Reviews M. A. R. Meier et al. DOI: 10.1002/anie.201002767 Renewable Raw Materials Oils and Fats as Renewable Raw Materials in Chemistry Ursula Biermann, Uwe Bornscheuer, Michael A. R. Meier,* Jrgen O. Metzger, and Hans J. Schfer Keywords: Dedicated to Professor Marcel Lie Ken Jie on enzyme catalysis · fatty acids · the occasion of his 70th birthday homogeneous catalysis · polymers · renewable resources Angewandte Chemie 3854 www.angewandte.org 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2011, 50, 3854 – 3871 Renewable Resources Oils and fats of vegetable and animal origin have been the most From the Contents important renewable feedstock of the chemical industry in the past and in the present. A tremendous geographical and feedstock shift of 1. Introduction 3855 oleochemical production has taken place from North America and 2. Commodity Plant Oils and Fatty Europe to southeast Asia and from tallow to palm oil. It will be Acid Production 3857 important to introduce and to cultivate more and new oil plants containing fatty acids with interesting and desired properties for 3. Reactions of Unsaturated Fatty chemical utilization while simultaneously increasing the agricultural Compounds 3858 biodiversity. The problem of the industrial utilization of food plant oils 4. Enzymatic and Microbial has become more urgent with the development of the global biodiesel Transformations 3864 production. The remarkable advances made during the last decade in organic synthesis, catalysis, and biotechnology using plant oils and the 5. Summary and Outlook 3867 basic oleochemicals derived from them will be reported, including, for example, w-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. 1. Introduction development, since during the second half of the last century glycerol was petrochemically produced based on propene via The UN World Summit on Sustainable Development, epichlorohydrin. held in Johannesburg in 2002, called for the promotion of a Most of the native oils contain unsaturated fatty acids, sustainable use of biomass.[1] It was recently shown that such as oleic acid (1a), which is a cis-configured alkene and biomass can be produced in a volume sufficient for industrial thus allows, in principle, the application of the well-known utilization without compromising the food supply for the reactions of petrochemical alkenes. Remarkably, only very increasing global population.[2] Chemists have much to few reactions across the double bond of unsaturated fatty contribute to meet this challenge.[3,4] Oils and fats of compounds are currently applied in the chemical industry vegetable and animal origin are historically and currently (i.e., hydrogenation, ozone cleavage, and epoxidation). More- the most important renewable feedstock of the chemical over, there are no industrial processes utilizing selective CÀH industry. Classical and well-established oleochemical trans- functionalization of the alkyl chain of saturated and unsatu- formations occur preferentially at the ester functionality of rated long-chain fatty acids. Interesting exceptions are the the native triglycerides,[5] such as hydrolysis to free fatty acids production of C2-branched Guerbet alcohols from fatty and glycerol[6] and transesterification to fatty acid methyl alcohols[7] and the microbial w-oxidation of methyl oleate esters. Fatty acids are transformed by reactions at the carboxy 1bto cis-octadec-9-endioic acid dimethyl ester.[21] The latter is group to soaps, esters, amides, or amines. Hydrogenation of an example of the amazing opportunities offered by enzy- both fatty acids and their methyl esters gives fatty alcohols, matic and microbial reactions. which are used for the production of surfactants.[7] Compet- Fatty acids of plant seed oils show a remarkable variety.[22- itive petrochemical processes to produce fatty alcohols, such 24] In contrast, the fatty acids of bulk oils currently used in as the Ziegler Alfol process and hydroformylation of alkenes, exist, but the share of fatty alcohols from renewable resources [*] Prof. Dr. M. A. R. Meier is steadily increasing, from about 50% in 2000 to just under Karlsruhe Institute of Technology (KIT) [7,8] 65% in 2010. Institut fr Organische Chemie The basic oleochemicals (Scheme 1) are fatty acids (ca. Fritz-Haber-Weg 6, Gebude 30.42, 76131 Karlsruhe (Germany) 52%), the respective methyl esters (ca. 11%), amines (ca. E-mail: [email protected] 9%), and alcohols (ca. 25%).[9] These are used for the Dr. U. Biermann, Prof. Dr. J. O. Metzger production of important product groups,[6] that is, surfac- Universitt-Oldenburg tants,[10,11] lubricants,[12,13] and coatings.