Zr-Based MOF-808 as Meerwein–Ponndorf–Verley Reduction Catalyst for Challenging Carbonyl Compounds

Abstract

Abstract:In the fine chemical industry, transfer hydrogenation of carbonyl compounds is an important route to selectively form the corresponding allyl alcohol. The Meerwein-Ponndorf-Verley reduction (MPV) is catalyzed by a Lewis acid catalyst and easily oxidizable alcohols serve as hydrogen donor. We successfully used the Zr-based metal-organic framework (MOF) MOF-808-P as MPV-catalyst with isopropyl alcohol as solvent and hydride donor. After only 2 h, 99% yield of cinnamyl alcohol was obtained. The highly active MOF-808-P is also a good catalyst for the selective reduction of more challenging substrates such as R-carvone and β-ionone. Two strategies were successfully used to shift the equilibrium towards the desired allylic alcohol products: (1) evaporation of formed acetone and (2) the use of the more strongly reducing 1-indanol. Carveol yield was increased to >70%. These results highlight the great potential of this recently discovered Zr-MOF as a chemically and thermally stable catalyst.

Catalytic Transfer Hydrogenation of Biomass‐Derived Carbonyls over Hafnium‐Based Metal–Organic Frameworks

“…This strategy becomes even more interesting if a heterogeneous catalyst is utilized featuring non‐precious metals and providing effective performance resulting in a cost‐effective alternative method to the use of molecular H 2 or formic acid. Therefore, a variety of catalytic non‐precious metal‐containing solids have been reported for this reaction, ranging from metal oxides such as ZrO 2 to crystalline porous materials including zeolites such as Zr‐Beta, Sn‐Beta, and metal–organic frameworks such as UiO‐66‐Zr, Zr‐MOF‐808, and Zr‐MOF‐808‐P . As for hafnium‐based heterogeneous catalysts, an organometallic hafnium complex is reported to be immobilized on MCM‐type materials—mesoporous siliceous materials with mono‐ or tridimensional pore structure—and used for the selective hydrogen transfer reduction of α,β‐unsaturated ketones .…”

Selective Reduction of Ketones and Aldehydes in Continuous-Flow Microreactor—Kinetic Studies

“…The Inexpensive and non-toxic hydrogen donors and catalysts, mild reaction conditions, and exceptional chemoselectivity render this method of reduction favorable over alternatives. Among many active species, such as Zr [1,2], Al [3,4], Mg [3,5], and B [6,7], which are considered to be active catalysts for MPV reduction, zirconium has been shown to be one of the most promising. In the literature, batch processes are predominantly described with the use of numerous catalysts, e.g., homogeneous alkoxides [8,9], zeolites [10,11], mesoporous sieves [12][13][14], and hydrotalcite [15].…”

“…It was due to excellent mixing and mass transfer conditions, offered by innovative monolithic microreactor characterized by high surface-to-volume ratios. Application of the proposed 2 in the flow process (data form literature), 3 in the batch process (data form literature); 4 nerol/geraniol; * data for the 4-cm-long microreactor.…”

Direct Transformation of HMF into 2,5‐Diformylfuran and 2,5‐Dihydroxymethylfuran without an External Oxidant or Reductant

“…Experiments showed that the HMF conversion gradually increased from 19.3 to 26.1 % if the initial HMF concentration was simultaneously increased from 0.1 to 1.0 mol L −1 (Table , entries 1–4). The higher initial HMF concentration causes the formation of more DHMF precipitate, inducing an equilibrium shift of the MPVO reaction of HMF towards DFF and DHMF . The difference in solubility of DHMF and DFF in acetonitrile not only permits the equilibrium to shift but also provides a promising protocol for the crude separation of DHMF from DFF (Figure S3 A and B).…”