62985-52-8Relevant articles and documents
Practical one-pot preparation of ketones from aryl and alkyl bromides with aldehydes and DIH via Grignard reagents
Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
experimental part, p. 6557 - 6564 (2012/08/27)
Various diaryl ketones, alkyl aryl ketones, and dialkyl ketones were efficiently prepared in good yields by the reactions of the Grignard reagents derived from aryl or alkyl bromides, followed by the reactions with aromatic or aliphatic aldehydes and the subsequent treatment with 1,3-diiodo-5,5- dimethylhydantoin and K2CO3, in a one-pot method. The same treatment of aromatic bromides bearing electron-withdrawing groups, such as ester, nitrile, ketone, and nitro groups with i-PrMgCl·LiCl or PhMgCl instead of Mg, also provided the corresponding diaryl and alkyl aryl ketones in good yields. The above methods are simple and practical transition-metal-free methods for the preparation of various diaryl ketones and alkyl aryl ketones bearing electron-rich aromatic groups and electron-deficient aromatic groups, as well as dialkyl ketones.
Preparation of polyfunctional arylmagnesium, arylzinc, and benzylic zinc reagents by using magnesium in the presence of LiCl
Piller, Fabian M.,Metzger, Albrecht,Schade, Matthias A.,Haag, Benjamin A.,Gavryushin, Andrei,Knochel, Paul
supporting information; experimental part, p. 7192 - 7202 (2010/03/05)
The presence of LiCl considerably facilitates the insertion of magnesium into various aromatic and heterocyclic bromides. Several functional groups, such as -OBoc, -OTs, -Cl, -F, -CF3, -OMe, -NMe2, and -N 2NR2, are well tolerated. The presence of a cyano group leads in some cases to competitive reduction of the organic halide to the corresponding ArH compound. The presence of sensitive groups such as methyl or ethyl ester is tolerated upon in situ trapping of the intermediate magnesium reagent with ZnCl2. This method can also be applied to the preparation of functionalized benzylic zinc reagents from benzylic chlorides. In the case of di- or tribromoaryl derivatives, directing groups such as -OPiv, -OTs, -N2NR2, or -OAc orient the zinc insertion (Zn/LiCl) to the ortho-position, while the reaction with Mg/LiCl or Mg/LiCl/ZnCl 2 leads to regioselective insertion into the para-carbon-bromine bond. Large-scale experiments (20-100 mmol) for all of the metalation procedures are described.
Convenient preparation of polyfunctional aryl magnesium reagents by a direct magnesium insertion in the presence of LiCl
Piller, Fabian M.,Appukkuttan, Prasad,Gavryushin, Andrei,Helm, Matthew,Knochel, Paul
supporting information; experimental part, p. 6802 - 6806 (2009/04/06)
(Chemical Equation Presented) In the footsteps of Victor Grignard: The simple LiCl-mediated insertion of magnesium into aryl chlorides and bromides at moderate temperatures leads to functionalized organomagnesium reagents (see scheme). An unprecedented range of functional groups may be present in the substrates (e.g. CN, CO2R, OTs, OBoc; Ts=p-toluenesulfonyl, Boc=tert-butylcarbonyloxy).
