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Aqueous hydroaminomethylation (HAM) is an atom economical route for the efficient production of amines in one reaction step, starting from basic chemicals like alkenes. Herein we present the first successful establishment of a continuous process for HAM in an aqueous multiphase system. The green mass transfer agents randomly methylated-β-cyclodextrins (CD) enabled the catalytic system consisting of rhodium/sulfoXantphos to achieve high yields of up to 70% with selectivities of up to 80% in several continuous experiments with a total run time of more than 220 h. The key here is that water and products have large polarity differences, but the reaction still proceeds effectively due to the addition of cyclodextrin, which made the application of solvents obsolete. The main achievements in this way were the investigation of the influence of the randomly methylated-β-cyclodextrin concentration on the reaction rate and the selectivity in batch studies and finding promising operating points in the first continuous experiments. In a final experiment, the separation temperature was investigated. It was shown that the catalyst loss in the product phase is enormously small at 0.003% h−1 of the initial mass (0.24% in total), which is the lowest ever reported value for the HAM on this scale. Within a run time of 78 hours, 2.87 kg of tertiary amine were produced using only 0.2 g (>14 000 : 1) of transition metal, while the loss of rhodium per kg of product produced was mostly around 0.15 mg kg−1, suggesting possible economical applicability. 25;9

For the first time, palladium-catalyzed carbonylative telomerization enables the one-step synthesis of mixed carboxylic anhydrides directly from butadiene. These anhydrides are versatile intermediates and were used to form amides.

The bidentate phosphine ligand 1,2-bis(di-tert-butylphosphinomethyl)benzene (1,2-DTBPMB) has been reported over the years as being one of, if not the, best ligands for achieving the alkoxycarbonylation of various unsaturated compounds. Bonded to palladium, the ligand provides the basis for the first step in the commercial (Alpha) production of methyl methacrylate as well as very high selectivity to linear esters and acids from terminal or internal double bonds. The present review is an overview covering the literature dealing with the 1,2-DTBPMB ligand: from its first reference, its catalysis, including the alkoxycarbonylation reaction and its mechanism, its isomerization abilities including the highly selective isomerizing methoxycarbonylation, other reactions such as cross-coupling, recycling approaches, and the development of improved, modified ligands, in which some tert-butyl ligands are replaced by 2-pyridyl moieties and which show exceptional rates for carbonylation reactions at low temperatures.

Solvents have an enormous impact on yield and turnover of chemical reactions in complex media. There is, however, a lack of consistent model-based tools to a priori identify the appropriate solvent...

Feasibility of oxidative cleavage of methyl oleate in a homogeneous reaction, facilitating the subsequent recovery of the catalyst from a single phase, is a challenge. Using the high molecular catalyst phosphotungstic acid (2880 Da) as an affordable catalyst offers potential for membrane separation. To gain insight into side-reactions, the intermediate methyl 9,10-dihydroxystearate was first applied as a model substrate. Thus, the stability of the intermediate methyl 9,10-epoxystearate and the vicinal diol was significantly improved under reaction conditions. Oxidative cleavage of the vicinal diol as a stable intermediate is very promising reaching an overall selectivity of 90% and a selectivity towards the cleavage carboxylic acids of 80%, considering dilution and acidity as the most important parameters. Retention of the catalyst via organic solvent nanofiltration was investigated and we retained 94% of the catalyst in the monophasic system as the first step towards a process concept for a product purification or catalyst recycling strategy., Catalysis science & technology;12(11)

A reactive ionic liquid was successfully applied in the homogeneous ruthenium-catalyzed alcohol amination for the first time. Through detailed investigation of the phase behavior and the applicatio...

We present the development of catalytic auto-tandem reactions into continuous flow processes on the example of homogeneously catalyzed hydroaminomethylation (HAM, consisting of hydroformylation and...

