Biginelli Reaction: A Green Perspective

The Biginelli Reaction is a one-pot acid catalysed cyclocondensation of � -keto ester, urea and aromatic aldehyde which leads to the synthesis of functionalised 3,4-dihydro-2(H)-pyrimidinones (DHPMs). This three-component reaction for the synthesis of dihydro- pyrimidinone and corresponding dihydropyrimidinethiones has now been known for more than a century since first reported in 1893. Owing to the increasing use of Green technology approach, due to its various merits over Classical methodology and as a need for sus- tainable Chemistry, this reaction has received renewed interest for preparing DHPMs in an environmentally thoughtful manner with im- proved yields. The classical reaction has been modified in the recent past by using various catalysts and several structural variants in dif- ferent solvents to synthesize large number of Biginelli type compounds. Also, these DHPMs (synthetic and natural) possess a wide range of pharmacological activities. We hereby wish to compile, in this present review, the literature available methods related to large number of Biginelli type compounds synthesized using eco-friendly technologies. This protocol couples the benefits of Biginelli reaction with that of greener approach for organic transformations, thus facilitating efficient synthesis of bioactive compounds in environmentally be- nign way.