Cationic palladium(<scp>ii</scp>)-catalyzed dehydrative nucleophilic substitutions of benzhydryl alcohols with electron-deficient benzenethiols in water
作者:Hidemasa Hikawa、Yumo Machino、Mariko Toyomoto、Shoko Kikkawa、Isao Azumaya
DOI:10.1039/c6ob01140c
日期:——
An efficient direct nucleophilic substitution of benzhydryl alcohols with electron-deficient benzenethiols using cationic Pd(II) catalysts as Lewis acids in water is reported. Atom economical and environmentally benign protocols afford S-benzylated products in moderate to excellent yields. Commercially available Pd(MeCN)4(OTf)2, PdCl2(MeCN)2, and Na2PdCl4 are highly efficient catalysts. Notably, this
报道了使用阳离子Pd(II)催化剂作为路易斯酸在水中用缺电子的苯硫醇对苯二酚进行有效的直接亲核取代。原子经济和环保的协议可提供中等至极好的收率的S-苄基化产物。市售的Pd(MeCN)4(OTf)2,PdCl 2(MeCN)2和Na 2 PdCl 4是高效催化剂。值得注意的是,无需任何其他添加剂(例如酸,碱或外部配体)就可以实现此简单方案。Hammett研究S的速率常数通过使用各种取代的苄醇进行的苄基化反应产生负ρ值,这表明在过渡态中会积聚正电荷。