Synthesis of substituted pyridines and pyridazines via ring closing metathesis
作者:Timothy J. Donohoe、Lisa P. Fishlock、José A. Basutto、John F. Bower、Panayiotis A. Procopiou、Amber L. Thompson
DOI:10.1039/b904363b
日期:——
RCM can be used to make aromatic heterocycles, namely pyridines and, for the first time, pyridazines; the key step after RCM involves elimination of sulfinate to provide the aromatic system.
Intramolecular Simmons−Smith Cyclopropanation. Studies into the Reactivity of Alkyl-Substituted Zinc Carbenoids, Effect of Directing Groups and Synthesis of Bicyclo[<i>n</i>.1.0]alkanes
作者:James A. Bull、André B. Charette
DOI:10.1021/ja907504w
日期:2010.2.17
explored. Substitution on the alkene and at the allylic position was well tolerated, providing the bicyclic products in high yields. Additionally, the IMSS reaction allowed a highly diastereoselective synthesis of a 5-3-5 fused tricycloalkane. These studies will have implications for the use of substituted carbenoids in cyclopropanation reactions and for directed cyclopropanation reactions as well as in
已经开发了分子内 Simmons-Smith (IMSS) 环丙烷化,为构建取代的双环烷烃提供了一种新方法。首先,以高收率制备了含有烯丙醇的功能化的偕二碘烷烃。然后研究了分子内环化形成不同环大小的过程,并证明可以成功合成双环[3.1.0]己烷和双环[4.1.0]庚烷。更大的链长导致含末端烯烃的产物。Analysis of the product distribution for the different ring sizes and under various reaction conditions provided insight into the reactivity of substituted zinc carbenoids, and by the appropriate choice of conditions cyclopropanation could be promoted
Construction of Enantioenriched Cyclic Compounds by Asymmetric Allylic Alkylation and Ring-Closing Metathesis
作者:Francesca Giacomina、Alexandre Alexakis
DOI:10.1002/ejoc.201300971
日期:2013.10
A new approach to highly enantioenrichedcycliccompounds (up to 98 % ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetricallylicalkylation and ring-closingmetathesis sequence. The starting compounds are synthetic equivalents of cyclicallylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands.
通过在一锅不对称烯丙基烷基化和闭环复分解序列中使用 ω-烯属烯丙基底物,开发了一种高度对映体富集的环状化合物(高达 98% ee)的新方法。起始化合物是环状烯丙基底物的合成等价物。该方法以 Cu 和 Ir 催化剂以及手性亚磷酰胺配体为例。
Synthesis of bicyclic ethers by a palladium-catalyzed oxidative cyclization-redox relay-π-allyl-Pd cyclization cascade reaction
作者:Michaelyn C. Lux、Melissa L. Boby、Joshua L. Brooks、Derek S. Tan
DOI:10.1039/c9cc03775f
日期:——
are of interest in probe and drug discovery. A palladium-catalyzedcascade reaction has been developed to provide efficient access to these scaffolds from readily available linear diene–diol substrates. A Pd redox-relay process is used strategically to transmit reactivity between an initial oxypalladative cyclization and a subsequent π-allyl-Pd cyclization at remote sites. The reaction affords a variety
Synthetic studies directed toward the proposed structure for heteroscyphic acid A
作者:Subhabrata Chaudhury、Shukun Li、William A. Donaldson
DOI:10.1039/b602700h
日期:——
A route to the carbon skeleton of the proposedstructure for heteroscyphic acid A was developed utilizing a Mn(III)/Cu(II) mediated oxidative free-radical cyclization and nucleophilic addition to (3-methylpentadienyl)iron(1+) cation.