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

Abstract

We investigated the catalytic efficacy of silicotungstic acid (H4SiW12O40) polyoxometalate (POM) toward the reaction between furfural and amines that selectively yields trans-N,N-4,5-substituted-diaminocyclopenten-2-ones (trans-DACPs). H4SiW12O40 facilitates the synthesis of a library of trans-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 pK b 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.

Simple Synthetic Approach to N-(Pyridin-2-yl)imidates from Nitrostyrenes and 2-Aminopyridines via the N-(Pyridin-2-yl)iminonitriles as Intermediates

“…Given the importance of this type of transformation and in terms of sustainability, the use of ambient and more eco-friendly heterogeneous conditions for the synthesis of substituted imidates continues to be a long-standing goal of chemical research. In light of our ongoing research directions for developing sustainable processes to construct N-heterocyclic organic molecules of high biological interest [25][26][27][28][29][30], herein we report the synthesis of a library of substituted N-(pyridin-2-yl)imidates from the corresponding N-(pyridin-2-yl)iminonitriles in the presence of Cs 2 CO 3 and alcoholic media at ambient conditions (Scheme 1). Subsequently, the starting N-(pyridin-2-yl)iminonitriles were synthesized via a new heterogeneous catalytic process using Al 2 O 3 in 1,2-dichloroethane (DCE) (Scheme 1).…”