Hans Meerwein (May 20, 1879 in

Hamburg (male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal ...

, Germany – October 24, 1965 in

Marburg Marburg ( or ) is a university town in the German federal state (''Bundesland'') of Hesse, capital of the Marburg-Biedenkopf district (''Landkreis''). The town area spreads along the valley of the river Lahn and has a population of approximate ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

) was a German

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

. Several reactions and reagents bear his name, most notably the

Meerwein–Ponndorf–Verley reduction The Meerwein–Ponndorf–Verley (MPV) reduction in organic chemistry is the reduction of ketones and aldehydes to their corresponding alcohols utilizing aluminium alkoxide catalysis in the presence of a sacrificial alcohol. The advantages of th ...

, the

Wagner–Meerwein rearrangement A Wagner–Meerwein rearrangement is a class of carbocation 1,2-rearrangement reactions in which a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. They can be described as cationic ,2sigmatropic rearrangements, p ...

, the

Meerwein arylation The Meerwein arylation is an organic reaction involving the addition of an aryl diazonium salt (ArN2X) to an electron-poor alkene usually supported by a metal salt. The reaction product is an alkylated arene compound. The reaction is named afte ...

reaction, and Meerwein's salt.

Life and work

His father was the architect, Wilhelm Emil Meerwein. He originally trained to be a chemistry technician or 'chemotechnician' at the Fresenius University of Applied Sciences (between 1898 and 1900) before studying for a chemistry degree at the

University of Bonn The Rhenish Friedrich Wilhelm University of Bonn (german: Rheinische Friedrich-Wilhelms-Universität Bonn) is a public research university located in Bonn, North Rhine-Westphalia, Germany. It was founded in its present form as the ( en, Rhine U ...

. After finishing his PhD with Richard Anschütz he worked at the

University of Berlin Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative o ...

, before returning to Bonn where he became professor in 1914. From 1922 till 1928 he was professor for organic chemistry at the

University of Königsberg The University of Königsberg (german: Albertus-Universität Königsberg) was the university of Königsberg in East Prussia. It was founded in 1544 as the world's second Protestant academy (after the University of Marburg) by Duke Albert of Prussi ...

. The last change in his academic career was to the

University of Marburg The Philipps University of Marburg (german: Philipps-Universität Marburg) was founded in 1527 by Philip I, Landgrave of Hesse, which makes it one of Germany's oldest universities and the oldest still operating Protestant university in the wor ...

. The war devastated the Institute and Meerwein was planning the rebuilding which was finished in 1953, the year he retired from lecturing. He conducted experimental work with the help of two postdocs until his death in 1965. His greatest impact upon organic chemistry was to propose the

carbocation A carbocation is an ion with a positively charged carbon atom. Among the simplest examples are the methenium , methanium and vinyl cations. Occasionally, carbocations that bear more than one positively charged carbon atom are also encountere ...

2 as a reactive intermediate, originally as a rationalization of the

racemization In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into a racemic (optically inactive) form. This creates a 1:1 molar ratio of enantiomers and is referred too as a racemic mixture (i.e. conta ...

isobornyl chloride Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an '' endo'' position. The exo diastereomer is called isoborneol. Being chiral, borneol exists as enantiomers, both of which are fou ...

1 catalysed by a Lewis acid such as SnCl₄. His proposed mechanism for racemization involved a subsequent ,6

hydride In chemistry, a hydride is formally the anion of hydrogen( H−). The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride ...

transfer, which allows the carbocation to be located at either of these two symmetric positions. An alternative mechanism—a ,2methyl migration, a type of reaction now known as a Wagner–Meerwein shift—was in fact suggested for the first time by

Josef Houben Heinrich Hubert Maria Josef Houben (27 October 1875, in Waldfeucht ( Rheinland) Germany – 28 June 1940, in Tübingen) was a German chemist. He made achievements within ketone synthesis, terpenes, and camphor studies. After being wounded severa ...

and Pfankuch.

Awards

*1959 Otto Hahn Prize for Chemistry and Physics

References

External links

Honors for Meerwein in Marburg
{{DEFAULTSORT:Meerwein, Hans 1879 births 1965 deaths 20th-century German chemists University of Bonn alumni University of Bonn faculty Commanders Crosses of the Order of Merit of the Federal Republic of Germany Scientists from Hamburg