|Died||26 August 1987 90) (aged|
|Alma mater||University of Marburg|
|Known for|| Wittig reaction |
|Awards|| Otto Hahn Prize for Chemistry and Physics (1967)|
Paul Karrer Gold Medal (1972)
Nobel Prize in Chemistry (1979)
|Institutions|| University of Marburg |
University of Freiburg
University of Tübingen
University of Heidelberg
|Doctoral advisor||Karl von Auwers|
|Doctoral students||Werner Tochtermann, Ulrich Schöllkopf|
Georg Wittig (16 June 1897 – 26 August 1987) was a German chemist who reported a method for synthesis of alkenes from aldehydes and ketones using compounds called phosphonium ylides in the Wittig reaction. He shared the Nobel Prize in Chemistry with Herbert C. Brown in 1979.
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, reaction rates, and other chemical properties. The word 'chemist' is also used to address Pharmacists in Commonwealth English.
In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond. The words alkene and olefin are often used interchangeably (see nomenclature section below). Acyclic alkenes, with only one double bond and no other functional groups, known as mono-enes, form a homologous series of hydrocarbons with the general formula CnH2n. Alkenes have two hydrogen atoms fewer than the corresponding alkane (with the same number of carbon atoms). The simplest alkene, ethylene (C2H4), with the International Union of Pure and Applied Chemistry (IUPAC) name ethene, is the organic compound produced on the largest scale industrially. Aromatic compounds are often drawn as cyclic alkenes, but their structure and properties are different and they are not considered to be alkenes.
An aldehyde is an organic compound containing a functional group with the structure −CHO, consisting of a carbonyl center with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain. The group—without R—is the aldehyde group, also known as the formyl group. Aldehydes are common in organic chemistry, and many fragrances are aldehydes.
Wittig was born in Berlin, Germany and shortly after his birth moved with his family to Kassel, where his father was professor at the applied arts high school. He attended school in Kassel and started studying chemistry at the University of Tübingen 1916. He was drafted and became a lieutenant in the cavalry of Hesse-Kassel (or Hesse-Cassel). After being an English prisoner of war from 1918 till 1919, Wittig found it hard to restart his chemistry studies owing to overcrowding at the universities. By a direct plea to Karl von Auwers, who was professor for organic chemistry at the University of Marburg at the time, he was able to resume university study and after 3 years was awarded the Ph.D. in organic chemistry.
Kassel is a city located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Regierungsbezirk Kassel and the district of the same name and had 200,507 inhabitants in December 2015. The former capital of the state of Hesse-Kassel has many palaces and parks, including the Bergpark Wilhelmshöhe, which is a UNESCO World Heritage Site. Kassel is also known for the documenta exhibitions of contemporary art. Kassel has a public university with 25,000 students (2018) and a multicultural population.
The University of Tübingen, officially the Eberhard Karls University of Tübingen, is a public research university located in the city of Tübingen, Baden-Württemberg, Germany.
Kassel is one of the three Regierungsbezirke of Hesse, Germany, located in the north of the state. It was created in 1866 when Prussia annexed the area to form the new province Hesse-Nassau. Altogether it consists of 138 municipalities.
Karl von Auwers was able to convince him to start an academic career, leading to his habilitation in 1926. He became a close friend of Karl Ziegler, who was also doing his habilitation with Auwers during that time. The successor of Karl von Auwers, Hans Meerwein, accepted Wittig as lecturer, partly because he was impressed by the new 400-page book on stereochemistry that Wittig had written. In 1931 Wittig married Waltraud Ernst, a colleague from the Auwers working group. The invitation of Karl Fries brought him as professor to the TU Braunschweig in 1932. The time in Braunschweig became more and more problematic as the Nazis tried to get rid of Karl Fries and Wittig showed solidarity with him. After the forced retirement of Fries, in 1937 Hermann Staudinger offered Wittig a position at the University of Freiburg, partly because he knew Wittig from his book on stereochemistry in which he supported Staudinger's highly criticized theory of macromolecules. The foundations of carbanion chemistry were laid during Wittig's time in Freiburg.
Karl Waldemar Ziegler was a German chemist who won the Nobel Prize in Chemistry in 1963, with Giulio Natta, for work on polymers. The Nobel Committee recognized his "excellent work on organometallic compounds [which]...led to new polymerization reactions and ... paved the way for new and highly useful industrial processes". He is also known for his work involving free-radicals, many-membered rings, and organometallic compounds, as well as the development of Ziegler–Natta catalyst. One of many awards Ziegler received was the Werner von Siemens Ring in 1960 jointly with Otto Bayer and Walter Reppe, for expanding the scientific knowledge of and the technical development of new synthetic materials.
