[PDF] Palladium Catalyzed Aerobic Oxidation Of Alcohols eBook

Author : Maaz S. Ahmed
Publisher :
Page : 0 pages
File Size : 46,7 MB
Release : 2017
Category :
ISBN :

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Development of aerobic oxidation methods is of critical importance for the advancement of green chemistry, where the only byproduct produced is water. Recent work by our lab has produced an efficient Pd based heterogenous catalyst capable of preforming the aerobic oxidation of a wide spectrum of alcohols to either carboxylic acid or methyl ester. The well-defined catalyst PdBi0.35Te0.23/C (PBT/C) catalyst has been shown to can perform the aerobic oxidation of alcohols to carboxylic acids in basic conditions. Additionally, we explored this catalyst for a wide range of alcohols and probed the nature of the selectivity of PBT/C for methyl esterification over other side products. Finally, means by which the catalyst operates with respect to oxidation states of the three components, Pd, Bi, and Te, was probed. Carboxylic acids are an important functional group due to their prevalence in various pharmaceutically active agents, agrochemicals, and commodity scale chemicals. The well-defined catalyst PBT/C catalyst was discovered to be effective for the oxidation of a wide spectrum of alcohols to carboxylic acid. The demonstrated substrate scope and functional group tolerance are the widest reported for an aerobic heterogeneous catalyst. Additionally, the catalyst has been implemented in a packed bed reactor with quantitative yield of benzoic acid maintained throughout a two-day run. Biomass derived 5-(hydroxymethyl)furfural (HMF) is also oxidized to 2,5-furandicarboxylic acid (FDCA) in high yield. Exploration of PBT/C for the oxidative methyl esterification was found to exhibit exquisite selectivity for the initial oxidation of primary alcohol instead of methanol, which is the bulk solvent. We explored this selectivity and conclude that it results from various substrate-surface interactions, which are not attainable by methanol. The primary alcohol can outcompete the methanol for binding on the catalyst surface through various interactions between the side chain of the alcohol solvent and the surface of the catalyst: (listed in order of strength) lone pair-surface (heterocyclic primary alcohols)> [pi]-surface (aryl primary alcohols)> van der Waals-surface (alkyl primary alcohols). These interactions were previously underappreciated in condensed phase heterogeneously catalyzed aerobic oxidations. Bi and Te serve as synergistic promoters that enhance both the rate and yield of the reactions relative to reactions employing Pd alone or Pd in combination with Bi or with Te as the sole promoter. We report X-ray absorption spectroscopic studies of the heterogenous catalyst. These methods show that the promoters undergo oxidation in preference to Pd, maintaining the Pd surface in the active metallic state and preventing inhibition by surface Pd-oxide formation. The data also suggest formation of a Pd-Te alloy phase that modifies the electronic properties of the Pd catalyst. Collectively, these results provide valuable insights into the synergistic benefits of multiple promoters in heterogeneous catalytic oxidation reactions.

Author : Francesca Cardona
Publisher : Royal Society of Chemistry
Page : 304 pages
File Size : 19,89 MB
Release : 2015
Category : Science
ISBN : 1849738238

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This book deals with the search for environmentally benign procedures for the oxidation of alcohols and gives an overview of their transition-metal-catalyzed aerobic oxidation.

Author : Shannon S. Stahl
Publisher : John Wiley & Sons
Page : 454 pages
File Size : 48,46 MB
Release : 2016-10-10
Category : Technology & Engineering
ISBN : 3527337814

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The first book to place recent academic developments within the context of real life industrial applications, this is a timely overview of the field of aerobic oxidation reactions in the liquid phase that also illuminates the key challenges that lie ahead. As such, it covers both homogeneous as well as heterogeneous chemocatalysis and biocatalysis, along with examples taken from various industries: bulk chemicals and monomers, specialty chemicals, flavors and fragrances, vitamins, and pharmaceuticals. One chapter is devoted to reactor concepts and engineering aspects of these methods, while another deals with the relevance of aerobic oxidation catalysis for the conversion of renewable feedstock. With chapters written by a team of academic and industrial researchers, this is a valuable reference for synthetic and catalytic chemists at universities as well as those working in the pharmaceutical and fine chemical industries seeking a better understanding of these reactions and how to design large scale processes based on this technology.

