Advances in the Bestmann–Ohira Reagent–Assisted Regioselective Synthesis of Substituted Pyrazoles, Triazoles, and Oxazoles

Abstract

The Bestmann–Ohira reagent serves as a versatile platform for the regioselective construction of pyrazoles, triazoles, and oxazoles via a cycloaddition reaction and multicomponent reaction. In this review, we have summarized the most significant advances in the Bestmann–Ohira reagent (BOR)–assisted construction of functionalized five–membered heterocycles reported in the literature up to 2012.

GRAPHICAL ABSTRACT

Keywords:

• Bestmann–Ohira reagent
• click chemistry
• cycloaddition
• multicomponent reactions N-heterocycles
• oxazole
• phosphonylpyrazole
• triazole

ACKNOWLEDGMENTS

C. B. is thankful to the University Grant Commission, New Delhi, India, for providing financial support in the form of teacher fellowship. S. N. thanks the Department of Science and Technology, government of India, for providing Fast Track Grant No. 061/2011.