Recent advances in <i>tert</i> -butyl nitrite-mediated nitration cyclization/spirocyclization reactions

Nitro-functionalized compounds and their derivatives have attracted considerable attention because of their synthetic value/special biological activities. Direct cascade cyclization reactions of unsaturated hydrocarbons with nitro-reagents are of particular interest to the chemical community because these strategies provide opportunities for the introduction of important nitro groups onto target frameworks with high step and atom economy. In recent years, <i>tert</i>-butyl nitrite (TBN) has shown considerable promise in cascade cyclization reactions due to its distinctive chemical properties, offering a novel platform for the efficient and diverse synthesis of heterocyclic compounds. This review highlights recent advances in this field, categorizing the discussion by reaction substrates and featuring representative examples and mechanisms. It also addresses the current challenges and future research directions.