Copper-Catalyzed Difunctionalization of Allenes with Sulfonyl Iodides Leading to (<i>E</i>)-α-Iodomethyl Vinylsulfones
作者:Ning Lu、Zhiguo Zhang、Nana Ma、Conghui Wu、Guisheng Zhang、Qingfeng Liu、Tongxin Liu
DOI:10.1021/acs.orglett.8b01765
日期:2018.7.20
A highly regioselective iodosulfonylation of allenes in the presence of CuI and 1,10-phenanthroline has been developed for the synthesis of various useful (E)-α-iodomethyl vinylsulfones in moderate to excellent yields. This practical reaction is fast, operationally simple, and in particular, proceeds under very mild conditions to afford the target products with high regio- and stereoselectivity. The
An efficient RhII -catalyzed synthesis of functionalized α-vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C-C bond cleavage of the cyclopropane intermediates leads to formation of α-vinyl aldehyde derivatives
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。
Asymmetric Nitrone Synthesis via Ligand-Enabled Copper-Catalyzed Cope-Type Hydroamination of Cyclopropene with Oxime
We report realization of the first enantioselective Cope-type hydroamination of oximes for asymmetric nitrone synthesis. The ligand promoted asymmetriccyclopropene “hydronitronylation” process employs a Cu-based catalytic system and readily available starting materials, operates under mild conditions and displays broad scope and exceptionally high enantio- and diastereocontrol. Preliminary mechanistic
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