Tandem bond forming reactions based on oxidative umpolung of organomeallic reagents

将阴离子氧化为自由基或阳离子是改变阴离子中间体反应活性的重要方法，并且在与阴离子级联反应结合使用时具有潜在的用途。烯基溴化镁与对甲苯磺酰异氰酸酯加成反应和与二醋酸碘苯连续氧化环化反应在一锅内得到溴化内酰胺。这种氧化卤化反应也适用于用醛、亚胺、二氧化碳和偶氮二羧酸盐一锅合成环醚、环胺、内酯、吡唑烷。

Oxidation of an anionic species to a radical or cationic species is an important umpolung methodology for changing the reactivity of anionic intermediates, and it is potentially useful in combination with anionic cascade reactions. An addition reaction of alkenylmagnesium bromide with p-toluenesulfonyl isocyanate and consecutive oxidative cyclization with iodobenzene diacetate afforded brominated lactams in one pot. This oxidative halocyclization was also applicable to a one-pot synthesis of cyclic ether, cyclic amine, lactone, pyrazolidine using a aldehyde, imine, carbon dioxide, and azodicarboxylate, respectively.