Selective Synthetic Routes to Sterically Hindered Unsymmetrical Diaryl Ketones via Arylstannanes
作者:Marcos J. Lo Fiego、Gustavo F. Silbestri、Alicia B. Chopa、María T. Lockhart
DOI:10.1021/jo102366q
日期:2011.3.18
bulky aroyl chlorides are good reaction partners for the synthesis of two-, three-, and even four-ortho-substituted benzophenones, in good to excellent isolated yields (47−91%). Three simple and direct routes, with differential advantages, are proposed: (i) a catalyst-free protocol, in o-dichlorobenzene (ODCB) at 180 °C; (ii) a room temperature protocol, using AlCl3 (0.5 equiv), in dichloromethane (DCM);
庞大的芳基锡烷和大体积的芳酰氯是合成二,三,甚至四取代的二苯甲酮的良好反应伙伴,分离产率好至极好(47-91%)。提出了三种具有不同优势的简单直接途径:(i )在180°C的邻二氯苯(ODCB)中无催化剂的方案;(ii)在二氯甲烷(DCM)中使用AlCl 3(0.5当量)的室温实验方案;(iii)无溶剂,铟促进的方法。对于铟介导的反应,提出了一种自由基机理。