Stereochemistry of Disilanylene-Containing Cyclic Compounds. Thermal reactions of cis- and trans-3,4-Benzo-1,2-diisopropyl-1,2-dimethyl-1,2-disilacyclobut-3-ene
Stereochemistry of Disilanylene-Containing Cyclic Compounds. Thermal reactions of cis- and trans-3,4-Benzo-1,2-diisopropyl-1,2-dimethyl-1,2-disilacyclobut-3-ene
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含二硅烷基环状化合物的立体化学。
DOI：
10.1021/om400824p
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发表时间：
2013
期刊：
影响因子：
2.8
通讯作者：
Tokio Yamabe
中科院分区：
文献类型：
--
作者：
Akinobu Naka;Junnai Ikadai;Jun Sakata;Mitsuo Ishikawa;Yoshihiro Hayashi;Liudmil Antonov;Susumu Kawauchi;Tokio Yamabe
顺式-3，4-苯并-1，2-二异丙基-1，2-二甲基-1，2-二硅杂环丁-3-烯（1a）与叔丁醇在300 °C下热反应24 h，以71%的产率高立体专一性地得到了异丙基-1-（叔丁氧基异丙基甲基硅基）-2-（异丙基甲基硅基）苯（2a）。反式苯并二硅杂环丁烯（1b）与叔丁醇进行类似的反应，得到苏式异构体2，产率为81%，为唯一产物。在叔丁醇存在下，1a，b的光解反应得到了1-[2-（异丙基甲基硅基）苯基]-1-异丙基硅烯与叔丁醇反应生成的两种加合物的混合物。1a与乙烯在高压釜中于300 °C反应24 h，得到3，4，9，10-二苯并（r-1）-反式-2，trans_5，cis-8-四异丙基-1，2，5，8-四硅杂环十二碳-3，9-二烯（10a），为单一立体异构体，产率为71%。然而，1b与乙烯在相同条件下的反应产生聚[1，2-双（异丙基甲基亚甲硅烷基）亚苯基-乙烯]，相对于聚苯乙烯标准物，其分子量测定为61000（Mw/Mn= 2.32）。1a与1-己炔、叔丁基乙炔、苯乙炔和（三甲基甲硅烷基）乙炔在苯中于150或200 °C在密封的脱气管中进行立体特异性反应，以高产率分别得到作为唯一产物的顺-5，6-苯并-1，4-二异丙基-1，4-二甲基-1，4-二硅杂环己-2，5-二烯衍生物（11 a-14 a）。1b与炔在相同条件下反应，高产率地得到了反式苯并二硅杂环己二烯（11b-14 b）。对3，4-苯并-1，1，2，2-四甲基-1，2-二硅杂环丁-3-烯（1c）与叔丁醇和乙炔反应的理论处理表明，底物直接与1c反应生成相应的加合物。对于1c与乙炔的反应，已经表明乙炔分子直接插入到1c中的硅-硅键中，得到苯并二硅杂环己二烯体系。这种直接反应的基板与1c被证明是积极更有利的比ofo-醌乙硅烷，1，2-双（二甲基亚硅基）环己-3，5-二烯，所产生的共旋开环反应的1c与基板。
The thermal reaction ofcis-3,4-benzo-1,2-diisopropyl-1,2-dimethyl-1,2-disilacyclobut-3-ene (1a) withtert-butyl alcohol at 300 °C for 24 h proceeded with high stereospecificity to giveerythro-1-(tert-butoxyisopropylmethylsilyl)-2-(isopropylmethylsilyl)benzene (2a) in 71% yield, as a single stereoisomer. A similar reaction oftrans-benzodisilacyclobutene (1b) withtert-butyl alcohol produced thethreoisomer2bin 81% yield, as the sole product. The photolysis of1a,bin the presence oftert-butyl alcohol afforded a mixture of two adducts formed by the reaction of 1-[2-(isopropylmethylsilyl)phenyl]-1-isopropylsilene withtert-butyl alcohol, respectively. The reaction of1awith ethylene in an autoclave at 300 °C for 24 h gave 3,4,9,10-dibenzo(r-1)-trans-2,trans-5,cis-8-tetraisopropyl-1,2,5,8-tetrasilacyclododeca-3,9-diene (10a), as a single stereoisomer in 71% yield. The reaction of1bwith ethylene under the same conditions, however, produced poly[1,2-bis(isopropylmethylsilylene)phenylene–ethylene], whose molecular weight was determined to be 61000 (Mw/Mn= 2.32), relative to polystyrene standards. The reaction of1awith 1-hexyne,tert-butylacetylene, phenylacetylene, and (trimethylsilyl)acetylene in benzene in a sealed degassed tube at 150 or 200 °C proceeded stereospecifically to give the respectivecis-5,6-benzo-1,4-diisopropyl-1,4-dimethyl-1,4-disilacyclohexa-2,5-diene derivatives (11a–14a) in high yields as the sole products. The reaction of1bwith the alkynes under the same conditions afforded the respectivetrans-benzodisilacyclohexadienes (11b–14b), as the sole stereoisomers in high yields. Theoretical treatment for the reaction of 3,4-benzo-1,1,2,2-tetramethyl-1,2-disilacyclobut-3-ene (1c) withtert-butyl alcohol and acetylene indicated that the substrates react directly with1cto give the respective adducts. For the reaction of1cwith acetylene, it has been shown that the acetylene molecule inserts directly into a silicon–silicon bond in1cto give the benzodisilacyclohexadiene system. Such direct reactions of the substrates with1cwere shown to be energetically more advantageous than the reaction ofo-quinodisilane, 1,2-bis(dimethylsilylene)cyclohexa-3,5-diene, arising from a conrotatory ring-opening reaction of1cwith substrates.