N-Cyano amides are pivotal in agrochemicals, biologically active compounds, and nitrogen-containing heterocycles synthesis. Here, we present an umpolung cyanation strategy for the synthesis of N-cyano amides. By applying the readily accessible O-tosyl hydroxamates as nitrogen electrophiles, direct nucleophilic cyanation can be achieved with trimethylsilyl cyanide (TMSCN) under mild and transition metal-free conditions. This protocol features excellent functional group tolerance, easy scalability, and broad substrate scope (over 70 examples). Moreover, preliminary experimental studies and density functional theory (DFT) calculations support an SN2-type mechanism of this reaction. Our work not only provides efficient, robust, and practical approaches to a variety of useful and complex N-cyano amide molecules but also expands the concept and scope of SN2-type reaction at the non-anomeric amide electrophilic nitrogen center.
Yang et al. (Tue,) studied this question.