Carboxylic acids homogeneous reactions

The first vinyl ester prepared was vinyl acetate, in 1912, by homogeneous mercury sulfate catalysis [29]. For the vinyl esters of lower carboxylic acids, the reaction was soon carried out in the gas phase over, for example, zinc salts of the corresponding carboxylic acids (such as zinc acetate) heterogenized on active charcoal [30]. By 1965, vinyl acetate was prepared almost exclusively by this method. Since then, this synthesis has been largely superseded by the ace-toxylation of ethylene, the petrochemical preparation of which is highly economic (Section 2.1.4.1). 

Acylation can be effected by direct esterification with carboxylic acids. The reaction is performed with activating agents and a base, with A,A-dicyclohexylcarbodii-mide (DCC) serving as a powerful condensation agent. The homogeneous-phase... 

Polycarboxylated polyalkoxylates and their sulfate derivatives may be prepared by reacting an ethoxylated or propoxylated alcohol with a water-soluble, alkali or earth alkali metal salt of an unsaturated carboxylic acid [339]. The reaction occurs in aqueous solution in the presence of a free radical initiator and gives products of enhanced yield and reduced impurity levels, compared with the essentially anhydrous reactions with free carboxylic acids, which have been used otherwise. The method provides products that give solutions that are clear on neutralization, remain clear and homogeneous on dilution, and are useful as cleaning agents in drilling and other oil field operations. 

As with carboxylic acids obtained by palladium hydroxycarbonylation, their derivatives esters, amides, anhydrides and acyl halides are synthesized from alkenes, CO and HX (X = OR, NR2 etc.). The Pd-catalyzed methoxycarbonylation is one of the most studied reactions among this type of catalyzed carbonylations and has been reviewed and included in reports of homogeneous catalysis.625, 26 The methoxycarbonylation has been applied to many different substrates to obtain intermediates in organic syntheses as well as specific products. For instance, the reaction has been applied for methoxycarbonylation of alkynes666 Highly efficient homogeneous Pd cationic catalysts have been reported and the methoxycarbonylation of alkynes has been used to develop economically attractive and environmentally benign process for the production of methyl... 

In this paper we disclose the syngas homologation of carboxylic acids via ruthenium homogeneous catalysis. This novel homologation reaction involves treatment of lower MW carboxylic acids with synthesis gas (C0/H2) in the presence of soluble ruthenium species, e.g., Ru02, Ru3(C0)12, H4Ru4(C0)12, coupled with iodide-containing promoters such as HI or an alkyl iodide (1). 

More recently, the fixation efficiency on cotton of Cl Reactive Red 177 (7-43) and its 4-carboxyphenylazo analogue in the presence of various carbodiimides (including 7-44 and 7.45) was investigated, as well as homogeneous reactions of selected carboxylic acids with alcohols (including acetylcellulose in acetone). The carboxylated dye reacted more effectively with cotton cellulose in the presence of cyanamide rather than dicyandiamide,... 

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