Dichloro‐Substituted 1,2‐Diazabuta‐1,3‐dienes as Highly Reactive Electrophiles in the Reaction with Amines and Diamines: Efficient Synthesis of α‐Hydrazo Amidinium Salts

• Published in: European journal of organic chemistry 2018-09, Vol.2018 (36), p.4996-5006
• Main Authors: Shastin, Alexey V., Sergeev, Pavel G., Lukianova, Anna I., Muzalevskiy, Vasiliy M., Khrustalev, Victor N., Dorovatovskii, Pavel V., Nenajdenko, Valentine G.
• Format: Article
• Language: English
• Subjects: Amidines; Amines; Chemical synthesis; Diamines; Dienes; Heterodienes; Hydrazones; Nitrogen heterocycles; Synthetic methods
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201800441

The reaction of 4,4‐dichloro‐1,2‐diazabuta‐1,3‐dienes with various amines and diamines was studied. We found that in this reaction, the starting diazabutadienes behave as highly reactive electrophiles to open up a straightforward route to the corresponding amidinium salts with a hydrazone functionality in the adjacent position. The reaction was found to be very general; as a rule, all the products could be prepared in almost quantitative yields. We also demonstrated that the prepared amidinium salts could be used as versatile building blocks for the synthesis of polyfunctional molecules. The reaction of primary and secondary amines with dichloro‐substituted 1,2‐diazabuta‐1,3‐dienes gave the corresponding amidinium salts with a hydrazo group at the α position. These polyfunctional products were prepared in up to quantitative yield. The reaction with diamines opens access to five‐ and six‐membered‐ring derivatives which can be used as ligands for coordination chemistry.