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首页> 外文期刊>Bulletin of the Chemical Society of Japan >Organic Syntheses Utilizing Titanium Carbene Complexes
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Organic Syntheses Utilizing Titanium Carbene Complexes

机译：利用钛碳配合物的有机合成

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摘要

Synthetic reactions utilizing titanium carbene complexes prepared by the desulfurizative titanation of thioacetals and related organosulfur compounds with the titanocene(II)species [Cp_2Ti{P(OEt)_3}_2] are described.The Wittig type olefination of carbonyl compounds including carboxylic acid derivatives with the titanium carbene complexes affords a variety of olefinic compounds.The reaction is successfully applied to the intramolecular carbonyl olefination of carboxylic acid derivatives,giving various carbo-and hetero-cycles.The organotitanium species generated by the treatment of gem-dihalides and certain alkyl halides with the titanocene(II)species are also useful for the transformation of carbonyl compounds into highly substituted olefins or into olefins bearing a bulky substituent.The alkylidenetitanocenes generated from thioacetals react with olefins in both inter-and intramolecular fashions to give olefin metathesis products.The ring-closing olefin metathesis of the carbene complexes formed from thioacetals having a terminal olefin provides a variety of unsaturated heterocyclic compounds.On the other hand,cyclopropanation proceeds when terminal olefins are treated with alkenyl-and alkynyl-carbene complexes.Cyclopropanes are also obtained by treatment of gem-dihalides having a terminal carbon-carbon double bond.The carbene complexes are also highly reactive toward triple bonds.Their reactions with nitriles afford the acyl-ation products after hydrolysis of intermediary titanium vinylimido complexes.The reactions of the carbene complexes with internal alkynes via the formation of titanacyclobutene intermediates afford conjugated dienes with high stereose-lectivity,whereas metathesis polymerization proceeds to give trans-poly acetylene when the carbene complexes are treated with excess acetylene.The carbene complexes also react with t-alkyl halides and group 14 metal hydrides.
机译：描述了利用硫代乙缩醛和相关的有机硫化合物与钛茂（II）物种[Cp_2Ti {P（OEt）_3} _2]的脱硫钛化反应制备的钛卡宾配合物的合成反应。包括羧酸衍生物在内的羰基化合物的Wittig型烯化反应钛卡宾配合物可提供多种烯烃化合物。该反应已成功应用于羧酸衍生物的分子内羰基烯化反应，产生了各种碳环和杂环。通过处理宝石二卤化物和某些烷基卤化物生成的有机钛物种钛茂（II）物种也可用于将羰基化合物转化为高度取代的烯烃或带有庞大取代基的烯烃。由硫缩醛生成的烷基亚氨基钛烯以分子内和分子内方式与烯烃反应生成烯烃复分解产物。卡宾化合物的闭环烯烃复分解由具有末端烯烃的硫缩醛形成的杂环化合物可提供各种不饱和杂环化合物。另一方面，当末端烯烃用链烯基和炔基-卡宾配合物处理时，环丙烷化会进行。环丙烷也可通过处理具有末端烯烃的二卤化物获得碳-碳双键。卡宾配合物对三键也具有高反应性。它们与腈的反应在中间钛乙烯基亚胺基配合物水解后提供了酰基化产物。卡宾配合物与内部炔烃的反应是通过钛环丁烯中间体的形成可以得到具有高立体选择性的共轭二烯，而当用过量的乙炔处理卡宾配合物时，复分解聚合反应进行以得到反式聚乙炔。卡宾配合物还与叔烷基卤化物和第14族金属氢化物反应。

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