New catalytic method for the synthesis of vitamins K

Matveev, K. I.; Жижина, Е. Г.; Odyakov, V. F.

doi:10.1007/bf02075833

“…This type of electron transfer oxidation was further investigated in a careful mechanistic investigation with similar catalysts [110]. An interesting extension of this work is the oxidation of 2-methyl-1-naphthol to 2-methyl-1,4naphthaquinone (Vitamin K 3 , menadione) in fairly high selectivity (about 83% at atmospheric O 2 ) [111]. This work could lead to a new environmentally favorable process to replace the stoichiometric CrO 3 oxidation of 2-methylnaphthalene used today.…”

Section: Oxidation With Molecular Oxygenmentioning

confidence: 88%

Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates

Neumann

¹

2010

Modern Oxidation Methods

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j315 and recycling of the catalyst. Following a short introduction to polyoxometalates, their structure and general properties, the major parts of this review deal with three different types of oxidants: (i) mono-oxygen donors, (ii) peroxides and (iii) molecular oxygen. Finally, various systems for catalyst engineering designed to aid in catalyst manipulation, recovery and recycling are discussed. Polyoxometalates (POMs)Research applications of polyoxometalates have over the past two decades become very apparent and important, as reflected by the recent publication of a special volume of Chemical Reviews [1] devoted to these compounds. The diversity of research in the polyoxometalate area is significant and includes their application in many fields, including structural chemistry, analytical chemistry, surface chemistry, medicine, electrochemistry, and photochemistry. However, the most extensive research on the application of polyoxometalates appears to have been in the area of catalysis, where their use as Brønsted acid catalysts and oxidation catalysts has been going on since the late 1970s. Research published over the past decade or two has firmly established the significant potential of polyoxometalates as homogeneous oxidation catalysts. Through the development of novel ideas and concepts, polyoxometalates have been shown to have significant diversity of activity and mechanism that in the future may lead to important practical applications. In recent years, a number of excellent general reviews on the subject of catalysis by polyoxometalates have already been published [2], and while some repetition is inevitable we will attempt to keep the redundancy in the present review to a minimum.A basic premise behind the use of polyoxometalates in oxidation chemistry is the fact that these compounds are oxidatively stable. In fact, as a class of compounds they are thermally stable generally to at least 350-450 C in the presence of molecular oxygen. This, a priori, leads to the conclusion that for practical purposes polyoxometalates would have distinct advantages over widely investigated organometallic compounds that are vulnerable to decomposition due to oxidation of the ligand bound to the metal center. Polyoxometalates, previously also called heteropolyanions, are oligooxide clusters of discrete structure with a general formula [X x M m O y ] qÀ (x m) where X is defined as the heteroatom and M are the addenda atoms. The addenda atoms are usually either molybdenum or tungsten in their highest oxidation state, 6 þ , while the heteroatom can be any number of elements, transition metals and main group elements phosphorus and silicon being the most common heteroatoms. A most basic polyoxometalate, [XM 12 O 40 ] qÀ where (X ¼ P, Si, etc.; M ¼ W, Mo), is that possessing the Keggin structure, Figure 9.1. Such Keggin type polyoxometalates, commonly available in their protic form, are significant for catalysis only as Brønsted acid catalysts.However, since polyoxometalate synthesis is normally carried out in water by mixing ...

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“…It should be mentioned within this context that Wackertype oxidations can also be performed with halide-free systems [14,15], by using palladium salts in combination with heteropolyacids. The advantages of this halide-free process are clear: apart from the absence of halidecontaining byproducts, the corrosion problems associated with halide-containing catalyst solutions are largely reduced.…”

Section: History Of the Process And Overview Of Related Technologiesmentioning

confidence: 99%

Acetoxylation of Ethylene

Schunk

¹

,

Oliveira

²

2008

Handbook of Heterogeneous Catalysis

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The sections in this article are History of the Process and Overview of Related Technologies The B ayer Process Early Developments: The Liquid Phase Route to Vinyl Acetate The B ayer Process: Process and Catalyst A Description of the B ayer Process B Description of the Catalyst Employed in the B ayer Process Steps Towards Process Intensification: The BP Processes A Schematic Overview of the Fluid‐Bed BP Process to Vinyl Acetate The Catalyst System Used in the Fluid‐Bed BP Process to Vinyl Acetate One Step Further: Vinyl Acetate from Ethylene or Ethane in an Integrated Process Scheme A Structural Insight into the Catalyst System Palladium Catalysts Palladium–Gold Catalysts Palladium Catalysts in Related Acetoxylation Reactions A Mechanistic Insight into the Gas‐Phase Acetoxylation of Ethylene Acetoxylation of Ethylene in Supported Liquid Phase Rate Laws for the Acetoxylation of Ethylene Reaction Mechanisms for the Acetoxylation of Ethylene in the Gas Phase Beyond Ethylene Acetoxylation: Reaction Mechanisms for the Acetoxylation of Related Substrates Mechanisms Effective in the Homogeneous Liquid‐Phase Acetoxylation of Ethylene Conclusions and Outlook Acknowledgments

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“…[7] However, the Wacker process requires large amounts of chloride ions and acid to maintain a catalytic cycle; therefore, the system is highly corrosive and often causes the formation of chlorinated side products. Although systems with various alternative halide-free co-catalysts, such as CuA C H T U N G T R E N N U N G (OAc) 2 , heteropoly acids, nitrates, and benzoquinone, have been intensively studied in attempts to reduce the environmental impact of these processes, [8][9][10][11][12][13][14] the reoxidation of palladium(0) during the catalytic cycle under more friendly conditions remains a critical challenge.…”

Section: Introductionmentioning

confidence: 99%

Palladium‐Catalyzed Aerobic Oxidation of Naturally Occurring Allylbenzenes as a Route to Valuable Fragrance and Pharmaceutical Compounds

Parreira

¹

,

Menini

²

,

Santos

³

et al. 2010

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A palladium-catalyzed, aerobic oxidation of naturally occurring allylbenzenes, i.e., eugenol, methyleugenol, safrole, and estragole, in dimethyl-A C H T U N G T R E N N U N G acetamide/water solutions under mild conditions has been developed, in which palladium(II) chloride is used in the absence of co-catalysts or special stabilizing ligands as the sole and recyclable catalyst. Methyl ketones that are important for the flavour and pharmaceutical industries have been obtained in good to excellent yields with low catalyst loadings (1-2 mol%) and high average turnover frequencies. This simple catalytic method represents an ecologically benign and economically attractive route to industrially valuable compounds starting from renewable substrates easily available from essential oils.

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New catalytic method for the synthesis of vitamins K

Cited by 31 publications

References 2 publications

Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates

Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates

Acetoxylation of Ethylene

Palladium‐Catalyzed Aerobic Oxidation of Naturally Occurring Allylbenzenes as a Route to Valuable Fragrance and Pharmaceutical Compounds

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