Chiral and amine groups functionalized polyoxometalate-based metal-organic frameworks for synergic catalysis in aldol and Knoevenagel condensations

• Published in: Molecular catalysis Vol. 458; pp. 83 - 88
• Main Authors: Xing, Songzhu, Li, Jie, Niu, Guiqin, Han, Qiuxia, Zhang, Jingjing, Liu, Hongling
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2018
• Subjects: Aldol condensation; Catalysis; Chiral metal-organic frameworks; Knoevenagel condensation; Polyoxometalate; Synergic; Polyoxometalate; Synergic; Chiral metal-organic frameworks; Catalysis; Knoevenagel condensation; Aldol condensation
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2018.08.011

A pair of new enantiomers NH2-Co-PYIs consisting of Lewis acid and Lewis basic were successfully synthesized, which act as bifunctional catalysts displaying high catalytic activity and selectivity in the synergic catalysis Aldol and Knoevenagel condensation. [Display omitted] •Two enantiomers NH2-Co-PYIs were synthesized by introducing the Lewis acid and base catalytic groups into one single MOF.•NH2-Co-PYIs have excellent properties of unambiguous crystalline structure, economic chemical reagents and highly stability.•The orderly distributed and spatial matching of multiple catalytic active sites enhanced their reactivity through a synergistic cooperation.•NH2-Co-PYIs display high catalytic activity and selectivity in Aldol and Knoevenagel condensation under mild conditions. Recently, great interest is focused on developing synergic catalysis that the reactants are bound and oriented at two different centers. In this context, by simultaneously introducing Lewis acid and Lewis basic into a polyoxometalate based metal-organic framework, a pair of enantiomer NH2-Co-PYIs were achieved and characterized by IR, PXRD, CD, TGA. NH2-Co-PYIs displayed high catalytic activity and selectivity in synergic catalysis Aldol/Knoevenagel condensation as bifunctional catalysts. Multiple catalytic active sites were orderly distributed and spatial matching, which would be a powerful approach to increase the stability and the corresponding functions and to enhance their reactivity through a synergistic cooperation between different catalysis sites.