Zinc Tetrafluoroborate-Mediated Ring Expansion of trans-Aziridine-2-carboxylates to cis-2-Iminothiazolidines and cis-Thiazolidine-2-iminium Tetrafluoroborates and Evaluation of Antimicrobial Activity

Cis-2-iminothiazolidines and cis-thiazolidine-2-iminiumtetrafluoroborates were successfullyproducedfrom trans-N-alkyl aziridine-2-carboxylatesand phenyl/alkyl isothiocyanates mediated by zinc tetrafluoroboratein refluxing DCE. Reactions were performed via a complete regio- andstereoselective process to give the title iminothiazolidines and cis-thiazolidine-2-iminium salts in moderate to good yields(35 to 82%) with a wide substrate scope. In addition, the antibacterialactivity evaluation of these compounds, as well as the minimum inhibitoryconcentration (MIC) determination, revealed that only four cis-thiazolidine-2-iminium salts showed growth inhibitionagainst Bacillus cereus.

Automated summary

Cis-2-iminothiazolidines and cis-thiazolidine-2-iminiumtetrafluoroborates were successfully synthesized from trans-N-alkyl aziridine-2-carboxylates and phenyl/alkyl isothiocyanates mediated by zinc tetrafluoroborate in refluxing DCE. The reactions showed complete regio- and stereoselectivity, yielding moderate to good amounts (35-82%) with a wide range of substrates.