1,3-dipolar cycloadditions in aqueous media

1,3-Dipolar cycloadditions in aqueous media represents a useful, non conventional protocol in the synthesis of a variety of five-membered heterocycles. In addition, water as the solvent may significantly enhance cycloaddition rates and/or stereoslectivities. The literature data on this subject are reviewed in a systematic way, with an emphasis to improvements with respect to cycloadditions performed in the usual, non-aqueous conditions.