Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala Biomedical Center, Uppsala University , P.O. Box 574, SE-751 23 Uppsala, Sweden.
J Org Chem. 2017 Mar 3;82(5):2515-2522. doi: 10.1021/acs.joc.6b02894. Epub 2017 Feb 15.
A Pd-catalyzed and ligand-free carbonylation/cycloaddition/decarboxylation cascade synthesis of sulfonyl amidines from sulfonyl azides and substituted amides at low CO pressure is reported. The reaction proceeds via an initial Pd-catalyzed carbonylative generation of sulfonyl isocyanates from sulfonyl azides, followed by a [2 + 2] cycloaddition with amides and subsequent decarboxylation, which liberates the desired sulfonyl amidines, generating N and CO as the only reaction byproducts. Using this simple protocol, a diverse range of sulfonyl amidines was obtained in moderate to excellent yields. In addition, the reaction can also be directed through a more conventional amidocarbonylation pathway by employing N-monosubstituted amide nucleophiles to afford acyl sulfonyl ureas in good yields.
报道了一种在低 CO 压力下，通过 Pd 催化和无配体的羰基化/环加成/脱羧反应级联合成磺酰基脒的方法，该方法使用磺酰基叠氮化物和取代酰胺。反应通过 Pd 催化的羰基化反应从磺酰基叠氮化物生成磺酰基异氰酸酯开始，然后与酰胺进行 [2 + 2] 环加成，接着进行脱羧反应，释放出所需的磺酰基脒，生成 N 和 CO 作为唯一的反应副产物。使用这种简单的方案，可以中等至优异的收率得到各种磺酰基脒。此外，通过使用 N-单取代酰胺亲核试剂，该反应还可以通过更传统的氨甲酰化途径进行导向，以良好的收率得到酰基磺酰基脲。
