Palladium-Catalyzed C−H Functionalization of Pyridine <i>N</i>-Oxides: Highly Selective Alkenylation and Direct Arylation with Unactivated Arenes
作者:Seung Hwan Cho、Seung Jun Hwang、Sukbok Chang
DOI:10.1021/ja8026295
日期:2008.7.1
Two catalytic protocols of the oxidative C-C bond formation have been developed on the basis of the C-H bond activation of pyridine N-oxides. Pd-catalyzed alkenylation of the N-oxides proceeds with excellent regio-, stereo-, and chemoselectivity, and the corresponding ortho-alkenylated N-oxide derivatives are obtained in good to excellent yields. Direct cross-coupling reaction of pyridine N-oxides
在吡啶 N-氧化物的 CH 键活化的基础上开发了两种氧化 CC 键形成的催化方案。Pd 催化的 N-氧化物的烯基化以优异的区域选择性、立体选择性和化学选择性进行,并且相应的邻位烯基化 N-氧化物衍生物以良好到优异的产率获得。在 Pd 催化剂和 Ag 氧化剂的存在下,还开发了吡啶 N-氧化物与未活化芳烃的直接交叉偶联反应,这提供了具有高位点选择性的邻芳基化吡啶 N-氧化物产物。