For the first time, the reactive ionic liquid N,N-dimethyl ammonium N,N-dimethyl carbamate (dimcarb) was used as a polar solvent in the palladium-catalyzed telomerisation of the renewable monoterpene β-myrcene. By doing so, it was possible to avoid any volatile organic solvents. Moreover, the special decomposition behaviour of the reactive ionic liquid dimcarb could be exploited to the extent that dimethyl amine was used as a reagent in the reaction. Accordingly, non-symmetrical C20-chain dimethyl amines were produced from β-myrcene and dimethylamine liberated by dimcarb, achieving selectivities higher than 80%. Detailed investigations revealed the thermomorphic behaviour of the reaction mixture consisting only of dimcarb, β-myrcene and the catalytic system. The advantageous temperature-dependent phase behaviour resulted in one liquid phase occurring at the reaction temperature and two liquid phases upon cooling. Consequently, a virtually pure organic product phase could be separated from the polar catalyst-containing dimcarb phase. Immobilization of the catalyst in the polar reactive ionic liquid phase was ensured by the use of sulfonated triphenylphosphine derivatives. Subsequently, the separated catalyst-containing dimcarb phase was successfully reused in 14 consecutive recycling runs with only minimal leaching of both the catalyst and dimcarb, reaching a total turnover number of 12 000.

For the first time, the successful application of the homogeneously catalyzed reductive amination in a thermomorphic multiphase system (TMS) and the first reported scale-up of this reaction into a ...

Catalytic oxidation of sustainable raw materials like unsaturated fats and oils, or fatty acids and their esters, lead to biobased, high-value products. Starting from technical grade methyl oleate, hydrogen peroxide as a green oxidant produces only water as by-product. A commercially available, cheap water-soluble tungsten catalyst is combined with Aliquat® 336 as a phase-transfer agent in solvent-free reaction conditions. In this study, we first report the transfer of this well-known batch system into continuous mode. The space–time yield is improved from 0.08 kg/L.h in batch to 1.29 kg/L.h in flow mode. The improved mass transfer and reduced back mixing of the biphasic liquid–liquid slug flow allows for selectivity control depending on physical parameters of slug flow namely volumetric phase ratio, volumetric flow rate, and slug length. Even though the product, methyl 9,10-epoxystearate is obtained at a maximum selectivity of only 58% in flow mode, higher space time yield combined with possible reactant recycling in flow mode offers a promising avenue of research. This work analyses the use of slug flow parameters as tools for controlling selectivity towards oxidation products of methyl oleate., Journal of flow chemistry;Bd 11. 2021, H. 3, S. 407-427

Over the past 20 years, thermomorphic multiphase systems (TMS) have been used as a versatile and elegant strategy for the recovery and recycling of homogeneous transition-metal catalysts, in both batch-scale experiments and continuously operated processes. TMS ensure a homogeneous reaction in a monophasic reaction mixture at reaction temperature and the recovery of the homogeneous transition-metal catalyst through liquid-liquid separation at a lower separation temperature. This is achieved by using at least two solvents, which have a highly temperature-sensitive miscibility gap. The suitability of commercially available solvents makes this approach highly interesting from an industrial point of view. For the first time, herein, all studies in the area of TMS are reviewed, with the aim of providing a concise and integral representation of this approach for homogeneous catalyst recovery. In addition to the discussion of examples from the literature, the thermodynamic fundamentals of the temperature-dependent miscibility of solvents are also presented. This review also gives key indicators to compare different TMS approaches, for instance. In this way, new solvent combinations and in-depth research, as well as improvements to existing approaches, can be addressed and promoted.

An alternative strategy for the Rh-catalysed hydroformylation of technical-grade methyl oleate in aqueous-media has been developed. This is achieved with the water-soluble Rh/NaTPPTS catalyst dissolved in a green polar phase consisting only of the safe and benign solvents water and 2-propanol. This approach allows to completely avoid the use of additional auxiliaries like surfactants, cyclodextrins, or other phase-transfer agents. Along with efficient immobilization and recycling of the catalyst, excellent chemo- (>96%) and regioselectivity (>98%) to the desired branched aldehyde products is achieved. Investigations on the composition- and temperature-dependent phase-behaviour of the multicomponent liquid system water/2-propanol/methyl oleate are carried out in order to optimise all reaction parameters. Beneficially, a pure nonpolar aldehyde product phase is obtained after reaction, containing only low amounts of 2-propanol (

