Metal free green protocol for the synthesis of bis-spiro piperidine and pyrimidine derivatives

摘要

A highly efficient one-pot three-component synthesis of bis-spiro piperidine and pyrimidine derivatives has been reported by performing the reaction of formaldehyde, aromatic aniline and 1,3-dicarbonyl compounds. This reaction was carried out at room temperature in 2,2,2-trifluoroethanol (TFE) as a recyclable reaction medium under the metal free condition. The strong hydrogen donor ability and acidic property of TFE plays a key role in accelerating the rate of reaction and initiates the reaction smoothly. The advantageous features of this method are a mild reaction condition, no column chromatographic purification, and high yield of products and recyclability of TFE.