[3+2]-Cycloadditions of nitrilimines with heteroaryl thioketones

Abstract

The in situ generated nitrilimines are trapped efficiently with heteroaryl thioketones bearing thiophen-2-yl or selenophen-2-yl substituents. The exclusive products observed in these reactions are 2,3-dihydro-1,3,4-thiadiazoles formed via regioselective [3+2]-cycloaddition. Competitive head-to-tail dimerization of the intermediate 1,3-dipoles was not observed in any of the studied reactions.

GRAPHICAL ABSTRACT

KEYWORDS:

• [3+2]-Cycloadditions
• thioketones
• nitrilimines
• 1,3,4-thiadiazoles
• X-ray crystallography

Acknowledgement

Skillful performance of elemental analysis of all new compounds by Ms Agnieszka Cieślińska and Ms Hanna Jatczak (University of Łódź) is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

G. M., K. U., and H. H. thank the National Science Center (Cracow, Poland) for generous financial support [grant Maestro-3 (Dec-2012/06/A/ST5/00219)]. K. A. thanks the National Research Centre-Egypt for supporting the work.