Imidazolines

Imidazolines are a chemical group from the field of heterocyclic compounds and belong to the group of azolines . Its members are five-membered cyclic organic unsaturated compounds that have exactly two non-adjacent nitrogen atoms in the ring structure. They are derived from the imidazoles by hydrogenation of a double bond and are isomeric to the pyrazolines . There are three basic structures of the imidazolines, which are isomeric to one another and differ in the position of the double bond.

Structural formulas of the three parent systems of the imidazolines ( 2-imidazoline , 3-imidazoline and 4-imidazoline )

Imidazolines can form stable carbenes . For this purpose, imidazoles substituted on both nitrogen atoms can be reduced with sodium hydride and potassium tert -butanolate . The resulting carbenes are stable and are called Arduengo carbenes . These carbenes can be used, for example, as ligands on Grubbs catalysts .

Common Arduengo carbene for the synthesis of Grubbs ligands

Web links

• Synthesis of 2-imidazolines

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1. ^ H. Beyer, W. Walter: Textbook of Organic Chemistry , 23rd Edition, S. Hirzel Verlag, Stuttgart 1998, pp. 795-896, ISBN 3-7776-0808-4 .
2. ↑ M. Scholl, S. Ding, CW Lee, RH Grubbs: Synthesis and Activity of a New Generation of Ruthenium-Based Olefin Metathesis Catalysts Coordinated with 1,3-Dimesityl-4,5-dihydroimidazol-2-ylidene Ligands , in: Organic Letters 1999 , 1 , 953-956; doi: 10.1021 / ol990909q .