The bidentate phosphine ligand 1,2-bis(di

International audience; Hydroaminomethylation (HAM) is a highly efficient homogeneously catalyzed autotandem reaction converting alkenes into valuable amine products with water being the only coproduct. This work reports for the first time the scale-up of the highly regioselective HAM of 1-decene with diethylamine for a potential continuous process application in a green and sustainable aqueous biphasic medium. The catalytic system Rh/SulfoXantphos and randomly methylated β-cyclodextrin (RAME-β-CD) were herein dissolved in the plain aqueous phase. The addition of cyclodextrins as a green mass transfer agent remarkably increases the reaction rate as well as the selectivity toward linear amines, but they can also support solid content precipitation in this reaction system due to up-scaling effects. Therefore, parameters such as catalyst concentration, organic volume fraction, cyclodextrin concentration, and recyclability were investigated regarding the stability and activity of the system. Especially the organic volume fraction had a decisive influence on solid content precipitation. High regio- and chemoselectivities of 35 and 82%, respectively, at nearly full conversion were achieved toward the linear product amine. The catalytic system was further recycled in batch and scaled up into a 2100 mL autoclave without loss in activity and selectivity. Finally, a continuous process concept was proposed for an extensive investigation regarding long-term stability of the catalytic system.

Selective product crystallization proved to be a very attractive recycling strategy for homogeneous catalysts. This approach was demonstrated for the Pd-catalyzed isomerizing methoxycarbonylation o...

For the first time, randomly methylated β-cyclodextrin was applied as the mass transfer agent in a continuous process. Considering the example of the Rh-catalyzed hydroformylation of 1-decene, process development was shown, where cyclodextrin was used together with a catalyst system that was continuously recovered and recycled using an aqueous biphasic system. In initial experiments, water-soluble and commercially available Rh/TPPTS and Rh/sulfoxantphos catalyst systems were scaled up from 50 ml into 1000 ml high-pressure autoclave systems to demonstrate their scalability. Both these systems were compared, and they afforded excellent chemoselectivity (>99%) toward the desired linear aldehyde product. In particular, higher regioselectivity (up to 31) was achieved for the Rh/sulfoxantphos system. Investigations regarding the long-term stability of the mass transfer agent and both catalyst systems were carried out in a continuously operated miniplant process. It was shown that the process could be successfully operated under the steady state for over 200 h with chemoselectivity of >97% toward the desired aldehyde product. Simultaneously, extremely low Rh leaching (total: 0.59%) was observed over the entire period of 200 h.

Chapter Timetable You get to know the different classes of terpenes as well as their industrial extraction The important class of acyclic and cyclic monoterpenes The classes of higher terpenes, i.e. sesqui-, di-, tri- and tetraterpenes.

Chapter Timetable In this chapter, we will get to know the structure of the polysaccharide chitin, where it occurs in nature and how it can be used industrially. The transformation of chitin into chitosan is explained. Some applications of chitin and chitosan are discussed in more detail. Finally, we get to know some other polysaccharides derived from algae.

Chapter Timetable An introduction into the compound class of carbohydrates is given. You will learn about the most important monosaccharides, their production and processing. The main focus is on the future possibilities of glucose chemistry. We will discuss the extraction of sugar from sugar cane and sugar beets as well as the conversion of sucrose into numerous secondary products, e.g. by hydrolysis, oxidation or biotransformation.

Chapter Timetable The term aromatic substance will be defined, and we learn about the historical development of fragrances and flavors. We distinguish natural fragrances and aromas from synthetic ones and look at some important representatives of synthetic fragrances. The most important production methods for essential oils are explained.

Chapter Timetable We learn about natural rubber and its manufacture from latex. The special properties of natural rubber lead to many interesting applications, which we will discuss more in detail.

Chapter Timetable We will discuss the term “biorefineries” in more detail and place it in the context of renewable raw materials. Using examples, we will get to know the classification of the different biorefinery concepts.

