Regioselective ring opening of 2,2-dicyanooxiranes by 1,3-dinucleophiles in the presence of Lewis acids such as bismuth(III) nitrate pentahydrate [Bi(NO3)3·5H2O] and zirconium(IV) chloride (ZrCl4)

Abstract

Bismuth(III) nitrate pentahydrate [Bi(NO 3 ) 3 Á5H 2 O] or zirconium(IV) chloride (ZrCl 4 ) has been shown to catalyze nucleophilic ring opening of 2,2-dicyanooxiranes along with ring closure by 1,3-dinucleophiles such as 1H-1,3-benzimidazole-2-thiol, 5-phenyl-4H-1,2,4-triazole-3-thiol, and thioureas. These reactions led to efficient synthesis of heterocyclic compounds condensed with benzimidazole or triazole derivatives. The used catalysts are inexpensive, highly efficient, and reusable for opening of epoxides with 1,3-dinucleophiles at ambient temperature, with excellent regioselectivity.

1,2,4-Triazole Derivatives in Medicine and Pharmacy and Application Prospects

“…Based on the results of virtual screening, the authors [4] concluded that thiazolyl-triazoleylidenhydrazide with a hydroxyphenyl substitute is the best candidate for a leader compound that exceeds the action of ciprofloxacin [4]. The authors [5] showed that Bi(NO3)3 • 5H2O or ZrCl4 catalyzed the opening of the nucleophilic ring of dicyanooxyrans together with 5-thio-1,2,4-triazole-3-phenyl. The catalysts are inexpensive, highly efficient, and can be used repeatedly (Fig.…”