Two inorganic–organic hybrid silver-polyoxometalates as reusable catalysts for one-pot synthesis of propargylamines via a three-component coupling reaction at room temperature. Issue 15 (30th March 2020)

• Record Type: Journal Article
• Authors: Dou, Ming-Yu; Huang, Xian-Qiang; Yang, Guo-Yu
• Is Part Of: CrystEngComm. Volume 22:Issue 15(2020)
• Page Start: 2642
• Page End: 2648
• Publication Date: 2020-03-30
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/d0ce00042f
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : Two silver-polyoxometalates [Ag3 L2 (DMSO)2 ][PW12 O40 ]·4DMSO (1 ) and [(Ag2 L2 )2 ][SiW12 O40 ]·10DMSO·2H2 O (2 ) are made and 1 shows good catalytic activities for three-component coupling reaction. Abstract : By the combination of Ag-complexes and Keggin POMs, two novel inorganic–organic silver–polyoxometalates hybrids, [Ag3 L2 (DMSO)2 ][PW12 O40 ]·4DMSO (1 ) and [(Ag2 L2 )2 ][SiW12 O40 ]·10DMSO·2H2 O (2 ) (L = 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine), were synthesized and characterized. Interestingly, the silver atoms in compound 1 are three-coordinated with the AgNO model; however, the Ag atoms of compound 2 were surrounded by four N atoms of the organic ligands and displayed a distorted tetrahedral configuration. Importantly, compound 1 showed high catalytic activities for the three-component coupling reaction of alkynes and secondary amines along with formaldehyde, which resulted in a series of propargylamine derivatives in higher yields (up to 99%). Furthermore, the Ag–POM catalyst was easily recovered by filtration and reused for three cycles without a significant loss in catalytic activity. A tentative mechanism is also proposed for this transformation.