Olefin Hydrosilylation Catalysts Based on Allyl Bis(phenolato) Complexes of the Early Lanthanides
Olefin Hydrosilylation Catalysts Based on Allyl Bis(phenolato) Complexes of the Early Lanthanides
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DOI：
10.1002/asia.201000598
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发表时间：
2011-02-01
影响因子：
4.1
通讯作者：
Okuda, Jun
中科院分区：
文献类型：
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作者：
Abinet, Elise;Spaniol, Thomas P.;Okuda, Jun
烯烃硅氢加成反应通常由铂化合物催化，如Speier[1a]或Karsted催化剂。[1B]均相后过渡金属(Co，Rh，Pd，Pt)催化剂在活性、区域选择性和立体选择性方面得到了广泛的优化。[1C]稀土配合物也被认为能有效地催化烯烃硅氢加成反应。[2]它们的催化活性随着中心金属的大小而增加，因为关键步骤涉及S键的歧化反应。因此，文献中除了普遍存在的茂金属骨架以外的惰性辅助配体并不是很多。[2，3]不久前，含有两个硬阴离子氧给体和一个软硫醚部分的硫键连接的双(苯酚)配体支架被引入，这些支架可以根据其空间体积进行广泛的修饰。[4a-c]这些支架允许开发高效的Group4金属催化剂，用于苯乙烯的立体选择性聚合[4d-f]，也可以有效地支撑更大的稀土中心原子，如单体[SmACHTUNGRENUNG(TbMP)ACHTGUNGRENUNG(OAr)ACHTGTRENUNG(THF)][5]6‘-硫代二(2-叔丁基-4-甲基苯酚)和硅酰胺钪的络合物，
Olefin hydrosilylation is commonly catalyzed by platinum compounds, such as the Speier [1a] or Karsted catalysts.[1b] Homogeneous late-transition-metal (Co, Rh, Pd, Pt) catalysts have been extensively optimized with respect to activity, regioselectivity, and stereoselectivity.[1c] Lanthanide complexes are also known to efficiently catalyze the hydrosilylation of olefins.[2] Their catalytic activity increases with the size of the central metal, as the crucial steps involve s-bond metathesis. Therefore, inert ancillary ligands other than the ubiquitous metallocene frameworks are not numerous in the literature.[2, 3]Some time ago, sulfur-linked bis (phenolato) ligand scaffolds that contain two hard anionic oxygen donors along with a soft thioether moiety were introduced, and these scaffolds can be broadly modified in terms of their steric bulk.[4a–c] These scaffolds have allowed the development of efficient Group4 metal catalysts for the stereoselective polymerization of styrene,[4d–f] and are also effective for supporting larger lanthanide central atoms, such as monomeric [SmACHTUNGTRENNUNG (tbmp) ACHTUNGTRENNUNG (OAr) ACHTUNGTRENNUNG (thf)][5](tbmp= 6, 6’-thiobis (2-tert-butyl-4-methylphenolate)) and silylamido complexes of scandium,