Sodium phenoxide, reaction with halides

Ethers can be prepared by reaction of an alkoxide or phenoxide ion with a primary alkyl halide. Anisole, for instance, results from reaction of sodium phenoxide with iodomethane. What kind of reaction is occurring Show the mechanism. 

Additional studies showed that iodoferrocene was approximately as reactive as l-iodo-2-nitrobenzene under Ullmann conditions. A mixed Ullmann reaction involving these two reactive aryl halides produced 2-nitrophenylferrocene. Ullmann condensations of iodoferrocene with various sodium phenoxides and sodium arenethiolates likewise led to ferrocenyl aryl ethers and sulfides, respectively (84, 85). 

It has been found that the use, as ligands, of electron-poor phosphines, such as 1,1 -bis(diphenylphosphino)ferrocene, enhances yields in the palladium-catalysed reaction of aryl bromides with sodium phenoxides to yield diaryl ethers.87 Palladium-catalysed coupling of ethynylated derivatives of bipyridine or terpyridine with the corresponding bipyridine or terpyridine halides or triflates has been used in the synthesis of preorganized polytopic ligands.88... 

As noted earlier in this section, aryl halides generally do not undergo substitution reactions. However, under conditions of high temperature and pressure, these compounds can be forced to undergo substitution reactions. For example, under high temperature and pressure, chlorobenzene can be converted into sodium phenoxide when reacted with sodium hydroxide. 

Phenols can be converted into esters by reaction with acid chlorides or acid anhydrides and into ethers by reaction with alkyl halides in the presence of base (Following fig.). These reactions can be done under milder conditions than those used for alcohols due to the greater acidity of phenols. Thus phenols can be converted to phenoxide ions with sodium hydroxide rather than metallic sodium. 

Since the groups participating in the ether linkage are not identical, the ether to be synthesized is a-symmetrical. One method of producing asjTnmetrical ethers is through the Williamson synthesis. In this reaction, an alkyl halide (or substituted alkyl halide) is allowed to react with a sodium alkoxide or a sodium phenoxide as shown ... 

Alkoxide or aryloxide anions are also reputed to be inactive in Sr I reactions. There is, however, one example of such a reaction at an sp carbon the nitro-derivative of 4-nitrocumyl reacts with phenoxide and 1-methyl-2-naphthoxide ions yielding the corresponding ethers (Kornblum et al., 1967). A similar reaction has been reported for halobenzenes in t-butyl alcohol upon stimulation by sodium amalgam (Rajan and Sridaran, 1977). This reaction could not, however, be reproduced (Rossi and Pierini, 1980) and other attempts to make phenoxide ions react at sp carbons have been equally unsuccessful (Ciminale et al, 1978 Rossi and Bunnett, 1973 Semmelhack and Bargar, 1980). It has been found, more recently, that phenoxide ions react with a series of aryl halides under electrochemical induction, but that the coupling occurs at the p- or o-phenolic carbon rather than at the phenolic oxygen (Alam et al, 1988 Amatore et al, 1988). This is... 

Alkyl-aryl ethers are often synthesized by carefully controlling solubility. Both the alkyl halide and phenol are dissolved in dichloromethane then the solution is mixed with an aqueous solution of sodium hydroxide. Phenol, a poor nucleophile, reacts with sodium hydroxide in the aqueous phase to form the phenoxide ion, a good nucleophile. Alkyl-aryl ethers can be synthesized by treating the sodium salt of a phenol with an alkyl halide. The following example illustrates the Williamson synthesis of allyl-aryl ethers. The Bu N+Br is used to facilitate reaction between the polar phenoxide salt and the hydrophobic alkyl halide in the mixed solvent. 

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