Hypervalent Activation as a Key Step for Dehydrogenative <i>ortho</i>
CC Coupling of Iodoarenes
作者:Yichen Wu、Ismael Arenas、Lewis Marc Broomfield、Eddy Martin、Alexandr Shafir
DOI:10.1002/chem.201503987
日期:2015.12.14
earlier results, a direct metal‐free α‐ arylation of substituted cyclic 1,3‐diones using ArI(O2CCF3)2 reagents has been developed; unlike other arylative approaches, the arylated products retain the iodine substituent ortho to the newly formed CC bond. The mechanism is explored by using DFT calculations, which show a vanishingly small activation barrier for the CC bond‐forming step. In fact, taking
在早期结果的基础上,开发了使用ArI(O 2 CCF 3)2试剂的取代环1,3-二酮的直接无金属α-芳基化反应。与其他芳基化方法不同,芳基化产物保留了新形成的CC键邻位的碘取代基。通过使用DFT计算探索了该机理,该计算显示了CC键形成步骤的激活势垒逐渐消失。事实上,考虑在原位活化高价的高效的优势,iodoarenes示经过交叉脱氢Ç 在C C耦合 ħ邻去碘。当将Oxone用作末端氧化剂时,发现该过程受益于高价ArI(OR)2物种的快速初始形成以及硫酸酯加速的与酮的最终偶联。该方法补充了羰基化合物在金属催化的α-芳基化反应中获得的ipso选择性。