The Strecker reaction in supercritical CO2 was carried out for the first time at the Zelinsky Institute
α-Aminonitriles are valuable intermediates in organic synthesis on the way to α-amino acids and 1,2-diamines, and are also of interest due to their biological activity. Many anticancer and antidiabetic drugs contain an α-aminonitrile fragment in their structure. The three-component condensation of carbonyl compounds with amines and a cyanating agent, discovered by Strecker in 1850, is one of the most convenient methods for the synthesis of α-aminonitriles. The most commonly used cyanating agents are hydrocyanic acid, its organic derivatives (trimethylsilyl cyanide, acetonecyanohydrin) or salts with alkali metals. The latter are the most accessible and safe to handle due to the absence of toxic and flammable vapors.
Researchers of the Nazarov Laboratory of Fine Organic Synthesis of the Zelinsky Institute for the first time carried out the Strecker reaction with the participation of KCN in supercritical carbon dioxide, which plays the role of both an eco-friendly reaction medium and a promoter of the chemical process itself. The water formed in situ during the condensation of the amine with the aldehyde is converted under the proposed conditions into carbonic acid, which provides a gradual release of the true cyanating agent (HCN) from KCN. The reaction takes place in a sealed autoclave, which guarantees complete absorption of HCN in the reaction and excludes the chemist's exposure to its toxic vapors. The process conditions easily achievable in industry (90 bar, 35 ° C), as well as the scalability of the synthesis, make it possible to consider it as a possible basis for the development of environmentally friendly industrial technologies for the production of biologically active substances.
Ruslan V. Fauziev, Roman E. Ivanov, Ilya V. Kuchurov, Sergei G. Zlotin A carbon dioxide-promoted three-component Strecker reaction Green Chem., 2021,23, 10137-10144. DOI: 10.1039/d1gc03161a.