Sequential protocol for C(sp)–H carboxylation with CO2: KOtBu-catalyzed C(sp)–H silylation and KOtBu-mediated carboxylation
作者:Bo Yu、Peng Yang、Xiang Gao、Zhenzhen Yang、Yanfei Zhao、Hongye Zhang、Zhimin Liu
DOI:10.1007/s11426-017-9163-2
日期:2018.4
protocol for C(sp)–Hcarboxylation by employing a metal-free C–H activation/catalytic silylation reaction in conjunction with KOtBu-mediated carboxylation with CO2 was established, in which KOtBu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO2. Importantly, the carboxylation further promotes
将CO 2掺入CH键中是一个重要而有趣的话题。在本文中,通过使用无金属的C–H活化/催化甲硅烷基化反应与KO t Bu介导的CO 2羧化反应建立了C(sp)–H羧化的顺序方案,其中KO t Bu催化末端的甲硅烷基化炔烃在低温下形成炔基硅烷,并同时与大气CO 2介导炔烃的羧化反应。重要的是,羧基化进一步促进了甲硅烷基化,这使得整个反应非常迅速地进行。此外,该方法简单易行,具有反应时间短,底物范围广,对官能团的耐受性强和反应条件温和的特点,在大多数情况下,提供了一系列相应的丙酸产物,收率很高。另外,它还允许通过使用13 CO 2方便地进行13 C标记。
CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO<sub>2</sub> at room temperature
作者:B. Yu、P. Yang、X. Gao、Z. Z. Yang、Y. F. Zhao、H. Y. Zhang、Z. M. Liu
DOI:10.1039/c7nj01779k
日期:——
A CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO2 in the presence of trimethylsilylacetylene was developed to give functionalized propiolic acid products at roomtemperature. A wide range of propiolic acids bearing functional groups was successfully obtained in good to excellent yields. Mechanistic studies demonstrate that in the carboxylation process the alkynylsilane
Carboxylation of terminal alkynes with CO<sub>2</sub> catalyzed by imidazolium-bridged bis(phenolato) rare-earth metal complexes
作者:Kai Shi、Chengrong Lu、Bei Zhao
DOI:10.1039/d2nj03130b
日期:——
imidazolium-bridged bis(phenolato) rare-earth metal complexes 1–5 were synthesized using a readily available bisphenoxy-functionalized imidazolium salt and the corresponding rare-earth metal precursors RE[N(SiMe3)2]3 [RE = Y (1), Yb (2), Sm (3), Nd (4), La(5)], which were well characterized by single crystal diffraction analysis, elemental analysis, and NMR for complexes 1 and 5. The complexes were successfully
使用现成的双苯氧基官能化咪唑盐和相应的稀土金属前体 RE[N(SiMe 3 ) 2 ] 3 [ RE = Y ( 1 )、Yb ( 2 )、Sm ( 3 )、Nd ( 4 )、La( 5 )],通过单晶衍射分析、元素分析和 NMR 对配合物1和5进行了很好的表征。该配合物成功应用于末端炔烃与CO 2的羧化反应,其中配合物1表现出最高的催化活性。在大气压下以优异的收率获得了多种不同的炔基羧酸。值得注意的是,在目前的催化体系中,以末端炔烃、CO 2和烷基溴化物为起始原料,通过一锅三组分反应顺利进行了进一步的酯化反应。在 1 bar 压力和 50 °C 下以中等至优异的产率获得了几种取代的炔丙基酯。