Unsymmetrical Diarylmethanes by Ferroceniumboronic Acid Catalyzed Direct Friedel–Crafts Reactions with Deactivated Benzylic Alcohols: Enhanced Reactivity due to Ion-Pairing Effects
作者:Xiaobin Mo、Joshua Yakiwchuk、Julien Dansereau、J. Adam McCubbin、Dennis G. Hall
DOI:10.1021/jacs.5b05076
日期:2015.8.5
displays a broader scope compared to previously reported catalysts for similar Friedel-Crafts reactions of benzylicalcohols, including other boronic acids such as 2,3,4,5-tetrafluorophenylboronic acid. The efficacy of the new boronic acid catalyst was confirmed by its ability to activate primary benzylicalcohols functionalized with destabilizing electron-withdrawing groups like halides, carboxyesters
Diarylmethane synthesis through Re<sub>2</sub>O<sub>7</sub>-catalyzed bimolecular dehydrative Friedel–Crafts reactions
作者:Qi Qin、Youwei Xie、Paul E. Floreancig
DOI:10.1039/c8sc03570a
日期:——
describes the application of Re2O7 to the syntheses of diarylmethanes from benzylic alcohols through solvolysis followed by Friedel–Craftsalkylation. The reactions are characterized by broad substrate scope, low catalyst loadings, high chemical yields, and minimal waste generation. The intermediate perrhenate esters are superior leaving groups to chlorides and bromides in these reactions. The polarity
该手稿描述了 Re 2 O 7在通过溶剂分解和弗里德尔-克来福特烷基化从苯甲醇合成二芳基甲烷中的应用。该反应的特点是底物范围广、催化剂负载量低、化学产率高和废物产生最少。在这些反应中,中间体高铼酸酯是优于氯化物和溴化物的离去基团。六氟异丙醇的极性和水封存能力对于这些过程的成功至关重要。Re 2 O 7是 HOReO 3的预催化剂,可作为这些反应的成本较低且易于处理的促进剂。氧铼催化剂在类似取代的乙酸酯存在下选择性地活化醇,这表明与布朗斯台德酸催化相比具有独特的化学选择性和机制。