A mild rhodium catalytic system has been developed to synthesize vinylcyclopropa[b]indolines through cyclopropanation of indoles with vinyl carbenoids generated from ringopening of cyclopropenes in situ. By employing a Rh-migration strategy, the products can be obtained with good to excellent E:Z ratios (≤99:1) and complete diastereoselectivity (≤99:1). This method is easy, has a low catalyst loading
已开发出一种温和的铑催化体系,通过将吲哚与原位环丙烯开环生成的乙烯基类胡萝卜素进行环丙烷化,来合成乙烯基环丙烷[ b ]二氢吲哚。通过采用Rh迁移策略,可以获得具有良好或优异的E:Z比(≤99:1)和完全非对映选择性(≤99:1)的产物。该方法容易,催化剂负载低并且适用于广泛的功能。
Rh(II)-Catalyzed [2,3]-Sigmatropic Rearrangement of Sulfur Ylides Derived from Cyclopropenes and Sulfides
作者:Hang Zhang、Bo Wang、Heng Yi、Yan Zhang、Jianbo Wang
DOI:10.1021/acs.orglett.5b01542
日期:2015.7.2
Rh2(OAc)4-catalyzed [2,3]-sigmatropicrearrangement of sulfurylides is reported. A series of cyclopropenes were successfully employed for [2,3]-sigmatropicrearrangement by a reaction with either allylic or propargylic sulfides. Under the optimized conditions, the reaction afforded the products in moderate to excellent yields. In these transformations, the vinyl metal carbenes generated in situ from the cyclopropenes
Rhodium-Catalyzed Intermolecular Cyclopropanation of Benzofurans, Indoles, and Alkenes via Cyclopropene Ring Opening
作者:Rachel J. Ross、Rubaishan Jeyaseelan、Mark Lautens
DOI:10.1021/acs.orglett.0c01655
日期:2020.6.19
The generation of metal carbenoids viaringopening of cyclopropenes by transition metals offers a simple entry into highly reactive intermediates. Herein, we describe a diastereoselective intermolecular rhodium-catalyzed cyclopropanation of heterocycles and alkenes using cyclopropenes as carbene precursors with a low loading of a commercially available rhodium catalyst. The reported method is scalable
Reactions of Vinylidenecyclopropanes with Diphenyl Diselenide in the Presence of AIBN and Thermally-Induced Further Transformations
作者:Wei Yuan、Yin Wei、Min Shi、Yuxue Li
DOI:10.1002/chem.201103461
日期:2012.1.27
vinylidenecyclopropanes with diphenyl diselenide in the presence of AIBN and upon heating gives the corresponding bicyclo[3.1.0]hexane derivatives in good yields. These compounds undergo thermal‐induced radical 1,4‐hydrogen shifts through a ring‐opening pathway of allylic cyclopropane to give the corresponding cyclohexene derivatives stereoselectively in good yields at 200 °C (see scheme).
An Efficient Method for the Synthesis of Alkylidenecyclobutanones by Gold-Catalyzed Oxidative Ring Enlargement of Vinylidenecyclopropanes
作者:Wei Yuan、Xiang Dong、Yin Wei、Min Shi
DOI:10.1002/chem.201201161
日期:2012.8.20
Rings of gold: Vinylidenecyclopropanes can undergo efficientoxidativeringenlargements under mild conditions to give the corresponding alkylidenecyclobutanone derivatives in good yields (see scheme). A plausible mechanism for this transformation has been proposed, and a new AuI–N complex, which can be used as an efficient catalyst in this oxidation reaction, has been isolated.
金戒指:亚乙烯基环丙烷在温和的条件下可以进行有效的氧化环扩环,从而以高收率得到相应的亚烷基环丁酮衍生物(参见方案)。已经提出了这种转化的合理机制,并且已经分离出可以用作该氧化反应的有效催化剂的新的Au I – N络合物。