N 2-取代的三唑和三嗪衍生物的直接合成一直是N-杂环化学中的挑战。在铜(II)催化下,烯酮N,S-乙缩醛(即烷硫基取代的烯胺酮)与芳基重氮盐有效反应,从而可以选择性选择性地生成功能多样的N2-取代的1,2,3-三唑和2,3-二氢键-1,2,4-三嗪。氧化剂和碱依赖性反应分别产生五元和六元的N-杂环产物。合成方案具有宽泛的底物范围,在温和条件下具有良好的官能团耐受性。机理研究表明,反应是通过烯基偶氮/亚氨基中间体进行的。
Mediated by a catalytic amount of FeCl3, the C–H alkylation of S,S‐functionalized internal olefins, i.e., α‐oxo ketene dithioacetals and their analogues, was efficiently achieved using simple ethers and toluene derivatives as the coupling partners, di‐tert‐butyl peroxide (DTBP) as the oxidant, and DABCO⋅6 H2O as the additive. The alkylthio functionality is essential for the internal olefinic C–H bond
S-functionalized internal olefins, that is, α-oxo ketene dithioacetals, was efficiently achieved with alcohols as the alkoxylating agents, (diacetoxyiodo)benzene (PhI(OAc)2) as the oxidant, and benzoquinone (BQ) as the co-oxidant. The alkoxylated olefins were thus constructed and applied for the synthesis of alkoxylated N-heterocycles. Polarization of the olefinic carbon-carbon doublebond by the electron-donating
Three-Component Synthesis of Indanone-Fused Spirooxindole Derivatives
作者:Xue-Bing Chen、Xi-Ming Liu、Rong Huang、Sheng-Jiao Yan、Jun Lin
DOI:10.1002/ejoc.201300376
日期:2013.7
A simple, straightforward and versatile multicomponent protocol for the synthesis of indanone-fused spirooxindole derivatives has been developed. The strategy involves the one-pot three-component reaction of heterocyclic ketene aminals, 1H-indene-1,3(2H)-dione and the dicarbonyl compounds isatins or acenaphthenequinone in an ethanol/water medium catalysed by p-TSA at reflux. Mild reaction conditions
Photoredox-Catalyzed C–H Arylation of Internal Alkenes to Tetrasubstituted Alkenes: Synthesis of Tamoxifen
作者:Quannan Wang、Xiaoge Yang、Ping Wu、Zhengkun Yu
DOI:10.1021/acs.orglett.7b03223
日期:2017.11.17
Visible-light-induced direct C–H arylation of S,S-functionalized internal alkenes, that is, α-oxo ketene dithioacetals and analogues, has been efficiently realized with aryldiazonium salts (ArN2BF4) as coupling partners and Ru(bpy)3Cl2·6H2O as photosensitizer at ambient temperature. The strategy to activate the internal olefinic C–H bond by both the alkylthio and electron-withdrawing functional groups
Copper(II)-Mediated Intramolecular Cyclopropanation of Ketene <i>N</i>,<i>X</i>-Acetals (X = S, O, N) under Mild Conditions
作者:Fei Huang、Ping Wu、Zhengkun Yu
DOI:10.1021/acs.joc.0c00093
日期:2020.3.20
CuBr2-mediated intramolecular oxidative cyclopropanation of α-oxo ketene N,S-acetals was efficiently achieved to afford 2-thioalkyl-3-azabicyclo-[3.1.0]hexenes under mild conditions. 2-Oxyalkyl- and 2-aminoallyl-3-azabicyclo-[3.1.0]hexenes were also obtained from the corresponding α-oxo ketene N,O- and N,N-acetals. Further C-S bond transformations led to diverse 2-aryl-substituted 3-azabicyclo[3.1