Jürgen O. Metzger

New Syntheses with Oils and Fats as Renewable Raw Materials for the Chemical Industry.

Oils and fats are the most important renewable raw materials for the chemical industry. Hitherto, industrial oleochemistry has concentrated predominantly on the carboxy functionality of fatty acids but, more recently, modern synthetic methods have been applied extensively to fatty compounds for the selective functionalization of the alkyl chain. Radical, electrophilic, nucleophilic, and pericyclic as well as transition metal catalyzed additions to the C-C double bond of, for example, oleic acid as the prototype of a readily accessible, unsaturated fatty acid have led to a large number of novel fatty compounds from which interesting properties are expected. Functionalization of C-H bonds in the alkyl chain is also feasible with remarkable selectivity. Effective and highly versatile catalysts for the metathesis of esters of unsaturated fatty acids have been developed, which lead to new and interesting omega-unsaturated fatty acids. The epoxidation of unsaturated fatty acids has been developed extensively. Enzymatic reactions allow syntheses with high selectivity and yield of mono- and diglycerides and esters of carbohydrates with a variety of surfactant properties. Regio- and enantioselective microbial hydrations and hydroxylations widen the spectrum of selective reactions. Of considerable significance is that, with the use of gene technology, natural oils and fats have been improved significantly and will be improved still further, insofar as they show a more uniform and often unusual fatty acid spectrum. Numerous fatty acids are now available in a purity which makes them attractive for synthesis and as raw materials for the chemical industry.

Oils and Fats as Renewable Raw Materials in Chemistry

Oils and fats of vegetable and animal origin have been the most important renewable feedstock of the chemical industry in the past and in the present. A tremendous geographical and feedstock shift of oleochemical production has taken place from North America and Europe to southeast Asia and from tallow to palm oil. It will be important to introduce and to cultivate more and new oil plants containing fatty acids with interesting and desired properties for chemical utilization while simultaneously increasing the agricultural biodiversity. The problem of the industrial utilization of food plant oils has become more urgent with the development of the global biodiesel production. The remarkable advances made during the last decade in organic synthesis, catalysis, and biotechnology using plant oils and the basic oleochemicals derived from them will be reported, including, for example, ω-functionalization of fatty acids containing internal double bonds, application of the olefin metathesis reaction, and de novo synthesis of fatty acids from abundantly available renewable carbon sources.

Lipids as renewable resources: current state of chemical and biotechnological conversion and diversification

Oils and fats are the most important renewable raw materials of the chemical industry. They make available fatty acids in such purity that they may be used for chemical conversions and for the synthesis of chemically pure compounds. Oleic acid (1) from “new sunflower,” linoleic acid (2) from soybean, linolenic acid (3) from linseed, erucic acid (4) from rape seed, and ricinoleic acid (5) from castor oil are most important for chemical transformations offering in addition to the carboxy group one or more C-C-double bonds. New plant oils containing fatty acids with new and interesting functionalities such as petroselinic acid (6) from Coriandrum sativum, calendic acid (7) from Calendula officinalis, α-eleostearic acid (8) from tung oil, santalbic acid (9) from Santalum album (Linn.), and vernolic acid (10) from Vernonia galamensis are becoming industrially available. The basic oleochemicals are free fatty acids, methyl esters, fatty alcohols, and fatty amines as well as glycerol as a by-product. Their interesting new industrial applications are the usage as environmentally friendly industrial fluids and lubricants, insulating fluid for electric utilities such as transformers and additive to asphalt. Modern methods of synthetic organic chemistry including enzymatic and microbial transformations were applied extensively to fatty compounds for the selective functionalization of the alkyl chain. Syntheses of long-chain diacids, ω-hydroxy fatty acids, and ω-unsaturated fatty acids as base chemicals derived from vegetable oils were developed. Interesting applications were opened by the epoxidation of C-C-double bonds giving the possibility of photochemically initiated cationic curing and access to polyetherpolyols. Enantiomerically pure fatty acids as part of the chiral pool of nature can be used for the synthesis of nonracemic building blocks.

10 Years after Rio-Concepts on the Contribution of Chemistry to a Sustainable Development

development.In this review we investigate innovations in chemistry exemplarily for such a development with regard to their ecological, economical, and social dimensions from an integrated and interdisciplinary perspective. Since base chemicals are produced in large quantities and important product lines are synthesized from them, their resource-saving production is especially important for a sustainable development. This concept has been shown, amongst others, by the example of the syntheses of propylene oxide and adipic acid. In the long run, renewable resources that are catalytically processed could replace fossil raw materials. Separation methods existing today must be improved considerably to lower material and energy consumption. Chemistry might become the pioneer of an innovative energy technique.The design of chemical products should make possible a sustainable processing and recycling and should prevent their bio-accumulation. Methods and criteria to assess their contribution to a sustainable development are necessary. The time taken to introduce the new more sustainable processes and products has to be diminished by linking their development with operational innovation management and with efficient environmental-political control procedures.