[14] The production Institut fr Reine und Angewandte Chemie Carl-von-Ossietzky-Straße 9–11, 26129 Oldenburg (Germany) volume of fatty acid methyl esters strongly increased during the last ten years because of their large-scale utilization as Prof. Dr. U. Bornscheuer [15–17] Ernst-Moritz-Arndt-Universitt Greifswald biodiesel, giving as side product about 10 wt% of Biotechnologie und Enzymkatalyse, Institut fr Biochemie glycerol which has to be utilized. This fact stimulated research Felix-Hausdorff-Straße 4 17487 Greifswald (Germany) on glycerol as a platform chemical for the production of bulk Prof. Dr. H. J. Schfer chemicals, that is, 1,2- and 1,3-propanediol, acrylic acid, or Universitt Mnster, Institut fr Organische Chemie epichlorohydrin.[18–20] The latter is an especially interesting Corrensstrasse 40, 48149 Mnster (Germany) Angew. Chem. Int. Ed. 2011, 50, 3854 – 3871 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 3855 Reviews M. A. R. Meier et al. oleochemistry are rather uniform. Saturated fatty acids with interesting substrate for organic synthesis, has not yet been an even number of carbon atoms (C8–C18) and unsaturated exploited appropriately (for some examples, see Sections 3.2 C18 fatty acids, such as 1a and linoleic acid (2a) as well as and 3.3). The latter applies generally to the utilization of the relatively small amounts of linolenic acid (3a), erucic acid synthetic potential of nature. (4a), and ricinoleic acid (5a) are industrially utilized. The Thus, it will be important to introduce and to cultivate most important oleochemical reactions performed with 5a more and new oil plants that provide fatty acids with new and are the thermal cleavage to 10-undecenoic acid 13a[25] and interesting properties for chemical utilization, such as petro- basic cleavage to sebacic acid (decanedioc acid).[26] Interest- selinic acid (6a) from the seed oil of Coriandrum sativum, ingly, the enantiomeric purity of 5a, which makes it an (5Z)-eicosenoic acid (7a) from meadowfoam (Limnanthes alba) seed oil,[27] calendic acid (8a) from Calendula officina- [28] Ursula Biermann studied food chemistry in lis, and a-eleostearic acid (9a) and punicic acid (10a) from [22] [29] Hannover and Munich. She received her tung (chinese wood) oil and pomegranate, respectively. doctorate at the Technische Universitt Santalbic acid (11a) is the main fatty acid of the seed oil of the Mnchen in 1979 under W. Grosch. Since sandalwood tree,[30] and it, together with vernolic acid (12a) 1987 she has been a research fellow under from Vernonia galamensis,[31] offers interesting synthetic J. O. Metzger at the Institute of Pure and applications. The cultivation of the respective plants for the Applied Chemistry of the Universitt Olden- burg, where she works on the synthesis of production of these oils would increase the agricultural novel fatty compounds using natural oils biodiversity, an important aspect of a sustainable utilization and fats as chemical raw materials. The of renewable feedstocks. Moreover, classic breeding as well as main focus of her studies lies in Lewis acid genetic engineering will be necessary to improve the oil yield induced, radical, and thermal addition reac- and the fatty acid composition for chemical utilization.[32–35] tions to the CÀC double bond of unsatu- In the 1980s, basic and applied research was intensified to rated fatty compounds. tackle these challenges. The results obtained until the end of the century were reviewed in 2000.[36] It was stated: “With the Uwe T. Bornscheuer (born 1964) studied breeding of new oil plants—including the use of gene chemistry and completed his doctorate in technology—numerous fatty compounds of adequate purity 1993 at the University of Hannover. He are now available which makes them attractive for synthesis. then was a postdoc at the University of Nagoya (Japan). In 1998, he completed his The use of modern synthetic methods together with enzy- habilitation at the University of Stuttgart at matic and microbial methods has led to an extraordinary the Institute of Technical Biochemistry. He expansion in the potential for the synthesis of novel fatty has been professor at the Institute of Bio- compounds, which are selectively modified in the alkyl chain. chemistry at the University of Greifswald … However, numerous synthetic problems remain unsolved since 1999. Bornscheuer edited and wrote and solutions must be found in the coming years.“[36a] several books, is Editor-in-Chief of Eur. J. Lipid Sci. Technol., and is co-chairman of the Editorial Board of ChemCatChem. In Jrgen O. Metzger studied chemistry at the 2008, he received the BioCat2008 Award for his innovative work on universities of Tbingen, Erlangen, Berlin, tailored biocatalysts for industrial