Nucleophilic Fluoroalkylation of α,β-Enones, Arynes, and Activated Alkynes with Fluorinated Sulfones: Probing the Hard/Soft Nature of Fluorinated Carbanions
作者:Chuanfa Ni、Laijun Zhang、Jinbo Hu
DOI:10.1021/jo702479z
日期:2008.8.1
We have successfully accomplished the nucleophilic fluoroalkylation of α,β-enones, arynes, and activated alkynes with fluorinated sulfones. It was found that for acylic α,β-enones, although the reaction medium and the structure of the enones can all influence the regioselectivity of the nucleophilic alkylation reactions, the hard/soft nature of the carbanions played a major role. By using the 1,4-
我们已经成功地完成了α,β-烯酮,芳烃和活化炔烃与氟化砜的亲核氟烷基化反应。发现对于酰基α,β-烯酮,尽管反应介质和烯酮的结构都可以影响亲核烷基化反应的区域选择性,但是碳负离子的硬/软性质起主要作用。通过使用1,4-和1,2-加成产物的比率作为探针来确定上述四种卤代碳负离子的硬/软性质,这些碳负离子的柔软度顺序可以如下:[[ PhSO 2)2 CF − ](20)≈PhSO 2 CCl 2 −(32)> PhSO2 CHF - (31)> PhSO 2 CF 2 - (30)。在芳炔的氟烷基(的情况下35作为前体)和α,β-炔酮46与氟-双(苯磺酰基)甲烷(21),氟-双(苯磺酰)甲基化芳烃36和β氟-双(苯磺酰)甲基化的α,β-以高收率获得烯酮47作为相应产物。在2-氟-2-(苯磺酰基)苯乙酮(34)与芳烃或活化炔烃之间的反应期间46,分子内串联反应过程导致形成酰基-氟代烷基化的芳烃43