Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
Nature. 2023 Aug;620(7976):1007-1012. doi: 10.1038/s41586-023-06347-3. Epub 2023 Jun 26.
Chemical transformations that introduce, remove or manipulate functional groups are ubiquitous in synthetic chemistry. Unlike conventional functional-group interconversion reactions that swap one functionality for another, transformations that alter solely the location of functional groups are far less explored. Here, by photocatalytic, reversible C-H sampling, we report a functional-group translocation reaction of cyano (CN) groups in common nitriles, allowing for the direct positional exchange between a CN group and an unactivated C-H bond. The reaction shows high fidelity for 1,4-CN translocation, frequently contrary to inherent site selectivity in conventional C-H functionalizations. We also report the direct transannular CN translocation of cyclic systems, providing access to valuable structures that are non-trivial to obtain by other methods. Making use of the synthetic versatility of CN and a key CN translocation step, we showcase concise syntheses of building blocks of bioactive molecules. Furthermore, the combination of C-H cyanation and CN translocation allows access to unconventional C-H derivatives. Overall, the reported reaction represents a way to achieve site-selective C-H transformation reactions without requiring a site-selective C-H cleavage step.
在合成化学中，引入、去除或操作官能团的化学转化无处不在。与传统的官能团相互转化反应不同，仅改变官能团位置的转化反应探索得较少。在这里，通过光催化、可逆 C-H 采样，我们报告了常见腈中的氰基 (CN) 基团的官能团迁移反应，允许 CN 基团和未活化的 C-H 键之间直接进行位置交换。该反应对 1,4-CN 迁移具有高保真度，通常与传统 C-H 官能化中的固有位点选择性相反。我们还报告了环状系统的直接环间 CN 迁移，为通过其他方法难以获得的有价值结构提供了途径。利用 CN 的合成多功能性和关键的 CN 迁移步骤，我们展示了生物活性分子构建块的简洁合成。此外，C-H 氰化和 CN 迁移的组合可获得非常规的 C-H 衍生物。总的来说，所报道的反应代表了一种在不需要选择性 C-H 断裂步骤的情况下实现选择性 C-H 转化反应的方法。
