Metal Organic Frameworks as Solid Acid Catalysts for Acetalization of Aldehydes with Methanol

Abstract

Room temperature acetalization of aldehydes with methanol has been carried out using metal organic frameworks (MOFs) as solid heterogeneous catalysts. Of the MOFs tested, a copper-containing MOF [Cu 3

Chemical instability of Cu3(BTC)2 by reaction with thiols

“…As a part of our ongoing investigations on the performance of MOFs as heterogeneous catalysts, [4,9,10,12] we were interested in studying the formation of C-S bond through the nucleophilic addition of thiophenol to aryl halides using Cu 3 (BTC) 2 as a catalyst. It has been already reported in the literature that Cu(II) ions catalyze this particular reaction with very good yield and selectivity.…”

“…[3] Since its origin many research works have been carried out with this MOF. For instance, Cu 3 (BTC) 2 have been used widely as heterogeneous catalysts in acetalization of aldehydes with methanol, [4] quinoline synthesis, [5] -pinene oxide rearrangement, [6] trimethylsilylazide addition to carbonyl compounds, [7] oxidation of benzylic compounds with t-butylhydroperoxide, [8] ring opening of epoxides with methanol, [9] alkylation of amines with dimethyl carbonate, [10] and cycloaddition of phenylacetylene with benzyl azide among other reactions. [11] Considering that the use of MOFs as solid catalysts is a field of growing importance and the ample use of Cu 3 (BTC) 2 as solid catalysts, it is of interest to delineate the scope and conditions in which this material can be used in catalysis.…”

Highly Efficient Acetalization and Ketalization Catalyzed by Cobaloxime under Solvent-Free Condition

“…It was interesting to find that seven-membered cyclic ketals could be easily generated (entries [13][14][15]. Although the reaction of acetophenone with butane-1,4-diol took place slowly, the ketalization of butane-1,4-diol with cyclohexanone, and benzaldehyde achieved moderate to excellent yields of the corresponding seven-membered cyclic ketals.…”

“…However, those methods suffered from several drawbacks, such as corrosion, tedious work-up, environmental pollution and non-recoverability of catalysts. To solve those problems, a variety of solid acidic catalysts, which were prepared by immobilization of acidic catalysts on various inorganic or organic supporters, have been investigated [11][12][13][14][15][16][17][18][19][20]. Furthermore, many acid or Lewis acid-functionalized ionic liquids were used for acetalization or ketalization [21][22][23][24].…”

Cross-dehydrogenative coupling of coumarins with Csp3–H bonds using an iron–organic framework as a productive heterogeneous catalyst

“…Indeed, Dhakshinamoorthy et al previously pointed out that the interaction of pyridine as a base with the Lewis acid sites in metal-organic frameworks resulted in the deactivation of the MOF-based catalysts. 36 Therefore, the free coordination iron sites in the VNU-20 framework should be responsible for the catalytic coupling reaction, and the deactivation of these sites would terminate the transformation. From these observations and previous reports, 7,8,10 a plausible mechanism was suggested (Scheme 2).…”