Ethers, aliphatic alkoxylation

Linear ethoxylates are tine preferred raw materials for production of ether sulfates used in detergent formulations because of uniformity, high purity, and biodegradahility, The alkyl chain is usually in the C y. to Cy range having a molar ethylene oxide alcohol ratio of anywhere from 1 1 to 7 1. Propoxylates, ethoxylates, and mixed alkoxylates of aliphatic alcohols or alkyl phenols are sulfated for use in specialty applications. 

Hydroxy ethers in which the alkoxyl group is on an aromatic nucleus or an aliphatic chain have been made from alk oxy Grignard reagents in about 50% yields. 

Substitution of an amino for the alkoxyl group of simple aliphatic ethers has little preparative importance the ether linkage must be weakened by a carbonyl, carboxyl, or nitrile group in the -position if the reaction is to occur under not too drastic conditions. Certain /8-methoxy ketones of type (17) can be converted into / -amino ketones below 100°.1081 Cleavage of the ether group in activated enol ethers is still easier for instance, 2-(acetoxymethylene)-... 

Quinoline directs alkoxylation and phenoxylation of tethered arenes. The 8-aminoquinoline directs the copper oxidation of the sp C-H bond (Scheme 76) (130L5842). A number of alcohols are tolerated, including both aliphatic (6 examples 39-85%) and aromatic alcohols (9 examples, 59-88%).The aryl amides can also have a range of functional groups including cyano, nitro, alkoxy, and alkyl groups. Picolinic acid derivatives also direct oxidative formation of the ether. 

Oxygen is intermediate in its ability to influence either aliphatic ether attraction of an electron pair initiated by the localized positive charge on the oxygen can form the alkyl ion and the alkoxyl radical in this case the charge site is moved (Equation 4.22 see Figure 3.9). Note that the bond cleaved (R —CH2—OR) is not that cleaved by the radical-site initiation... 

The aryl ether formation was, until the late 1990s, the domain of copper-catalyzed processes, namely the Ullmann reaction. Around 15 years ago, Hartwig and Buchwald independently discovered the palladium-catalyzed alkoxylation of aryl halides with phenols. Later, these reactions were extended to aliphatic alcohols and to hydroxide as nucleophiles (vide infra. Scheme 5-159). The mechanism of the reductive elimination has been elucidated on isolated complexes. ... 

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