Synthesis of various heterocyclic compounds via multi-component reactions in water

Due to special effects of water such as abundant, environmentally benign, hydrogen bonding in the transition state and high cohesive energy density as well as negative activation volume; the use of water as a green solvent is emphasized in green chemical processes. Heterocyclic compounds play an important role in the treatment of many diseases and also are effective in biological processes. Multi-component reactions are powerful synthetic methods in construction of new organic molecules because in these methods product is formed as one-pot and reduced number of reaction separation steps. For these reasons, the synthesis of heterocyclic systems using a simple multi-component approach in water is investigated greatly in the recent years. In this review, multi-component reactions that have been used for the synthesis of heterocyclic compounds in aqueous media during the last two decades are described.