Non-Innocent Behavior of Substrate Backbone Esters in Metal-Catalyzed Carbocyclizations and Friedel–Crafts Reactions of Enynes and Arenynes
作者:Bastien Michelet、Guillaume Thiery、Christophe Bour、Vincent Gandon
DOI:10.1021/acs.joc.5b02052
日期:2015.11.6
of metal-catalyzed carbocyclization reactions. The non-innocent role of the ester functionality in lowering the activation barrier of the key step of the gallium- and indium-catalyzed cycloisomerization of 1,6-enynes is revealed. In the case of the gallium-catalyzed hydroarylation of arenynes, the esters in the tether can deprotonate the Wheland intermediate, thus avoiding more energetically demanding
根据DFT计算和实验结果,我们表明有机基团主链中酯基的存在会影响金属催化的碳环化反应的机理。揭示了酯官能团在降低镓和铟催化的1,6-烯炔的环异构化关键步骤的活化势垒方面的非清白作用。在芳烃的镓催化加氢芳基化的情况下,系链中的酯可以使Wheland中间体去质子化,从而避免了更强烈地要求[1,3]-或[1,2] / [1,2] -H的转变。作为镓催化的Friedel-Crafts烷基化,不同寻常的协调一致的小号Ë已经计算出涉及酯的Ar机理。最后,计算证据表明丙酸甲酯的酯基能够在铂催化的分子内氢芳基化反应中形成发散机理。