Halides, aryl reaction with hydroxide

Table VIII shows the conversions and selectivities obtained in this reaction with the various bases. Both calcium and barium hydroxide, as well as potassium carbonate, gave good yields and selectivities, particularly barium hydroxide, which gave conversions near 100% after 14h in a batch reactor. Ba(OH)2 was tested as a basic catalyst for the reaction with other aryl halides such as iodobenzene and chlorobenzene, and in both cases the yield and selectivity were also excellent.

Aryl halides react readily with carbon monoxide, in the presence of hydroxide and palladium salt catalysts in DMF solution to give aryl carboxylates879. The reaction also occurs under photostimulation with either a cobalt880,881 or a nickel882 catalyst. Under higher pressures of carbon monoxide, aryl iodides give a-ketoacids883. 

Perfluoroalkynylcopper reagents can be prepared by metathesis reactions with the zinc or cadmium reagent (e.g., formation of 6) or by treatment of terminal (perfluoroalkyl)acetylenes with copper(I) chloride/ammonium hydroxide.69 Perfluoroalkynylcopper reagents react with aryl (e.g., formation of 7) and vinyl halides as well as undergoing oxidative dimerization reactions upon exposure to air.2... 

Interestingly, a host of aryl amines, including diphenylamine (Equation 10.23) and alkyl-substituted aryl amines can now readily be prepared from the corresponding aryl halides on reaction of the latter with amine using a palladium catalyst such as tri-t-butylphosphinepalladium(II) in toluene/water with potassium hydroxide (KOH) and an A, A, iv-trimethylcetylammonium bromide [Ci6H33N(CH3)3 Br ] phase transfer catalyst (Chapter 5). ... 

Copper-Catalyzed Reactions The use of Cul was explored in combination with several ligands for the coupling of aryl halides with hydroxide nucleophiles. In 2006, Leadbeater reported the coupling aryl halides with NaOH using CuI/L-proline in water under... 

The original conditions used amines as solvents or cosolvents. Several other bases can replace the amine. Tetrabutylammonium hydroxide or fluoride can be used in THF (see Entry 1 in Scheme 8.11).163 Tetrabutylammonium acetate is also effective with aryl iodides and EWG-substituted aryl bromides (Entry 2).164 Use of alkenyl halides in this reaction has proven to be an effective method for the synthesis of enynes165 (see also Entries 5 and 6 in Scheme 8.11). 

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