Radical Changes in Lewis Acid Catalysis: Matching Metal and Substrate
作者:Tim Bleith、Qing-Hai Deng、Hubert Wadepohl、Lutz H. Gade
DOI:10.1002/anie.201603072
日期:2016.6.27
stereochemical rigidity of the coordination sphere of boxmi/CuII catalysts is key to achieving high enantioselectivity in the electrophilic alkylation of β‐ketoesters, this pathway is outperformed by a radical process for the corresponding catalytic transformation of oxindoles, giving rise to racemic products. For the corresponding ZnII catalysts, the selectivity in the latter process is outstanding despite
尽管boxmi / Cu II催化剂的配位域的立体化学刚度是在β-酮酸酯的亲电烷基化中实现高对映选择性的关键,但该途径却被相应的羟吲哚催化转化的自由基过程所超越,产生了外消旋产物。对于相应的Zn II催化剂,尽管配位壳具有更大的可塑性,但后者的选择性却非常出色。因此,该反应发展成为一种高度有用的合成方法,该方法能够以高收率和对映选择性转化多种底物。
Oxindole derivatives
申请人:Luk Kim-Chun
公开号:US20060293319A1
公开(公告)日:2006-12-28
The invention describes compounds of the general formula I
or the pharmaceutically acceptable salts thereof,
wherein R
1
, R
2
, R
3
and X are herein described,
a process for their manufacture, medicaments containing them as well as the use of these compounds as pharmaceutically active agents. The compounds show activity as antiproliferative agents and may be especially useful for the treatment of cancer.
Catalytic asymmetric α‐arylation of N‐unprotected 3‐substituted oxindoles with diaryliodoniumsalts has been realized by a chiral Lewis acid promoted electrophilic addition and aryl‐rearrangement process. Single C3‐arylated products containing a quaternary carbon center were generated in high enantioselectivity and reactivity.
The field of asymmetric catalysis has been developed by exploring noncovalent interactions, particularly within N-heterocyclic carbene-mediated processes. Despite challenges due to the limited number of compatible electrophiles (predominantly π-acceptors), this study introduces the first asymmetric α-alkylation of 3-aryl oxindoles using Csp3 electrophiles. The innovative protocol integrates diverse
不对称催化领域是通过探索非共价相互作用而发展起来的,特别是在 N-杂环卡宾介导的过程中。尽管由于相容亲电子试剂(主要是 π 受体)数量有限而面临挑战,本研究首次使用 C sp3亲电子试剂对 3-芳基羟吲哚进行不对称 α-烷基化。该创新方案集成了多种羟吲哚和烷基、烯丙基和炔丙基亲电子试剂,实现了高产率和对映选择性。初步的机理探索支持非共价催化机制,增强了构建具有潜在应用的复杂手性分子的工具包。