这项工作报告了第一个可见光介导的钴催化醛与简单烯烃的烯丙基化反应以生产均烯丙醇。这种新颖的策略直接使用容易获得的未活化烯烃作为替代烯丙基来源,而不是预先合成的烯丙基卤化物/醇,从而绕过了对外源还原剂的需求。机理研究表明,在光氧化还原条件下,烯丙基自由基中间体和 Co I物种的前所未有的组合产生亲核 π-烯丙基钴II代表了催化循环中的关键步骤。
An efficient synthesis of carbazoles from PtCl2-catalyzed cyclization of 1-(indol-2-yl)-2,3-allenols
作者:Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1039/b909649c
日期:——
The PtCl2-catalyzed reaction of 1-(indol-2-yl)-2,3-allenols occurred smoothly to form carbazoles by connecting the 3-carbon atom of indole with the 4-carbon atom of the allenol moiety, referring to the carbon atom connected to the hydroxyl group.
Efficient synthesis of carbazoles via PtCl2-catalyzed RT cyclization of 1-(indol-2-yl)-2,3-allenols: scope and mechanism
作者:Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1039/c1ob06474f
日期:——
A detailed study on the scope of the efficient PtCl2-catalyzed synthesis of carbazoles from 1-(indol-2-yl)-2,3-allenols is described. Through isotopic labeling experiments, it is confirmed that the reaction proceeds through a unique metal carbene intermediate, which undergoes subsequent highly selective 1,2-hydrogen migration to afford carbazoles. The reaction shows wide scope and allows the introduction of a variety of different substituents at different positions on the carbazole due to the substituent-loading capability of both indole and the allene moiety.
allylation with simple alkenes to produce homo-allylic alcohols. This novel strategy directly uses easily available unactivated alkenes as alternative allyl sources instead of pre-synthesized allylic halides/alcohols, thus bypassing the need for exogeneous reductants. Mechanistic studies suggest that the unprecedented combination of allyl radical intermediates and CoI species to generate nucleophilic π-allylcobaltII
这项工作报告了第一个可见光介导的钴催化醛与简单烯烃的烯丙基化反应以生产均烯丙醇。这种新颖的策略直接使用容易获得的未活化烯烃作为替代烯丙基来源,而不是预先合成的烯丙基卤化物/醇,从而绕过了对外源还原剂的需求。机理研究表明,在光氧化还原条件下,烯丙基自由基中间体和 Co I物种的前所未有的组合产生亲核 π-烯丙基钴II代表了催化循环中的关键步骤。