Sustainable global energy supply based on lignocellulosic biomass from afforestation of degraded areas

An important aspect of present global energy scenarios is the assumption that the amount of biomass that can be grown on the available area is so limited that a scenario based on biomass as the major source of energy should be unrealistic. We have been investigating the question whether a Biomass Scenario may be realistic. We found that the global energy demand projected by the International Energy Agency in the Reference Scenario for the year 2030 could be provided sustainably and economically primarily from lignocellulosic biomass grown on areas which have been degraded by human activities in historical times. Moreover, other renewable energies will contribute to the energy mix. There would be no competition with increasing food demand for existing arable land. Afforestation of degraded areas and investment for energy and fuel usage of the biomass are not more expensive than investment in energy infrastructure necessary up to 2030 assumed in the fossil energy based Reference Scenario, probably much cheaper considering the additional advantages such as stopping the increase of and even slowly reducing the CO2 content of the atmosphere, soil, and water conservation and desertification control. Most importantly, investment for a Biomass Scenario would be actually sustainable, in contrast to investment in energy-supply infrastructure of the Reference Scenario. Methods of afforestation of degraded areas, cultivation, and energetic usage of lignocellulosic biomass are available but have to be further improved. Afforestation can be started immediately, has an impact in some few years, and may be realized in some decades.

Neue Synthesen mit Ölen und Fetten als nachwachsende Rohstoffe für die chemische Industrie

Ole und Fette sind die wichtigsten nachwachsenden Rohstoffe der chemischen Industrie. Die industrielle Oleochemie konzentriert sich bisher uberwiegend auf die Carboxyfunktion der Fettsauren, doch wurden in letzter Zeit auch moderne Synthesemethoden zur selektiven Funktionalisierung in der Alkylkette auf Fettstoffe angewandt. Additionen an die C-C-Doppelbindung z. B. von Olsaure als Prototyp einer gut zuganglichen ungesattigten Fettsaure fuhrten zu einer Vielzahl neuartiger Fettstoffe mit interessanten Eigenschaften. Auch Funktionalisierungen von C-H-Bindungen in der Alkylkette sind bemerkenswert selektiv moglich. Es wurden effektive Katalysatoren fur die Metathese ungesattigter Fettsaureester entwickelt, die zu vielfaltig einsetzbaren ω-ungesattigten Fettsauren fuhrt. Die Epoxidierung ungesattigter Fettsauren wurde wesentlich weiterentwickelt. Enzymatische Reaktionen erlauben mit hoher Selektivitat und Ausbeute die Synthese von Mono- und Diglyceriden und von Kohlenhydratestern mit interessanten oberflachenaktiven Eigenschaften. Regio- und enantioselektive mikrobielle Hydratisierungen und Hydroxylierungen erweitern das Spektrum der selektiven Reaktionen. Die nativen Ole und Fette wurden durch Pflanzenzuchtung (auch gentechnisch) betrachtlich verbessert, und zahlreiche Fettsauren stehen heute in genugender Reinheit fur die Synthese und als Rohstoff fur die chemische Industrie zur Verfugung.

10 Jahre nach „Rio“ – Konzepte zum Beitrag der Chemie zu einer nachhaltigen Entwicklung

In der Erklarung der Konferenz fur Umwelt und Entwicklung der Vereinten Nationen in Rio de Janeiro 1992 und in der Agenda 21, dem vor nun zehn Jahren von mehr als 170 Staaten verabschiedeten Arbeitsprogramm fur das 21. Jahrhundert, werden die dringlichsten Fragen von heute angesprochen, wahrend gleichzeitig versucht wird, die Welt auf die Herausforderungen dieses Jahrhunderts vorzubereiten. Im Zentrum stehen die Erhaltung und Bewirtschaftung der Ressourcen fur die Entwicklung. Einen wesentlichen Beitrag dazu mussen die Wissenschaften leisten, wobei es der Zusammenfuhrung natur-, wirtschafts- und sozialwissenschaftlicher Erkenntnisse bedarf. Die Verbande der chemischen Industrien Europas, Japans und der USA haben sich in ihren Zukunftsprogrammen explizit zu ihrer Verpflichtung zu einer nachhaltigen Entwicklung bekannt. Wir untersuchen in diesem Aufsatz beispielhaft Innovationen der Chemie fur eine solche Entwicklung in ihrer okologischen, okonomischen und sozialen Dimension unter einer integrierten und interdisziplinaren Perspektive. Die ressourcenschonende Produktion von Basischemikalien ist aufgrund der grosen produzierten Mengen und der darauf aufbauenden Produktlinien fur eine nachhaltige Entwicklung von besonderer Bedeutung. Dies wird unter anderem am Beispiel von Propylenoxid und Adipinsaure gezeigt. Langfristig konnten die nachwachsenden Rohstoffe, die katalytisch weiterverarbeitet werden, fossile Rohstoffe ersetzen. Die heute existierenden Trennmethoden mussen wesentlich verbessert werden, damit der Material- und Energieverbrauch gesenkt wird. Die Chemie konnte Wegbereiter einer innovativen Energietechnik werden. Die chemischen Produkte mussen so gestaltet werden, dass sie nachhaltig weiterverarbeitet, recycelt und nicht bioakkumuliert werden konnen. Methoden und Kriterien zur Bewertung ihres Beitrags zu einer nachhaltigen Entwicklung sind notwendig. Die Zeit zur Einfuhrung der neuen Prozesse und Produkte muss durch die enge Verbindung ihrer Entwicklung mit dem betrieblichen Innovationsmanagement und effizienten umweltpolitischen Steuerungsverfahren verringert werden.

