19480-93-4Relevant articles and documents
Method for preparation of salts of hydroxy-substituted aromatic compounds
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Page/Page column 10-12, (2008/06/13)
A method for preparing a metal salt of a hydroxy-substituted aromatic compound is described. The method comprises contacting in an aqueous medium at least one hydroxy-substituted aromatic compound with a base comprising a metal cation to provide a mixture comprising water and a metal salt of said hydroxy-substituted aromatic compound. The aqueous metal salt is then contacted with a substantially water-immiscible solvent at a temperature greater than the boiling point of water at the prevailing pressure to provide a slurry comprising the metal salt of the hydroxy-substituted aromatic compound and a vapor stream comprising the water-immiscible solvent and water. The components of the vapor stream are separated using a vapor handling system comprising a partial reflux condenser to provide a water-rich component and a water immiscible solvent-rich component.
Reaction of Aryl and Vinyl Halides with Zerovalent Nickel-Preparative Aspects and the Synthesis of Alnusone
Semmelhack, M.F.,Helquist, Paul,Jones, L.D.,Keller, Leonard,Mendelson L.,et al.
, p. 6460 - 6471 (2007/10/02)
Zerovalent nickel complexes such as bis(1,5-cyclooctadiene)nickel and tetrakis(triphenylphosphine)nickel react rapidly with aryl and vinyl halides to produce the symmetrical coupling products, a low-temperature analogue of the Ullman reaction.The reaction proceeds through oxidative addition of the organic halide to Ni(0), and the reactivity of the Ni(II)intermediates has been examined.Arylnickel halide complexes decompose rapidly to biaryls in DMF.The coupling of simple vinyl halides proceeds with isomerization of the double bond but 3-haloacrylates give efficient co upling with retention of geometry.Cyclizations to form ortho-bridged biaryls are efficient in simple cases (6-, 7-, 8-, 9-, 10-, and 14-membered rings) but fail with an ortho-disubstituted case.The 13-membered meta-bridged cyclic biphenyl, alnusone, is prepared efficiently with the crucial aryl halide coupling to form the ring proceeding in 50percent yield.A side reaction promoted by the presence of protons and with certain ortho-substituted aryl halides is reduction of the aryl halide to the arene.This process can be enhanced by deliberate addition of acid during reaction with Ni(0) and a series of aryl halides underwent succesful reduction.
