Preparation and reactions of tantalum alkylidene complexes containing bulky phenoxide or thiolate ligands. Controlling ring-opening metathesis polymerization activity and mechanism through choice of anionic ligand
Preparation and reactions of tantalum alkylidene complexes containing bulky phenoxide or thiolate ligands. Controlling ring-opening metathesis polymerization activity and mechanism through choice of anionic ligand
复制标题
含有大酚盐或硫醇盐配体的亚烷基钽配合物的制备和反应。
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
R. Schrock
中科院分区：
文献类型：
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作者：
Kevin C. Wallace;A. Liu;J. C. Dewan;R. Schrock
在Ta(CH-t-Bu)(THF){sub 2}Cl{sub 3}中加入LiDIPP = o -2,6- c {sub 6}H{sub 3}-i-Pr{sub 2}可以高产得Ta(CH-t-Bu)(DIPP){sub 3}(THF)(1)。可以用类似的方法制备Ta(CH-t-Bu)(DMP){sub 3}(THF) （3; DMP = o -2,6- c {sub 6}H{sub 3}Me{sub 2}）和Ta(CH-t-Bu)(TIPT){sub 3}(THF) （5; TIPT = S-,2,4,6- c {sub 6}H{sub 2}i-Pr{sub 3}）。1与1等量苯乙烯迅速反应生成钽环丁烷配合物Ta(CH(Ph)CH(t-Bu)CH{sub 2})(DIPP){sub 3}。报道了该配合物的晶体结构和分子结构。1和乙烯基三甲基硅烷之间的类似反应得到Ta(CHSiMe{sub 3})(DIPP){sub 3}（THF）或Ta(CH(SiMe{sub 3})CH(SiMe{sub 3})CH{sub 2})(DIPP){sub 3}，具体取决于反应条件；两者处于平衡状态。1与乙烯反应平稳，产率高，得到Ta(CH{sub 2}CH{sub 2}CH{sub 2})(DIPP){sub 3}，但1与丙烯或1-丁烯等烯烃处理后，没有得到任何可表征的物质。向1中加入过量的顺-2-戊烯会导致快速的转化（在15分钟内达到平衡的100当量），但活性是短暂的。与1与烯烃的反应相反，Ta(CH-t-Bu)(TIPT){sub 3}（THF）不与普通烯烃反应，也不会将它们合成。含有DIPP配体的钽环丁烷配合物与羰基官能性反应，根据羰基化合物、钽环和温度的不同，产生插入化学（氧化钽环己烷配合物）和维蒂格样反应性的混合物。1与降冰片烯反应生成可分离的钽环丁烷配合物Ta(CH(C{sub 5}H{sub 8})CHCH(t-Bu))(DIPP){sub 3}，其晶体结构已报道。参考文献25篇，图9张，表7张。«少
Addition of LiDIPP = O-2,6-C{sub 6}H{sub 3}-i-Pr{sub 2} to Ta(CH-t-Bu)(THF){sub 2}Cl{sub 3} yields Ta(CH-t-Bu)(DIPP){sub 3}(THF) (1) in high yield. Ta(CH-t-Bu)(DMP){sub 3}(THF) (3; DMP = O-2,6-C{sub 6}H{sub 3}Me{sub 2}) and Ta(CH-t-Bu)(TIPT){sub 3}(THF) (5; TIPT = S-,2,4,6-C{sub 6}H{sub 2}i-Pr{sub 3}) can be prepared by analogous methods. 1 reacts rapidly with 1 equiv of styrene to give the tantalacyclobutane complex Ta(CH(Ph)CH(t-Bu)CH{sub 2})(DIPP){sub 3}. The crystal and molecular structure of the complex are reported. An analogous reaction between 1 and vinyltrimethylsilane gives Ta(CHSiMe{sub 3})(DIPP){sub 3}(THF) or Ta(CH(SiMe{sub 3})CH(SiMe{sub 3})CH{sub 2})(DIPP){sub 3} depending upon reaction conditions; the two are in ready equilibrium. 1 reacts smoothly with ethylene to give Ta(CH{sub 2}CH{sub 2}CH{sub 2})(DIPP){sub 3} in high yield, but treatment of 1 with olefins such as propylene or 1-butene did not lead to any characterizable species. Addition of excess cis-2-pentene to 1 results in rapid metathesis (100 equiv to equilibrium in < 15 min), but activity is short-lived. In contrast to reactions between 1 and olefins, Ta(CH-t-Bu)(TIPT){sub 3}(THF) does not react with ordinary olefins and will not metathesize them. Tantalacyclobutane complexes containing the DIPP ligand react with the carbonyl functionality to give a mixture of insertion chemistry (oxytantalacyclohexane complexes) and Wittig-like reactivity, depending upon the carbonylmore » compound, the tantalacycle, and the temperature. 1 reacts with norbornene to give an isolable tantalacyclobutane complex, Ta(CH(C{sub 5}H{sub 8})CHCH(t-Bu))(DIPP){sub 3}, whose crystal structure is reported. 25 references, 9 figures, 7 tables.« less