Aldoxime synthesis directly starting from alkenes was successfully achieved through the combination of hydroformylation and subsequent condensation of the aldehyde intermediate with aqueous hydroxylamine in a one-pot process. The metal complex Rh(acac)(CO)(2) and the water-soluble ligand sulfoxantphos were used as the catalyst system, providing high regioselectivities in the initial hydroformylation. A mixture of water and 1-butanol was used as an environmentally benign solvent system, ensuring sufficient contact of the aqueous catalyst phase and the organic substrate phase. The reaction conditions were systematically optimised by Design of Experiments (DoE) using 1-octene as a model substrate. A yield of 85% of the desired linear, terminal aldoxime ((E/Z)-nonanal oxime) at 95% regioselectivity was achieved. Other terminal alkenes were also converted successfully under the optimised conditions to the corresponding linear aldoximes, including renewable substrates. Differences of the reaction rate have been investigated by recording the gas consumption, whereby turnover frequencies (TOFs) >2000 h(-1) were observed for 4-vinylcyclohexene and styrene, respectively. The high potential of aldoximes as platform intermediates was shown by their subsequent transformation into the corresponding linear nitriles using aldoxime dehydratases as biocatalysts. The overall reaction sequence thus allows for a straightforward synthesis of linear nitriles from alkenes with water being the only by-product, which formally represents an anti-Markovnikov hydrocyanation of readily available 1-alkenes.

Chapter Timetable We take a look at the history of the art of dyeing. You will learn about the historically most important natural dyestuffs, such as Tyrian purple, alizarin and indigo. Finally, other important natural dyes, such as carmine and carotene, will be presented.

Chapter Timetable We briefly discuss the chemistry of the saturated fatty acid alkyl chain. Much more versatile is the chemistry of the C=C double bond of unsaturated fatty acid compounds. Here you will get to know the possibilities of using C–O and C–C linkages to derive new functionalized or branched molecules. The selective hydrogenation of C=C double bonds is also discussed.

Chapter Timetable You will learn about the properties of glycerol and where it can be used. The main part of this chapter deals with the follow-up chemistry of glycerol, which has been intensively investigated in recent years.

Chapter Timetable You will learn the composition of wood and how to extract cellulose from wood. The paper production as the most important use of cellulose is explained. We discuss the derivatization of cellulose to fibers, esters and ether.

Chapter Timetable Here, you can find out which materials belong to the renewable raw materials. You will learn the most important renewable raw materials in terms of quantity (the primary ingredients), but also the structurally important secondary raw materials. The renewable raw materials are compared with the fossil raw materials coal, petroleum and natural gas. We are discussing whether the renewable raw materials will reduce fossil fuel consumption or can completely replace it. The advantages, but also the accompanying problems of the renewable raw materials, are explained.

Chapter Timetable A look at the history of natural pharmaceuticals shows us that many active ingredients have been used by mankind for thousands of years. We will take a closer look at some particularly important active ingredients as examples: acetylsalicylic acid, some alkaloids, antibiotics and steroids.

Chapter Timetable You will learn several methods for splitting triglycerides into the basic chemicals fatty acids (or fatty acid esters, respectively) and glycerol. We will discuss the chemistry of the carboxy group of fatty acids, which leads us to fatty alcohols and fatty amines, among others.

Chapter Timetable In preliminary, an overview is given of the significance of vitamins for mankind. The 13 vitamins are then briefly presented in detail.

Chapter Timetable In this chapter, we will take a closer look at the occurrence and significance of lignin for plants. The special chemical structure of lignin will be examined in more detail using some binding principles. We will look at the processes in which lignin is produced and how it can be obtained in a highly pure form. Finally, the most important applications of lignin will be discussed.

Chapter Timetable The chemical structure of starch as well as its composition is discussed. You will get to know the most important sources of starch and its industrial production. We discuss the material use of starch and its chemical transformation into interesting derivatives.

Chapter Timetable We will take a closer look at the structure and production of cyclodextrins. The special reactivity of cyclodextrins will be discussed. The most important applications and derivatizations are briefly presented.

Chapter Timetable The nomenclature of oleochemistry is explained and the most important fatty acids are discussed. You will learn which fats and oils are of technical importance and why. The twelve most important vegetable fats and oils are presented, each with a description of the plant, the oil, its extraction, its composition and its most important applications. The animal fats and oils are briefly introduced to you. At the end, you will get an insight into the production figures of fats and oils.

Chapter Timetable The term biopolymer is defined and explained in more detail using various examples. The different demands posed for biopolymers are examined in more detail and discussed using typical representatives.

Chapter Timetable In this chapter, you will find out about the amino acids, their structure, their physical characteristics, their occurrence, their synthesis and their use. A number of amino acids are linked to form peptides. You will also get to know proteins and enzymes.