Wagner-Jauregg reaction

The Wagner-Jauregg reaction is a name reaction in organic chemistry . It was named after its discoverer, the Austrian chemist Theodor Wagner-Jauregg (1903–1992). The Wagner-Jauregg reaction is a special case of the Diels-Alder reaction , in which a diarylethene is reacted with maleic anhydride . This creates a new aromatic ring system between the phenyl group and the ethene, so that a naphthalene group is formed. This allows aromatics to be synthesized with new and multiple ring systems.

Overview reaction

In this synthesis a diarylethene, with the radicals R ¹ for hydrogen, alkyl or aryl radical (e.g. a phenyl radical) and R ² for hydrogen, bromine or chlorine, is reacted with maleic anhydride in a double Diels-Alder reaction . In a cycloaddition reaction, s maleic anhydride is added, producing a naphthalene derivative:

Reaction mechanism

The postulated reaction mechanism comes from the book "Comprehensive Organic Name Reactions and Reagents" and is shown here as an example:

The diarylethene enters into a Diels-Alder reaction with the maleic anhydride , in which case there is a suprafacial ring closure and the carboxylic acid anhydride 1 is formed . Another Diels-Alder reaction, in which a ring closure takes place between 1 and maleic anhydride, forms the carboxylic acid anhydride 2 . In the next two steps, a rearomatization takes place with elimination of hydrogen and maleic anhydride. This ultimately creates an aromatic carboxylic acid anhydride 3 .

Individual evidence

^ Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set , John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 2926.
↑ Theodor Wagner-Jauregg: The addition of maleic anhydride to asymmetric diphenyl-ethylene . In: Justus Liebig's Annals of Chemistry . 491, No. 1, 1931, pp. 1-13. doi : 10.1002 / jlac.19314910102 .
↑ ^a ^b Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 2927.
↑ M. Windholz (Ed.): The Merck Index, Ninth Edition . Merck & Co., 1976, ISBN 0-911910-26-3 , p. ON-91.

[Wang-1] Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set , John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 2926.

[2] Theodor Wagner-Jauregg: The addition of maleic anhydride to asymmetric diphenyl-ethylene . In: Justus Liebig's Annals of Chemistry . 491, No. 1, 1931, pp. 1-13. doi : 10.1002 / jlac.19314910102 .

[Wang_1477-3] Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , p. 2927.

[Windholz_1477-4] M. Windholz (Ed.): The Merck Index, Ninth Edition . Merck & Co., 1976, ISBN 0-911910-26-3 , p. ON-91.