Heterocyclization of amides of alkenylcarboxylic acids

Abstract

The latest published data on heterocyclization of amides of alkenylcarboxylic acids have been systematized. It has been proven that the electrophilic intramolecular cyclization reaction of functionally substituted olefins opened in the 70s of the last century is a convenient way of constructing different oxygen-, nitrogen- and sulfurcontaining heterocyclic compounds. It has been noted that anilides of unsaturated carboxylic acids as bifunctional nucleophilic systems containing alkenyl and aminocarbonyl functions are useful models to study the electrophilic cyclization reaction, which leads to formation of O- and N-containing heterocycles (lactones and lactams). The last of them belong to the important types of compounds used as key blocks in the synthesis of biologically ctive alkaloids and their analogues, pharmaceutical and agrochemical products. The effective approaches to the synthesis of new types of functionalized lactones and lactams have been developed; amides of 3-butenoic, 4-pentenoic and 5-hexenoic acids are often used as substrates for their design. Along with classical methods of synthesis of lactones and lactams the literary sources relating to the use of original catalytic electrophilic systems (Nolan, Grubbs, Hoveyda), the metathesis reaction and radical processes in regio- and stereoselective cyclization of amides under mild conditions have been analyzed and summarized in the article. The synthetic versions considered are general in nature and allow to perform the targeted functionalization of O-, N-, S-containing heterocyclic small and medium-sized systems along with the cyclization processes.