Reactivity of carbon dioxide with n-butyl(phenoxy)-, (alkoxy)-, and (oxo)stannanes:: Insight into dimethyl carbonate synthesis
Reactivity of carbon dioxide with n-butyl(phenoxy)-, (alkoxy)-, and (oxo)stannanes:: Insight into dimethyl carbonate synthesis
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DOI：
10.1021/om000397f
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发表时间：
2000-10-30
期刊：
影响因子：
2.8
通讯作者：
Stutzmann, S
中科院分区：
文献类型：
--
作者：
Ballivet-Tkatchenko, D;Douteau, O;Stutzmann, S
本文研究了一系列丁基锡烷（苯氧基锡烷、烷氧基锡烷和氧代锡烷）在Sn-O键上的CO_2插入反应。三丁基衍生物Bu 3SnOR（2a，R = Me; 9a，R = Pr-1; 4a，R = Bu-t; 5a，R = SnBu 3）（1）定量地产生Bu 3Sn（OCO 2 R），2b-5 b;类似的三丁基苯氧基锡烷1，反应性较低。对于Bu_2Sn（OR）（2），OR（8a）中的Bu-t基团的空间效应抑制了常压下的碳酸化反应。在R = Me（6a）或R = Pr-1（7a）的情况下，仅一个Sn-OR键反应，产生Bu 2Sn（OR）（OCO 2 R）6 b或7 b。用2-丙醇处理6a在CO2下选择性地得到混合化合物Bu 2Sn（OMe）（（OCO 2 Pr）-Pr-i）。容易脱嵌CO2是所有化合物的共同特性，更容易发生在CO2系列中。在2b、5 b或6 b中的碳酸酯配体与MeI反应时化学计量转化为碳酸二甲酯（DMC）需要F-的亲核协助来进行：在MeOH的存在下，2b和5 b对于DMC的形成几乎是无活性的，与6 b相反。在超临界CO2-甲醇条件下，产率最高。
The CO2 insertion into Sn-O bonds of a series of butyl(phenoxy)-, (alkoxy)-, and (oxo)stannanes has been investigated. The tributyl derivatives Bu3SnOR (2a, R = Me; 9a, R = Pr-i; 4a, R = Bu-t; 5a, R = SnBu3)(1) give quantitatively Bu3Sn(OCO2R), 2b-5b; the analogous tributylphenoxystannane, 1, is less re active. For the dibutyl series, Bu2Sn(OR)(2), steric effects of Bu-t groups in OR (8a) suppress carbonation under atmospheric pressure. With R = Me (6a) or R = Pr-i (7a), only one Sn-OR bond reacts, resulting in Bu2Sn(OR)(OCO2R), 6b or 7b. Treating 6a with 2-propanol affords under CO2 the mixed compound Bu2Sn(OMe)((OCO2Pr)-Pr-i), selectively. Facile deinsertion of CO2 is a common property of all compounds, occurring more readily in the dibutyl series. The stoichiometric transformation of the carbonate ligand in 2b, 5b, or 6b to dimethyl carbonate (DMC) on reaction with MeI requires nucleophilic assistance by F- to proceed: In the presence of MeOH, 2b and 5b are almost inactive for DMC formation, in contrast with 6b. The best yield is obtained under supercritical CO2-methanol conditions.