The direct nucleophilic addition to amides represents an attractive methodology in organic synthesis that tackles amidic resonance by ground-state destabilization. This approach has been recently accomplished with carbon, nitrogen and oxygen nucleophiles. Herein, we report an exceedingly mild method for the direct thioesterification and selenoesterification of amides by selective N–C(O) bond cleavage in the absence of transition metals. Acyclic amides undergo N–C(O) to S/Se–C(O) interconversion to give the corresponding thioesters and selenoesters in excellent yields at room temperature via a tetrahedral intermediate pathway (cf. an acyl metal).
对酰胺的直接亲核加成代表了有机合成中一种吸引人的方法论,通过基态不稳定化来解决酰胺的共振问题。最近,已经成功地利用碳、氮和氧亲核试剂实现了这种方法。在这里,我们报告了一种极其温和的方法,通过选择性N-C(O)键裂解,在没有过渡金属的情况下直接对酰胺进行硫酯化和硒酯化。无环酰胺经历N-C(O)到S/Se-C(O)的相互转化,在室温下通过四面体中间体途径(与酰基金属相比)以极高的产率给出相应的硫酯和硒酯。