New Three-Component Bicyclization Leading to Densely Functionalized Pyrazolo[3,4-]thiazolo[3,2-]pyrimidines.

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