Discussion Addendum for: Synthesis of Substituted Indazoles via [3 + 2] Cycloaddition of Benzyne and Diazo Compounds

Abstract This chapter presents the step by step procedure for the synthesis of substituted indazoles via [3 + 2] cycloaddition of benzyne and diazo compounds. It covers the reaction of benzynes with monosubstituted diazo derivatives, reaction of benzynes with disubstituted diazo derivatives, and reaction of benzynes with α‐diazo phosphonates. Mechanistic investigations conducted by Ramana suggest that loss of the phosphonate group from the OBR occurs within two hours under the reaction conditions and it provides a plausible mechanistic explanation for the reaction's outcome. The field of benzyne‐mediated transformations has continued its growth. More and more procedures have appeared in the literature that allow the conversion of readily available starting materials into much more complex molecules, particularly, nitrogen‐containing heterocycles.