Karl Friedrich von Auwers was a German chemist and the academic adviser of Karl Ziegler and Georg Wittig at the University of Marburg.
Hans Meerwein was a German chemist. Several reactions and reagents bear his name, most notably the Meerwein–Ponndorf–Verley reduction, the Wagner–Meerwein rearrangement, the Meerwein arylation reaction, and Meerwein's salt.
In 1944 he succeeded the head of the organic chemistry department Wilhelm Schlenk at the University of Tübingen. Most of his scientific work, including the development of the Wittig reaction, was performed during this time in Tübingen. The 1956 appointment of the nearly sixty-year-old Wittig as head of the organic chemistry department at the University of Heidelberg as successor of Karl Freudenberg was exceptional even at that time. The newly built department and the close connection to the BASF convinced Wittig to take this opportunity. He worked at the University of Heidelberg even after his retirement in 1967 and published papers until 1980. Most of his awards were presented during this time at Heidelberg, such as the honorary doctorate of the Sorbonne in 1956 and the Nobel Prize in Chemistry in 1979.
Wilhelm Johann Schlenk was a German chemist. He was born in Munich and also studied chemistry there. Schlenk succeeded Emil Fischer at the University of Berlin in 1919.
The Wittig reaction or Wittig olefination is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide to give an alkene and triphenylphosphine oxide.
Karl Johann Freudenberg was a German chemist who did early seminal work on the absolute configurations to carbohydrates, terpenes, and steroids, and on the structure of cellulose and other polysaccharides, and on the nature, structure, and biosynthesis of lignin. The Research Institute for the Chemistry of Wood and Polysaccharides at the University of Heidelberg was created for him in the mid to late 1930s, and he led this until 1969.
Wittig's contributions also include the preparation of phenyllithium and the discovery of the 1,2-Wittig rearrangement and the 2,3-Wittig rearrangement.
Phenyllithium or lithobenzene is an organometallic agent with the empirical formula C6H5Li. It is most commonly used as a metalating agent in organic syntheses and a substitute for Grignard reagents for introducing phenyl groups in organic syntheses. Crystalline phenyllithium is colorless; however, solutions of phenyllithium are various shades of brown or red depending on the solvent used and the impurities present in the solute.
A 1,2-Wittig rearrangement is a categorization of chemical reactions in organic chemistry, and consists of a 1,2-rearrangement of an ether with an alkyllithium compound. The reaction is named for Nobel Prize winning chemist Georg Wittig.
The [2,3]-Wittig rearrangement is the transformation of an allylic ether into a homoallylic alcohol via a concerted, pericyclic process. Because the reaction is concerted, it exhibits a high degree of stereocontrol, and can be employed early in a synthetic route to establish stereochemistry. The Wittig rearrangement requires strongly basic conditions, however, as a carbanion intermediate is essential. [1,2]-Wittig rearrangement is a competitive process.
Wittig was well known in the chemistry community for being a consummate experimenter and observer of chemical transformations, while caring very little for the theoretical and mechanistic underpinnings of the work he produced.
Georg also has his name on a literature work titled on a compound labelled Colopidalol.
Justus Freiherr von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and was considered the founder of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the greatest chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and trace minerals as essential plant nutrients, and his formulation of the law of the minimum, which described how plant growth relied on the scarcest nutrient resource, rather than the total amount of resources available. He also developed a manufacturing process for beef extracts, and with his consent a company, called Liebig Extract of Meat Company, was founded to exploit the concept; it later introduced the Oxo brand beef bouillon cube. He popularized an earlier invention for condensing vapors, which came to be known as the Liebig condenser.