Author : Dian Wang
Publisher :
Page : 194 pages
File Size : 39,95 MB
Release : 2017
Category :
ISBN :

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The selective oxidation of C-H bonds in (hetero)aromatics provides an efficient access to functionalized aromatic molecules of industrial interest. Aerobic oxygen is an ideal terminal oxidants for this transformation because it is readily available and often produces water as the sole byproduct. Homogeneous palladium catalysts are eminently compatible with aerobic turnovers and have seen success in numerous aerobic oxidation processes (e. g., alkene oxidation, alcohol oxidation). In contrast, palladium-catalyzed aerobic oxidative C-H functionalization has been rather underdeveloped. Challenges include slow catalytic turnover, catalyst decomposition and lack of selectivity control (e.g., site selectivity, homo- vs. cross-coupling selectivity). This thesis presents three research projects with different approaches to tackle the unsolved problems in the reaction class of palladium-catalyzed aerobic C-H oxidation of (hetero)aromatics. The reaction mechanism of C-H/C-H coupling of [o]-xylene was characterized, which disclosed a novel, bimetallic pathway. Built on this work, the effect of copper cocatalyst in this reaction was investigated, which revealed a non-traditional role of copper salt in oxidative palladium catalysis and led to the discovery of an improved catalyst system. Last, a synthetic methodology for aerobic indole C-H arylation with ligand-controlled site selectivity was developed, which provided efficient access to pharmaceutically-relevant aryl indoles and led to preliminary mechanistic insights into regiocontrol.

Author : Roger Sheldon
Publisher : Elsevier
Page : 447 pages
File Size : 22,84 MB
Release : 2012-12-02
Category : Science
ISBN : 0323150047

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Metal-Catalyzed Oxidations of Organic Compounds: Mechanistic Principles and Synthetic focuses on the oxidative transformations of functional groups. This book explores oxidation as being extensively used in the laboratory synthesis of fine organic chemicals and in the manufacture of large-volume petrochemicals. Organized into two parts encompassing 13 chapters, this book starts with an overview of the mechanistic principles of oxidation–reduction in biochemical, organic, and inorganic systems. This text then proceeds with a discussion of the use of molecular oxygen, hydrogen peroxide, and alkyl hydroperoxides as primary oxidants. Other chapters explore stoichiometric oxidations with metal oxidants, which include permanganate and chromic acid. This book discusses as well the synthetic applications of catalytic oxidations as well as the technology of petrochemical oxidation. The final chapter deals with the autoxidations of sulfur, phosphorus, and nitrogen compounds. This book is intended for chemists involved in organic synthesis, catalysis, and organometallic chemistry, both in academic institutions and in industrial laboratories.

Author : Shannon S. Stahl
Publisher : John Wiley & Sons
Page : 456 pages
File Size : 25,7 MB
Release : 2016-07-13
Category : Technology & Engineering
ISBN : 3527690158

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The first book to place recent academic developments within the context of real life industrial applications, this is a timely overview of the field of aerobic oxidation reactions in the liquid phase that also illuminates the key challenges that lie ahead. As such, it covers both homogeneous as well as heterogeneous chemocatalysis and biocatalysis, along with examples taken from various industries: bulk chemicals and monomers, specialty chemicals, flavors and fragrances, vitamins, and pharmaceuticals. One chapter is devoted to reactor concepts and engineering aspects of these methods, while another deals with the relevance of aerobic oxidation catalysis for the conversion of renewable feedstock. With chapters written by a team of academic and industrial researchers, this is a valuable reference for synthetic and catalytic chemists at universities as well as those working in the pharmaceutical and fine chemical industries seeking a better understanding of these reactions and how to design large scale processes based on this technology.

Author : Jan-Erling Bäckvall
Publisher : John Wiley & Sons
Page : 350 pages
File Size : 16,20 MB
Release : 2006-03-06
Category : Science
ISBN : 3527604642

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At the very latest, with the award of the 2001 Nobel Prize for work on asymmetric oxidation, there has been a need for a comprehensive book on such methods. Edited by J.-E. Backvall, one of the world's leaders in the field, this book fills that gap by covering the topic, from classical to green chemistry methods. He has put together a plethora of well-established authors from all over the world who cover every important aspect in high-quality contributions -- whether aerobic oxidation or transition metal-catalyzed epoxidation of alkenes. By providing an overview of this huge topic, this book represents an unparalleled aid for any chemist working in the field. Chapters include: Recent Developments in the Osmium-Catalyzed Dihydroxylation of Olefins Transition Metal-Catalyzed Epoxidation of Alkenes Organocatalytic Oxidation - Ketone-Catalyzed Asymmetric Epoxidation of Olefins Modern Oxidation of Alcohols using environmentally Benign Oxidants Aerobic Oxidations and Related Reactions Catalyzed by N-Hydroxyphthalimide Ruthenium-Catalyzed Oxidation of Alkenes, Alcohols, Amines, Amides, b-Lactams, Phenols, and Hydrocarbons Selective Oxidations of Sulfides and Amines Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates Oxidation of Carbonyl Compounds Mn-catalysed Oxidation with Hydrogen Peroxide