Recent Advances in Polyoxometalate-Catalyzed Reactions

Recent advances in the Suzuki–Miyaura cross-coupling reaction using efficient catalysts in eco-friendly media

The chemistry of vanadium has seen remarkable activity in the past 50 years. In the present review, reactions catalyzed by homogeneous and supported vanadium complexes from 2008 to 2018 are summarized and discussed. Particular attention is given to mechanistic and kinetics studies of vanadium-catalyzed reactions including oxidations of alkanes, alkenes, arenes, alcohols, aldehydes, ketones, and sulfur species, as well as oxidative C–C and C–O bond cleavage, carbon–carbon bond formation, deoxydehydration, haloperoxidase, cyanation, hydrogenation, dehydrogenation, ring-opening metathesis polymerization, and oxo/imido heterometathesis. Additionally, insights into heterogeneous vanadium catalysis are provided when parallels can be drawn from the homogeneous literature.

Catalytic Applications of Vanadium: A Mechanistic Perspective.

Oxovanadium complexes in catalytic oxidations

Polyoxometalates (POMs) are molecular metal-oxide anions applied in energy conversion and storage, manipulation of biomolecules, catalysis, as well as materials design and assembly. Although often overlooked, the interplay of intrinsically anionic POMs with organic and inorganic cations is crucial to control POM self-assembly, stabilization, solubility, and function. Beyond simple alkali metals and ammonium, chemically diverse cations including dendrimers, polyvalent metals, metal complexes, amphiphiles, and alkaloids allow tailoring properties for known applications, and those yet to be discovered. This review provides an overview of fundamental POM-cation interactions in solution, the resulting solid-state compounds, and behavior and properties that emerge from these POM-cation interactions. We will explore how application-inspired research has exploited cation-controlled design to discover new POM materials, which in turn has led to the quest for fundamental understanding of POM-cation interactions.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.201905600

Beyond Charge Balance: Counter‐Cations in Polyoxometalate Chemistry

https://www.rsc.org/suppdata/cy/c3/c3cy00717k/c3cy00717k.pdf

Keggin type transition metal substituted phosphomolybdates: heterogeneous catalysts for selective aerobic oxidation of alcohols and alkenes under solvent free condition

Mono-transition-metal-substituted phosphomolybdates, PMo11M (M = Co, Mn, Ni), were synthesized and characterized by various physicochemical techniques. They were efficiently used for liquid-phase nonsolvent oxidation of styrene under mild reaction conditions. It was found that all of the catalysts are efficient in achieving higher conversions with high turnover numbers and are selective toward benzaldehyde. A detailed kinetic study was also carried out. Although all of the catalysts are homogeneous under the present oxidation conditions, they were regenerated and reused for up to two cycles.

Transition-Metal-Substituted Phosphomolybdates: Catalytic and Kinetic Study for Liquid-Phase Oxidation of Styrene

Selective green oxidation of alcohols and alkenes with molecular oxygen using supported undecamolybdophosphate under solvent free condition

The Keggin-type cesium salt of transition metal-substituted phosphomolybdates, Cs5[PCo(H2O)Mo11O39] · 6H2O (1) and Cs5[PMn(H2O)Mo11O39] · 6H2O (2), were synthesized from commercially available H3PMo12O40. The compounds were characterized by thermal, structural, and spectroscopic techniques. X-ray structural analysis reveals that, in these isostructural disordered compounds, the transition metal (Co/Mn) and Mo atoms are distributed over 12 positions. The presence of Co/Mn atoms was confirmed by powder XRD, FT-IR, DR-UV-Vis, ESR, and 31P NMR studies.

Soyeb Pathan

Papers

Keggin type transition metal substituted phosphomolybdates: heterogeneous catalysts for selective aerobic oxidation of alcohols and alkenes under solvent free condition

Transition-Metal-Substituted Phosphomolybdates: Catalytic and Kinetic Study for Liquid-Phase Oxidation of Styrene

Selective green oxidation of alcohols and alkenes with molecular oxygen using supported undecamolybdophosphate under solvent free condition

Keggin-type cesium salt of first series transition metal-substituted phosphomolybdates: one-pot easy synthesis, structural, and spectral analysis

Functionalized SBA-15 for controlled release of poorly soluble drug, Erythromycin