Thermal degradation of chitin and cellulose

Abstract Dry chitin was thermally degraded under nitrogen. The main volatile degradation product was acetamide. Chitin and cellulose were depolymerized by thermal degradation in tetraethyleneglycol dimethylether as a high boiling and inert solvent to give water-soluble oligomers with a terminal anhydrosugar unit. In supercritical acetone, cellulose could be degraded to the extent of 98% and chitin to the extent of 85%. Monomeric anhydrosugars were formed with good yields and could be identified and isolated from the degradation syrups.

ESIMS Studies and Calculations on Alkali‐Metal Adduct Ions of Ruthenium Olefin Metathesis Catalysts and Their Catalytic Activity in Metathesis Reactions

Electrospray ionization mass spectrometry (ESIMS) and subsequent tandem mass spectrometry (MS/MS) analyses were used to study some important metathesis reactions with the first-generation ruthenium catalyst 1, focusing on the ruthenium complex intermediates in the catalytic cycle. In situ cationization with alkali cations (Li(+), Na(+), K(+), and Cs(+)) using a microreactor coupled directly to the ESI ion source allowed mass spectrometric detection and characterization of the ruthenium species present in solution and particularly the catalytically active monophosphine-ruthenium intermediates present in equilibrium with the respective bisphosphine-ruthenium species in solution. Moreover, the intrinsic catalytic activity of the cationized monophosphine-ruthenium complex 1 aK(+) was directly demonstrated by gas-phase reactions with 1-butene or ethene to give the propylidene Ru species 3 aK(+) and the methylidene Ru species 4 aK(+), respectively. Ring-closing metathesis (RCM) reactions of 1,6-heptadiene (5), 1,7-octadiene (6) and 1,8-nonadiene (7) were studied in the presence of KCl and the ruthenium alkylidene intermediates 8, 9, and 10, respectively, were detected as cationized monophosphine and bisphosphine ruthenium complexes. Acyclic diene metathesis (ADMET) polymerization of 1,9-decadiene (14) and ring-opening metathesis polymerization (ROMP) of cyclooctene (18) were studied analogously, and the expected ruthenium alkylidene intermediates were directly intercepted from reaction solution and characterized unambiguously by their isotopic patterns and ESIMS/MS. ADMET polymerization was not observed for 1,5-hexadiene (22), but the formation of the intramolecularly stabilized monophosphine ruthenium complex 23 a was seen. The ratio of the signal intensities of the respective with potassium cationized monophosphine and bisphosphine alkylidene Ru species varied from [I(4a)]/[I(4)]=0.02 to [I(23a)]/[I(23)]=10.2 and proved to be a sensitive and quantitative probe for intramolecular pi-complex formation of the monophosphine-ruthenium species and of double bonds in the alkylidene chain. MS/MS spectra revealed the intrinsic metathesis catalytic activity of the potassium adduct ions of the ruthenium alkylidene intermediates 8 a, 9 a, 10 a, 15 a, and 19 a, but not 23 a by elimination of the respective cycloalkene in the second step of RCM. Computations were performed to provide information about the structures of the alkali metal adduct ions of catalyst 1 and the influence of the alkali metal ions on the energy profile in the catalytic cycle of the metathesis reaction.

New type of matrix for matrix-assisted laser desorption mass spectrometry of polysaccharides and proteins

Abstract3-Aminoquinoline is introduced as matrix for matrix-assisted laser desorption mass spectrometry of polysaccharides and proteins. The first MALD mass spectrum of the polysaccharide inulin is reported. 3-Aminoquinoline seems to be more effective than the commonly used acidic matrix 2,5-dihydroxybenzoic acid, assisting in the desorption and ionisation of inulin. A higher sensitivity, sharper peaks and a lower background were observed. 3-Aminoquinoline is also quite effective when measuring the protein myoglobin.