Acyl peroxides carboxylic acids

Acyl peroxides Carboxylic acid dialkoxy-methyl esters - alkoxyformic anhydrides... 

For the mechanism of azolide hydrolysis under specific conditions like, for example, in micelles,[24] in the presence of cycloamyloses,[25] or transition metals,[26] see the references noted and the literature cited therein. Thorough investigation of the hydrolysis of azolides is certainly important for studying the reactivity of those compounds in chemical and biochemical systems.[27] On the other hand, from the point of view of synthetic chemistry, interest is centred instead on die potential for chemical transformations e.g., alcoholysis to esters, aminolysis to amides or peptides, acylation of carboxylic acids to anhydrides and of peroxides to peroxycarboxylic acids, as well as certain C-acylations and a variety of other preparative applications. 

Most frequently the polymerization process is initiated by free radicals obtained through the decomposition of hydroperoxides, alkyl peroxides, dialkyl peroxides, acyl peroxides, carboxylic ester peracids, salts of (tetraoxo)sulphuric acid, hydrogen peroxide, aliphatic azo compounds and bifunctional azobenzoin initiators. The rate of decomposition of different initiators into free radicals depends on their stmcture and on temperature. A measure of the efficiency of the initiator in the pol5mierization process is the half-decomposition period. 

Similar additions have been successfully carried out with carboxylic acids, anhydrides, acyl halides, carboxylic esters, nitriles, and other types of compounds. These reactions are not successful when the alkene contains electron-withdrawing groups such as halo or carbonyl groups. A free-radical initiator is required, usually peroxides or UV light. The mechanism is illustrated for aldehydes but is similar for the other compounds ... 

Addition of carboxylic acids or acyl peroxides to alkenes... 

Recently, acylsilanes have been utilized as useful intermediates in organic synthesis [57], For example, treatment of acylsilanes with the fluoride ion generates the corresponding acyl anions which react with electrophiles. On the other hand, by using the electrochemical method, acylsilanes serve as acyl cation equivalents because nucleophiles are introduced at the carbonyl carbon. Chemical oxidation of acylsilanes with hydrogen peroxide which affords the corresponding carboxylic acids has been reported [58], However, the anodic oxidation provides a versatile method for the introduction of various nucleophiles... 

Reactions of O2 with esters R C(0)0R also pass nucleophilic substitution as an initial step (Sawyer and Gibian 1979). Final products are acyl peroxides or carboxylic acids. The following set of equations explains the product formation ... 

Reduction of carboxylic acids 9-42 Reduction of carboxylic esters 9-43 Reduction of carboxylic esters with titanocene dichloride 9-44 Reduction of anhydrides 9-45 Reduction of acyl halides 9-53 Reduction of nitriles 9-57 Reduction of hydroperoxides 9-60 Reduction of peroxides 9-69 Reaction between aldehydes and base (Cannizzaro)... 

Alkyl radicals for such reactions are available from many sources such as acyl peroxides, alkyl hydroperoxides, particularly by the oxidative decarboxylation of carboxylic acids using peroxy-disulfate catalyzed by silver. Pyridine and various substituted pyridines have been alkylated in the 2-position in high yield by these methods. Quinoline similarly reacts in the 2-, isoquinoline in the 1-, and acridine in the 9-position. Pyrazine and quinoxaline also give high yields of 2-substituted alkyl derivatives <74AHC(16)123). 

The highly acidic conditions required to generate peracids in situ from carboxylic acids and hydrogen peroxide are usually not conducive to efficient amine oxidation. In situ generation from anhydrides in neutral solution or other acylated agents in alkali can be employed. In situ perphthalic or permaleic have been reported for pyrimidine oxidation.332... 

Hydroboration of alkynylsilanes with dicyclohexylborane proceeds in a stereo-and regioselective manner, placing the boron at the silicon-bearing carbon. Oxidation of the resultant alkenylborane with excess alkaline hydrogen peroxide produces, via an acyl silane intermediate (see Section 7.9), the carboxylic acids in greater than 80% yields. The alkynylsilanes may be generated in situ as illustrated by the one-pot transformation below. 

Acyl peroxides from carboxylic acids via carboxylic acid chlorides... 

Acyl peroxides from carboxylic acid chlorides 2 COC1 —V CO-Og-OC s. 5,95... 

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