tert-Butyl Nitrite-Induced Cyclization Reactions in the Construction of Heterocyclic Compounds

Heterocyclic compounds are prominent in the field of organic chemistry. They have numerous applications, such as medicinal chemistry, natural products, biological activity, agrochemicals, dyes, and the pharmaceutical industry. The t-BuONO reagent has been utilized in synthetic organic chemistry to synthesize various heterocyclic compounds in recent years. Due to the properties of tert-Butyl nitrite as a mild, cost-effective, easy-to-handle, and environmentally friendly reagent, it is widely utilized. This reagent serves as a source of oxygen, nitrogen, nitric oxide, and nitrous oxide in organic reactions and is used as a co-catalyst or catalyst. tert-Butyl nitrite is employed in various reactions, including oxidation, radical initiation, and diazotization. These reactions facilitate cyclization processes like 5-exo-dig, 5-exo-trig, [3+2] cycloaddition, [3+2] dimerization, and 1,3-dipolar cycloaddition. This reactivity supports the construction of new types of heterocyclic compounds through simple synthetic procedures. In this review, we discuss the use of tert-Butyl nitrite in the synthesis of various heterocyclic compounds, providing detailed mechanisms and representative examples of substrate scope.