In organic chemistry, the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene derivative. It is the prototypical example of a pericyclic reaction with a concerted mechanism. More specifically, it is classified as a thermally-allowed [4+2] cycloaddition with Woodward–Hoffmann symbol [π4s + π2s]. It was first described by Otto Diels and Kurt Alder in 1928. For the discovery of this reaction, they were awarded the Nobel Prize in Chemistry in 1950. Through the simultaneous construction of two new carbon–carbon bonds, the Diels–Alder reaction provides a reliable way to form six-membered rings with good control over the regio- and stereochemical outcomes. Consequently, it has served as a powerful and widely applied tool for the introduction of chemical complexity in the synthesis of natural products and new materials. The underlying concept has also been applied to π-systems involving heteroatoms, such as carbonyls and imines, which furnish the corresponding heterocycles; this variant is known as the hetero-Diels–Alder reaction. The reaction has also been generalized to other ring sizes, although none of these generalizations have matched the formation of six-membered rings in terms of scope or versatility. Because of the negative values of ΔH° and ΔS° for a typical Diels–Alder reaction, the microscopic reverse of a Diels–Alder reactions becomes favorable at high temperatures, although this is of synthetic importance for only a limited range of Diels-Alder adducts, generally with some special structural features; this reverse reaction is known as the retro-Diels–Alder reaction.
Kurt Alder was a German chemist and Nobel laureate.
Richard Johann Kuhn was an Austrian-German biochemist who was awarded the Nobel Prize in Chemistry in 1938 "for his work on carotenoids and vitamins".
Benzoin is an organic compound with the formula PhCH(OH)C(O)Ph. It is a hydroxy ketone attached to two phenyl groups. It appears as off-white crystals, with a light camphor-like odor. Benzoin is synthesized from benzaldehyde in the benzoin condensation. It is chiral and it exists as a pair of enantiomers: (R)-benzoin and (S)-benzoin.
Rudolf Criegee was a German organic chemist.
Carl Dietrich Harries was a German chemist born in Luckenwalde, Brandenburg, Prussia. He received his doctorate in 1892. In 1900, he married Hertha von Siemens, daughter of the electrical genius Werner von Siemens, and the inventor of one of the earliest ozone generators. In 1904, he moved as full professor to the University of Kiel, where he remained until 1916. During that time he published numerous papers on ozonolysis. His major publication detailing ozonolysis was published in Liebigs Ann. Chem. 1905, 343, 311. Dissatisfied with academic life and having failed to obtain either of two positions at universities, he left academia to become Director of Research at Siemens and Halske. He died on 3 November 1923 of complications following surgery for cancer.
Wilhelm Rudolph Fittig was a German chemist. Fittig discovered the pinacol coupling reaction, mesitylene, diacetyl and biphenyl. He studied the action of sodium on ketones and hydrocarbons. He discovered the Fittig reaction or Wurtz–Fittig reaction for the synthesis of alkylbenzenes, he proposed a diketone structure for benzoquinone and isolated phenanthrene from coal tar. He discovered and synthesized the first lactones and investigated structures of piperine naphthalene and fluorene.
Nikolay Nikolaevich Zinin was a Russian organic chemist.
Walter Julius Reppe was a German chemist. He is notable for his contributions to the chemistry of acetylene.
Heinrich Limpricht was a German chemist. Limpricht was a pupil of Friedrich Wöhler; he worked on the chemistry of furans and pyrroles, discovering furan in 1870.
Adolph Strecker was a German chemist who is remembered primarily for his work with amino acids.
Ulrich Schöllkopf was a German chemist and together with Georg Wittig discovered the Wittig reaction in 1956. Later in 1981 he published the synthesis method for amino acids known as the Bislactimether method or Schöllkopf method.
Hugo Weidel was an Austrian chemist known for inventing Weidel's reaction and describing the structure of organic compound niacin. For his achievements, Weidel received the Lieben Prize in 1880.
The Staudinger Synthesis, also called the Staudinger Ketene-Imine Cycloaddition, is a chemical synthesis in which an imine 1 reacts with a ketene 2 through a non-photochemical 2+2 cycloaddition to produce a β-lactam3. The reaction carries particular importance in the synthesis of β-Lactam antibiotics. The Staudinger Synthesis should not be confused with the Staudinger Reaction, a phosphine or phosphite reaction used to reduce azides to amines.
Werner Tochtermann is a German chemist and emeritus professor. From 1976 till his retirement in 1999 he was full professor of Organic Chemistry at the University of Kiel. His main areas of research were the chemistry of medium and large rings, the synthesis of cyclophanes, and the heteroquadricyclane→heteropin rearrangement, e.g. for the synthesis of oxepins from furans.
Heinrich Debus was a German chemist.
Georg Michael Hanack is Professor emeritus of Chemistry at the Eberhard Karls University, Tübingen (Germany).
Maria Lipp was a German organic chemist. She was the first female doctoral student, professor, and ordinary professor at the RWTH Aachen University.