β-amino esters from the reductive ring opening of aziridine-2-carboxylates.
β-amino esters from the reductive ring opening of aziridine-2-carboxylates.
复制标题
DOI：
10.1021/jo501694h
复制
发表时间：
2014-11-07
期刊：
影响因子：
--
通讯作者：
Wulff WD
中科院分区：
文献类型：
--
作者：
Zhao W;Lu Z;Wulff WD
研究了氮丙啶-2-羧酸酯与二碘化钐还原开环反应的反应范围。C-C和C-N键断裂之间的竞争作为氮丙啶的N-取代基的性质，氮丙啶的3-位中的取代基的性质的函数进行检查，以及在3-位中的取代基是否与在2-位中的羧酸酯处于顺式或反式关系。所需的C-N键断裂导致β-氨基酯，其是大多数具有N-活化基团的氮丙啶的主要产物。然而，观察到C-C裂解产物在3-位具有芳基;这对于顺式氮杂环丙烷尤其明显，其中观察到两者的几乎相等的混合物。观察到所有氮杂环丙烷与强N-活化对甲苯磺酸酯基团的C-N裂解产物的排他性形成。类似地，对于2-三甲基甲硅烷基乙基磺酸酯基团（SES）观察到高选择性，其更容易除去。这些方法的实用性在从相同氮丙啶合成（R）-β3-DOPA和l-DOPA的保护形式中得到说明，前者通过SmI 2介导的C-2还原性打开，后者通过钯介导的C-3还原性打开。
A general study is undertaken to examine the scope of the reductive ring opening of aziridine-2-carboxylates with samarium diiodide. The competition between C–C and C–N bond cleavage is examined as a function of the nature of the N-substituent of the aziridine, the nature of the substituent in the 3-position of the aziridine, and whether the substituent in the 3-position is in a cis or trans relationship with the carboxylate in the 2-position. The desired C–N bond cleavage leads to β-amino esters that are the predominant products for most aziridines with an N-activating group. However, C–C cleavage products are observed with an aryl group in the 3-position; this can be particularly pronounced with cis-aziridines where a nearly equal mixture of the two is observed. Exclusive formation of the C–N cleavage product is observed for all aziridines with the strongly N-activating p-toluene sulfonate group. Similarly high selectivity is observed for the 2-trimethylsilylethyl sulfonate group (SES), which is easier to remove. The utility of these methods is illustrated in the synthesis of protected forms of (R)-β3-DOPA and l-DOPA from the same aziridine, the former by SmI2-mediated reductive opening at C-2 and the latter by palladium-mediated reductive opening at C-3.
登录
查看更多内容
影响因子：
15
作者：
Hu, Gang;Gupta, Anil K.;Wulff, William D.
通讯作者：
Wulff, William D.
DOI：
10.1039/b102578n
发表时间：
2001-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1
影响因子：
--
作者：
Aggarwal, VK;Ferrara, M;Fieldhouse, R
通讯作者：
Fieldhouse, R
影响因子：
15
作者：
Desai, Aman A.;Wulff, William D.
通讯作者：
Wulff, William D.
影响因子：
4.3
作者：
Guan, Yong;Ding, Zhensheng;Wulff, William D.
通讯作者：
Wulff, William D.
影响因子：
7.3
作者：
Huynh, Tri H. V.;Shim, Irene;Bunch, Lennart
通讯作者：
Bunch, Lennart