Reaction Design of Medium-sized Ring Structure Based on the Working Hypothesis of Ethereal Oxonium Ylide Formation

基于以太氧叶立德形成工作假说的中型环结构反应设计

基本信息

批准号：
08455416
负责人：
OKU Akira
金额：
$ 4.93万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455416/
关键词：
carbene carbenoid oxonium ylide cyclic ether cyclic acetal cyclic orthoester ring-enlargement alkenyloxyketene 環状エーテル

项目摘要

The ambiphilicity of cerbene-type molecules can be inherited in the form of onium ylides. While ethereal oxonium ylides still continue to elude spectroscopic identification, their formations have been demonstrated indirectly by kinetic measurements, e.g., in the reaction of (biphenyl-4-yl) chlorocarbene with THF.On this basis, we designed novel ring-expansion reactions via bi-and tricyclic oxonium ylides for synthesis.Bicyclooxonium ylides formed in the Rh-catalyzed reaction of diazoketones tethered to five-to eight-membered cyclic ethers, where the tethering chains are one methylene units, underwent a novel three-carbon ring-enlargement reaction to form effectively the corresponding eight-to eleven-membered cyclic ketoethers, respectively. Diazoketones tethered to five-to eight-membered cyclic acetals, where the tethering chains are one or two methylene units, also underwent the similar enlargement reaction. Not only rhodium ketocarbenoids but also free carbenes such as alkylidenecarb … More enes bearing cyclic ethers or acetals behaved similarly to give cyclic dienol ethers. In all the reactions, key intermediates are bicyclooxonium ylides whose reactivity is controlled by the stability of charges and ring-strain.The reaction of bicyclic orthoester bearing a diazocarbonyl function tethered by one methylene unit produced a 9-membered polyoxygenated cyclic ether quantitatively. The enlargement efficiency is not attenuated when the tethering methylene chain is elongated from one to four. This indicates that the formation of tricyclooxonium ylides and their ring-expansion are highly favored by not only the enolate-stabilization but also the presence of three ethereal oxygen atoms in orthoesters which delocalize the positive charge of the ylides to facilitate the formation of ring-enlarged zwitterion (1, n-ambiphile) structure.In addition to the ring-expansion reaction, it was unveiled that oxonium ylides of cyclic ethers show an effective novel ring-opening rearrangement reaction leading to the formation of alkenyloxyketenes known as highly reactive transient species. Less

cerbene型分子的抗胆汁性可以遗传为Ylides的形式。虽然Ylides的空中氧氧仍然继续洗脱光谱鉴定，但它们的形成已通过运动测量进行间接证明，例如，在此基础上（Biphenyl-4-4-基）氯卡苯氯与Thf.on的反应中，我们设计了通过Bi-and-Tricyclic yeloxen yloxen yloxensysementerysementerysementerysementerysementerysementerysementerysementerysementy.biderice ylixensy insclide。重为重氮蛋白酶的Rh催化反应被束缚至五到八元的环状醚，绑带链是一个甲基单元，进行了一种新型的三碳环环反应，有效地形成了相应的八到相应的八到元素的环境循环酮埃瑟体，在该反应中是一个或两种甲基元素，同时是甲基元素，同时又有两个甲基元素。不仅酮酮苯二酚，而且还有诸如烷基肾上腺素等游离的碳纤维……更多的带有环状醚或乙烯的ENES的行为相似，以产生环状二烯二烯。在所有反应中，关键的中间体都是生物氧基氧基，其反应性受电荷和环晶的稳定性的控制。生物矫正器的反应具有一个由一个甲基单元支撑的重18Zocarbonyl功能，从而产生了9-MERGER的多氧环纤维醚。当绑扎亚甲基链从1到四个伸长时，增强效率不会衰减。 This indicates that the formation of tricyclooxonium ylides and their ring-expansion are highly favored by not only the enolate-stabilization but also the presence of three ethereal oxygen atoms in orthoesters which delocalize the positive charge of the ylides to facilitate the formation of ring-enlarged zwitterion (1, n-ambiphile) structure.In addition to the ring-expansion reaction, it was unveiled循环醚的氧含量显示出一种有效的新型开环的重排反应，导致形成被称为高反应性瞬态物种的烯烃形成。较少的