Shehedyn M. Synthesis of substituted thiophenes based on products of functionalized alkenes bromoarylation and their modification

The research problem of this study is the development of new approaches to the synthesis of substituted 3-amino- and 3-hydroxythiophenes and the determination of their properties. Systematic analysis of literature sources and available electronic databases allowed identifying objects and areas of research. Nowadays, the chemistry of heterocyclic compounds is undoubtedly the main branch of both organic and medical chemistry, and thiophene derivatives form an important class of heterocyclic compounds. The current state of thiophene chemistry requires the study of new effective and preparative strategies for the design and modification of the thiophene scaffold. Such synthetic strategies include the use of Meerwein reaction products as bifunctional building blocks. The efficiency of previously undescribed Meerwein reaction products, nitriles and methyl esters of 3-aryl-2-bromo-2-chloropropanoic acid and 3-aryl-2-bromo-2-methyl-3 chloropropanitriles, as C-3 synthons for the construction of 2-functionalized 3-amino- and 3-hydroxy-5-aryl(hetaryl)thiophenes under Thorpe-Ziegler and Fisselman reactions is shown. The universality of this approach to the formation of the thiophene cycle using a number of functionalized thiols and make it possible to introduce various aryl substituents in the 5 position of thiophene, which are not available sometimes when using other methods is shown. The efficiency and convenience of using the obtained compounds as synthetic tool for the construction of target thiophene-containing systems, in particular, thieno[3,2 b]pyridine-5,7(4H,6H)diones, thieno[3,4d]thiazole-2-amines, thieno[3,2 d][1,2,3]triazine-4-(3H)-ones and 3-hydroxy-5-aryl-2-R-thieno[3,2-b]furans was proved.