Rhodium
(Chief Bee)
01-23-04 11:40
No 484227
      Allyl-Br/CuI/PhNO2/PhMgBr -> Allylbenzene (84%)
(Rated as: excellent)
    

The reaction of the phenyl-copper-magnesium reagent, prepared from 2 PhMgBr and CuI, with some organic halides
Mohammed T. Rahman and Syeda K. Nahar
Journal of Organometallic Chemistry 329, 133-138 (1987) (../rhodium /cu-grignard.coupling.html)

Abstract
The reagent prepared from 2 PhMgBr and CuI reacts with allyl and benzyl bromides to give allylbenzene and diphenylmethane, respectively, in 52 and 62% yields. The yields rise to 82-84% in the presence of nitrobenzene as an oxidant. During the reaction with allyl bromide some copper-bromine exchange takes place. Methyl iodide reacts with the copper reagent to give toluene in 65% yield. Iodoarenes react slowly and give poorer yields of the biaryls (18-46%); in these reactions some metal-iodine exchange is observed. Nitrobenzene seems to be better as an oxidant than copper(II) chloride, which brings about some metal-chlorine exchange in addition to acting as an oxidant.

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