29682-41-5Relevant articles and documents
Directed magnesiation of polyhaloaromatics using the tetramethylpiperidylmagnesium reagents TMP2Mg×2 LiCl and TMPMgCl×LiCl
Unsinn, Andreas,Rohbogner, Christoph J.,Knochel, Paul
supporting information, p. 1553 - 1560 (2013/06/27)
A convenient and efficient functionalization of polyhaloaromatics via regioselective magnesiation has been developed. Starting from simple, inexpensive but structurally challenging arenes, metallation by magnesium amide bases was achieved under mild conditions. The desired Grignard reagents were stable towards aryne formation, were obtained in good yields within short reaction times and could be reacted with a variety of typical electrophiles, providing attractive, functionalized building blocks in good to excellent yields. As an application we have prepared the antimicrobial natural product 2,6-dichloro-3-phenethylphenol isolated from the New Zealand liverwort Riccardia marginata. This synthesis involves a mixed bimetallic compound prepared via metallation of a phenylboronic acid pinacol ester derivative and subsequent selective cross-coupling. Copyright
General copper-catalyzed transformations of functional groups from arylboronic acids in water
Yang, Haijun,Li, Yong,Jiang, Min,Wang, Junmei,Fu, Hua
experimental part, p. 5652 - 5660 (2011/06/23)
A simple and general copper-catalyzed method has been developed for transformations of various functional groups (i I, i N3, i SO2R, i OH, i NH2, and i NO 2) on aromatic rings from arylboronic acids in water under air. The protocol uses cheap and readily available inorganic salts (KI, NaN3, NaSO2R, NaOH, NaNO2) and aqueous ammonia as the functional-group sources, simple Cu2O/NH3 as the catalyst system, environmentally friendly water as the solvent, and oxygen in air as the oxidant. Importantly, the copper catalyst system in water was recyclable. This study should provide a useful strategy for interconversions of the functional groups on aromatic rings.
Nucleophilic Displacement in Polyhalogenoaromatic Compounds. Part 11. Kinetics of Protiodeiodination of Iodoarenes in Dimethyl Sulphoxide-Methanol
Bolton, Roger,Moore, Clive,Sandall, John P.B.
, p. 1593 - 1598 (2007/10/02)
The rates of methoxide-ion induced protiodeiodination of a number of polychloroiodobenzenes and their derivatives have been measured in dimethyl sulphoxide-methanol (9:1 v/v; 323.2 K).The true reagent under these conditions appears to be the dimethyl sulphoxide anion, and the rates of reaction in some cases appear to approach that expected of a diffusion controlled process.This corresponds to a major decrease in the efficacy of further activating substituents in the aromatic system, altough deactivating groups such as p-OMe still show large effects.Chlorine promotes protiodeiodination in the order of efficiency o-Cl > m-Cl > p-Cl; the trifluoromethyl group activates displacement in the order o-CF3 > p-CF3 > m-CF3, although with much less difference between isomeric sites. o-Nitro-groups promote protiodeiodination whereas the p-nitro-group encourages methoxydeiodination.No evidence of methoxydeiodination was found in attack of the polychloroiodobenzenes, although the rates of methoxydechlorination of the corresponding polychlorobenzenes suggest that in some cases this might occur.Evidence rejecting the possible SRN1 mechanism and supporting nucleophilic attack by a carbanionic species upon iodine is presented.
