通讯作者：
E. Suzuki;Takashi Komuro;M. Okazaki;H. Tobita
中科院分区：
文献类型：
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作者：
E. Suzuki;Takashi Komuro;M. Okazaki;H. Tobita
Cp*(CO)3WMe （Cp* = η - 5- c5me5）和HSiR2Ar [R2Ar = Me2Ph, Me2(p-Tol), Me(p-Tol)2和（p-Tol）3]混合物在4-（二甲氨基）吡啶（DMAP）存在下光化学反应得到DMAP稳定的芳基（硅烯）配合物Cp*(CO)2W(Ar)(= SiR2·DMAP) [1a, R = Me, Ar = Ph；b, R = Me, Ar = p-Tol；1c, R2 = Me(p-Tol), Ar = p-Tol；[d, R = Ar = p-Tol]通过芳基从硅基配体到钨中心的1,2-迁移。Cp*(CO)2W(DMAP)Me(2)与HSiR2Ar在室温下热反应的产率也为1a−d，且均高于光反应产率。硅烯配合物1a−d容易异构化为芳基硅基配合物Cp*(CO)2W(DMAP)(SiR2Ar) [3a, R = Me, Ar = Ph；3b, R = Me, Ar = p-Tol；3c, R2 = Me(p-Tol), Ar = p-Tol；3d, R = Ar = p-Tol]，温度为40 ~ 55℃。另一方面，照射芳基硅基配合物3a−d可再生硅基配合物1a−d，表明1,2-芳基在钨和硅之间的迁移是可逆的。测定了1c、2、3a和3d的分子结构。
Photoreaction of a mixture of Cp*(CO)3WMe (Cp* = η5-C5Me5) and HSiR2Ar [R2Ar = Me2Ph, Me2(p-Tol), Me(p-Tol)2, and (p-Tol)3] in the presence of 4-(dimethylamino)pyridine (DMAP) gave DMAP-stabilized aryl(silylene) complexes Cp*(CO)2W(Ar)(═SiR2·DMAP) [1a, R = Me, Ar = Ph; 1b, R = Me, Ar = p-Tol; 1c, R2 = Me(p-Tol), Ar = p-Tol; 1d, 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 1a−d, and in all cases the yields were higher than those in the photoreaction. Silylene complexes 1a−d easily isomerized to arylsilyl complexes Cp*(CO)2W(DMAP)(SiR2Ar) [3a, R = Me, Ar = Ph; 3b, R = Me, Ar = p-Tol; 3c, R2 = 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 1a−d, implying that the 1,2-aryl-migration between tungsten and silicon is reversible. The molecular structures of 1c, 2, 3a, and 3d were dete...