nightflight
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Corey House reaction
Hi,
I just realized that it´s not possible to use Grignard in a coupling rxn of an aryl halide and a alkyl halide.
So I´ve stumbeled across the Wurtz Fittig reaction, that uses Sodium as a halide exchanging agent and couples the two species together with the salt
as the leaving group.
The problem with the Corey House reaction is that the Gilman reagent seems hard to get (if I´m wrong, please correct me, also if there´re
substitutes or new ways like ec/mv), the W F rxn has low yields and a lot of byproducts, but maybe it´s worth it, for the relatively easy procedure?
Are there any other ways of coupling aryl halides with an alkane or alkene(halide)?
nightflight
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XxDaTxX
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"Gilman reagent seems hard to get" ...
Yes and no. Alkyl halide -> Alkyl lithium -> add it to CuI and you have your reagent (oversimplified .... keep reading). However .... I
wouldn't do this outside of a well equiped lab. Argon shielding is a requisite in most workplaces.
Tetramethylenediamine allows selective coupling of an alkylhalide to an aryl Grignard using FeCl3 as catalyst. Search the literature. IIRC the
yields were effectively quantitative, both in the literature and in our application.
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nightflight
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I´ve just read that grignard is possible in coupling the reagents with the corresponding halide and this even without cooling, but the
Metallcatalized reaction with FeCl3 seems to be very attractiver, too, it´s only that I´ve found stub articles of it.
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XxDaTxX
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| Quote: | Originally posted by nightflight
I´ve just read that grignard is possible in coupling the reagents with the corresponding halide and this even without cooling |
Possible, yes. Efficient, no.
Think dehydrohalogenation.
Iron-Catalyzed Cross-Coupling of Primary and Secondary Alkyl Halides with Aryl Grignard Reagents
J. Am. Chem. Soc., 126 (12), 3686 -3687, 2004. 10.1021/ja049744t S0002-7863(04)09744-6
[Edited on 22-2-2007 by XxDaTxX]
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