S-Methylidene Agents: Preparation of Chiral Non-Racemic Heterocycles.
S-Methylidene Agents: Preparation of Chiral Non-Racemic Heterocycles.
复制标题
DOI：
10.1016/j.tet.2008.10.019
复制
发表时间：
2009-01-03
期刊：
影响因子：
2.1
通讯作者：
Standen MC
中科院分区：
文献类型：
--
作者：
Forbes DC;Bettigeri SV;Patrawala SA;Pischek SC;Standen MC
硫叶立德与醛、亚胺和酮官能团的反应以优异的产率提供所需的三元杂环。硫叶立德在羧甲基锍甜菜碱官能团脱羧后原位产生。在所调查的七种羧甲基锍甜菜碱衍生物中，获得了具有结合到硫代乙酸酯衍生物的S-甲基和S-苯基官能团的π-受体向杂环的最高水平的转化。涉及羧甲基锍甜菜碱官能团的脱羧的亚甲基氮丙啶化和环氧化补充了现有技术，具有反应方案、转化水平和范围的优点。虽然在亚胺官能团的氮丙啶化中观察到中等水平的非对映体控制，但使用Jacobsen的Co（II）-salen络合物以高产率和对映体选择性获得了四种环氧乙烷。分离的手性非外消旋环氧乙烷构成分别从3-溴-4-甲氧基苯甲醛和3，4，5-三甲氧基苯甲醛开始的龟苷-B和考布他汀的正式合成。
Reaction of sulfur ylide with aldehyde, imine, and ketone functionality affords the desired three-membered heterocycle in excellent yield. The sulfur ylide is generated in situ upon decarboxylation of carboxymethylsulfonium betaine functionality. Of the seven carboxymethylsulfonium betaine derivatives surveyed, the highest level of conversion of π-acceptor to heterocycle was obtained having S-methyl and S-phenyl functionality bound to a thioacetate derivative. Methylene aziridinations and epoxidations involving the decarboxylation of carboxymethylsulfonium betaine functionality complements existing technologies with the advantages of the reaction protocol, levels of conversion and scope. While moderate levels of diastereocontrol were observed in the aziridination of imine functionality, the four oxiranes resolved using Jacobsen’s Co(II)-salen complex were obtained in both high yield and enantioselectivity. The isolated chiral non-racemic oxiranes constitute the formal synthesis of chelonin-B and combretastatin starting from 3-bromo-4-methoxybenzaldehyde and 3,4,5-trimethoxybenzaldehyde respectively.
登录
查看更多内容
影响因子：
2.1
作者：
Ciaccio, JA;Drahus, AL;Geneste, R
通讯作者：
Geneste, R
影响因子：
3.6
作者：
Forbes, David C.;Amin, Sejal R.;Standen, Michael C.
通讯作者：
Standen, Michael C.
影响因子：
5.2
作者：
Forbes, DC;Standen, MC;Lewis, DL
通讯作者：
Lewis, DL
影响因子：
2.1
作者：
BOUDA, H;BORREDON, ME;GASET, A
通讯作者：
GASET, A
影响因子：
1.8
作者：
Dai, LX;Hou, XL;Zhou, YG
通讯作者：
Zhou, YG