Events

This presentation is dedicated to the modification of the Biginelli reaction for the synthesis of trisubstituted imidazoles from readily available acyclic N, N-bis-nucleophiles, 2-oxoaldehydes and 1,3-dicarbonyl compounds. Most of the synthesized products were successfully used in the subsequent photocyclization reaction to form structurally interesting polycyclic molecules. The replacement of N, N-bis-nucleophiles to ketenaminals allowed to carry out a similar process in a chemoselective manner to obtain a diverse library of fused polyheterocycles including pyrrolo[2,1-b]thiazoles, pyrrolo[1,2-a]imidazoles and imidazo[1,2-a] quinolines.

In various physiological and biological functions, bioactive materials as a key technique or procedure hold promise for the achievement of therapeutic effects in animals or humans. Recently, due to the outstanding features of biomaterials, more attention has been concerned to their applications in industry and medicine.

Acyl(imidoyl)ketenes are highly reactive heterocumulenes that enable diversity-oriented synthesis of various drug-like heterocycles. Such ketenes, bearing heterocyclic substituents, afford angularly fused pyridin-2(1H)-ones in their [4+2]-cyclodimerization reactions. We have utilized this property for the development of a new synthetic approach to pharmaceutically interesting pyrido[2,1-b][1,3]benzothiazol-1-ones via the [4+2]-cyclodimerization of acyl(1,3-benzothiazol-2-yl)ketenes generated in situ. The thermal behaviors of 3-aroylpyrrolo[2,1-c][1,4]benzothiazine-1,2,4-triones and 3-benzoylpyrrolo[2,1-b][1,3]benzothiazole-1,2-dione (two new types of [e]-fused 1H-pyrrole-2,3-diones) have been studied by thermal analysis and HPLC to elucidate their capability to be a source of acyl(1,3-benzothiazol-2-yl)ketenes. As a result, we have found that only 3-aroylpyrrolo[2,1-c][1,4]benzothiazine-1,2,4-triones are suitable for this. The experimental results are supplemented with computational DFT studies of the possible reaction mechanisms that demonstrate that thermolysis of 3-aroylpyrrolo[2,1-c][1,4]benzothiazine-1,2,4-triones proceeds through an unprecedented cascade of two thermal decarbonylations.

The isocyanide is an interesting and unique functional group in organic chemistry. The carbon atom in isocyanide can act as a nucleophile, as an electrophile, as a carbine involved in formal [1 + 4] cycloaddition, and as a radical acceptor to form imidoyl radical reaction intermediates. Its nature of the isocyanide makes it capable reacting with different strategies with various reactants under reaction conditions. As a result, the reaction of isocyanide were usually carried out via unpredictable way and obtained unexpected products. In this presentation, numerous unexpected isocyanide-based multicomponent reactions from our research group will be presented.

Recently, the preparation of neoteric functional materials with multicomponent reactions strategy has interestingly enhanced the union of materials chemistry. The main components (amine, carboxylic, or carbonyl groups) of MCRs are usually present in the materials structure or can be easily announced on their surfaces. Hence, materials can contribute in MCRs for the greatly talented modified/functionalized materials synthesis. In this presentation, the design and functionalization/modification of nano-materials and natural polymers with application in the catalytically chemical transformations and in the CO2 fixation will be presented.