Brønsted acidic ionic liquid accelerated halogenation of organic compounds with N-halosuccinimides (NXS)

Document Type

Article

Publication Date

1-1-2013

Abstract

The Brønsted-Acidic ionic liquid 1-methyl-3-(4-sulfobutyl) imidazolium triflate [BMIM(SO3H)][OTf] was demonstrated to act efficiently as solvent and catalyst for the halogenation of activated organic compounds with N-halosuccinimides (NXS) under mild conditions with short reaction times. Methyl aryl ketones were converted into a-halo and a,a-dihaloketones, depending on the quantity of NXS used. Ketones with activated aromatic rings were selectively halogenated, however in some cases mixtures of a-halogenated ketone and ring-halogenated ketones were obtained. Activated aromatics were regioselectively ring halogenated to give mono- and dihalo-substituted products. The [BMIM(SO3H)][OTf] ionic liquid (IL-A) was successfully reused eight times in a representative monohalogenation reaction with no noticeable decrease in efficiency. An effective halogenation scale-up in this IL is also presented. The reactivity trend and the observed chemo- and regioselectiivities point to an ET process in these IL-promoted halofunctionalization reactions. © 2013 by the authors.

Publication Title

Molecules

Volume

18

Issue

1

First Page

74

Last Page

96

Digital Object Identifier (DOI)

10.3390/molecules18010074

PubMed ID

23344189

E-ISSN

14203049

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