Synthesis and Antimicrobial Evaluation of Novel Chiral 2-Amino-4,5,6,7-tetrahydrothieno[2,3-c]pyridine Derivatives

Trends in the Synthesis of Antimicrobial Derivatives by using the Gewald, Strecker, and Groebke-Blackburn-Bienaymé (GBB) Reactions

BACKGROUND

Multicomponent reactions are highly useful in synthesizing natural products and bioactive molecules. Out of several MCRs, although utilized widely, some remain neglected in review articles. The Gewald and Groebke-Blackburn-Bienaymé (GBB) reactions are two such reactions. This comprehensive review assimilates applications of Gewald and Groebke-Blackburn- Bienayme reactions in synthesizing novel antimicrobial agents. It presents the antimicrobial properties of the synthesized molecules, providing an overview of their potential druggability.

OBJECTIVE

Developing novel antimicrobial agents is the need of the hour. Toward this objective, the scientific community is developing new methods for constructing novel architectures with potential antimicrobial properties. This review will showcase the usefulness of the Gewald, Strecker, and Groebke-Blackburn-Bienaymé (GBB) reactions in synthesizing antimicrobial molecules.

METHODS

The articles are searched by using the Sci-finder search tool and summarize the chemistry of their synthesis and antimicrobial evaluation of the molecules.

RESULTS

This review focuses on synthesizing antimicrobial molecules using the Gewald, Strecker, and Groebke-Blackburn-Bienaymé (GBB) reactions. The antimicrobial activities of the synthesized molecules are also summarized in tables.

CONCLUSION

This review will briefly overview the application of the Gewald, Strecker, and Groebke- Blackburn-Bienaymé (GBB) reactions in synthesizing novel antimicrobial molecules. It contains several molecules with promising activity against resistant and non-resistant microbial strains. These promising molecules could be studied further to develop novel antibiotics.

Thiophene-containing compounds with antimicrobial activity

Thiophene, as a member of the group of five-membered heterocycles containing one heteroatom, is one of the simplest heterocyclic systems. Many synthetic strategies allow the accurate positioning of various functionalities onto the thiophene ring. This review provides a comprehensive, systematic and detailed account of the developments in the field of antimicrobial compounds featuring at least one thiophene ring in their structure, over the last decade.

2-Amino-4,5-dihydrothiophene-3-carbonitriles: A New Synthesis, Quantum Chemical Studies, and Mannich-Type Reactions Leading to New Hexahydrothieno[2,3-d]pyrimidines

trans-2-Amino-4-aryl-5-benzoyl-4,5-dihydrothiophene-3-carbonitriles were prepared either by the reaction of 3-aryl-2-cyanothioacrylamides with α-thiocyanatoacetophenone or by the Michael-type addition of cyanothioacetamide to α-bromochalcones followed by intramolecular cyclization. The mechanism of the first reaction was studied using high-level quantum chemical calculations. Density functional theory (DFT) studies were carried out to determine the mechanism of the first reaction. A new approach toward the construction of the thieno[2,3-d]pyrimidine core system was demonstrated by the reaction of the prepared dihydrothiophenes with HCHO and RNH2 under noncatalyzed Mannich conditions.