RECENT SYNTHETIC APPROACHES TO 1 H - AND 2 H -INDAZOLES
The work summarizes latest strategies for the synthesis of 1H- and 2H-indazoles published during the last five years. The strategies include transition metal catalyzed reactions, reductive cyclization reactions, and synthesis of 2H-indazoles via consecutive formation of C–N and N–N bonds without catalyst and solvent from 2-azidobenzaldehydes and amines. This review article gives a brief outline of optimized synthetic schemes with relevant examples.