Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• heterocyclic azides followed by a Cornforth-type rearrangement to the final products. The reaction is tolerant to various N-monosubstituted 3,3-diaminoacrylonitriles and to different heterocyclic azides. The developed method has a broad scope and can be applied to obtain a variety of N-heteroaryl-1,2,3

• -triazole-4-carbimidamides with alkyl, allyl, propargyl, benzyl, cycloalkyl, and indolyl substituents at the N1 position . Keywords: Cornforth rearrangement; cycloaddition reactions; 3,3-diaminoacrylonitriles; heterocyclic azides; 1,2,3-triazole; Introduction Heteroaryl amidines are widely used in the

• the structure of the prepared compounds. To explain the outcome of the tandem reaction of 3,3-diaminoacrylonitriles to heterocyclic azides, a tentative mechanism for the formation of 1,2,3-triazoles 3 from acrylonitriles 1 and azides 2 is shown in Scheme 3. Firstly, treatment with a base, leads to