A novel three-component bicyclization for the efficient synthesis of densely functionalized pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidines has been established from readily accessible aryl aldehydes, α-thiocyanate ketones and pyrazol-5-amines. The reaction pathway involves nucleophilic addition/5-exo-trig /6-endo-trig bicyclization sequence, resulting in continuous multiple bond-forming events including C-N and C-C bonds to rapidly a molecular complexity.
Keywords: Bicyclization; Microwave Heating; Multicomponent Reactions; Pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidines; α-thiocyanate ketones.