在几种瑞香生物碱中发现的[5-6-7]氮杂三环ABC核心是通过一种新途径合成的,其中包括全氢吲哚酮的扩环以提供AC环系统和自由基B环闭合作为关键步骤。已报道的八氢-1,7-乙醇环庚[ b ]吡咯的官能化水平表明它们可以作为该生物碱领域的有价值的构建模块。还报道了通过 2-氮杂双环[3.3.1]壬烷扩环首次合成同吗啡烷。
A cyanoborohydride‐promoted radicalcyclization methodology has been developed to access α‐chlorolactams in a simple and efficient way using NaBH3CN and trichloroacetamides easily available from allylic and homoallylic secondary amines. This methodology allowed the synthesis of a library of α‐chlorolactams (mono‐ and bicyclic), which were tested for herbicidal activity, trans‐3‐chloro‐4‐methyl‐1‐(
Radical promoted cyclisations of trichloroacetamides with silyl enol ethers and enol acetates: the role of the hydride reagent [tris(trimethylsilyl)silane vs. tributylstannane]
Reactions between 1-(carbamoyl)dichloromethyl radicals and electron-rich alkenes acting as radical acceptors are reported for the first time. The intramolecular reaction of trichloroacetamides with silyl enol ethers gives ketones using (TMS)3SiH as the mediator, and alcohols when using Bu3SnH. The reaction with enol acetates gives acetates using either of the above hydride reagents. These radical processes have been applied to the synthesis of 2-azabicyclo[3.3.1]nonanes.
Cu(i)-catalyzed atom transfer radical cyclization of trichloroacetamides tethered to electron-deficient, -neutral, and -rich alkenes: synthesis of polyfunctionalized 2-azabicyclo[3.3.1]nonanes
作者:Faïza Diaba、Agustín Martínez-Laporta、Josep Bonjoch、Ana Pereira、José María Muñoz-Molina、Pedro J. Pérez、Tomás R. Belderrain
DOI:10.1039/c2cc34133f
日期:——
A novel synthetic entry to 2-azabicyclo[3.3.1]nonanes based on a copper(I)-catalyzed intramolecular coupling of amino-tethered trichloroacetamides and unsaturated nitriles, esters and alkenes, as well as enolacetates, is described. A study of the reaction conditions and the scope of the process is reported.
Atom Transfer Radical Cyclization of Trichloroacetamides to Electron-Rich Acceptors Using Grubbs’ Catalysts: Synthesis of the Tricyclic Framework of FR901483
Intramolecular Kharasch-type additions of trichloroacetamides on anisole and enol acetates catalyzed by Grubbs' ruthenium carbenes are described. This protocol provides access to highly functionalized 2-azaspiro[4.5]decanes, morphan compounds, and the azatricyclic core of FR901483.