Polyoxometalate-Driven Ease Conversion of Valuable Furfural to -,-4,5-Diaminocyclopenten-2-ones.

We investigated the catalytic efficacy of silicotungstic acid (HSiWO) polyoxometalate (POM) toward the reaction between furfural and amines that selectively yields -,-4,5-substituted-diaminocyclopenten-2-ones (-DACPs). HSiWO facilitates the synthesis of a library of -DACPs with loadings as low as 0.05 mol %, in open air, without additives, in short times and good to high isolated yields. The protocol was applied to secondary amines as well as to aromatic primary amines with p higher than ca. 9. The present catalytic synthetic protocol has an extended substrate scope with high yields and represents, to the best of our knowledge, the first polyoxometalate-driven paradigm as an efficient method to produce cyclopentanone frameworks under mild reaction conditions.