N′-Activation of N-Arylimidazoles: Facile Syntheses of N-Alkyl-N′-aryl­imidazolium Iodides from Less Expensive Chloro Substrates

Abstract

A series of N,N′-asymmetrically substituted imidazolium iodide salts have been synthesized, starting from N-arylimidazoles and the less expensive, but less reactive, 1-chlorobutane or (3-chloropropyl)trimethoxysilane. The addition of potassium iodide and the use of 1,2-dimethoxyethane as a solvent lead to multigram quantities of these salts becoming readily available, in yields ranging from 50% to 94%. Direct combination of (3-chloropropyl)trimethoxysilane with 1-mesityl-1H-imidazole was also effected, in good yield, by using a microwave oven at 180 ˚C. The synthesis of two 1-alkyl-3-isopropylimidazolium chlorides is also presented herein.

Key words

arylimidazoles - imidazolium salts - trimethoxysilyl - chloroalkyls - N-heterocyclic carbenes

References

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