Diaeyl peroxides

In general, aliphatic diacyl peroxide initiators should be considered as sources of alkyl, rather than of aeyloxy radicals. With few exceptions, aliphatic acyloxy radicals have a transient existence at best. For certain diacyl peroxides (36) where R is a secondary or tertiary alkyl group there is controversy as to whether loss of carbon dioxide occurs in concert with 0-0 bond cleavage. Thus, ester end groups observed in polymers prepared with aliphatic diaeyl peroxides are unlikely to arise directly from initiation, but rather from transfer to initiator (see 3.3,2.1.4),... 

The rates of decomposition of peroxyesters (38) arc very dependent on the nature of the substituents R and R. The variation in the decomposition rale with R follows the same trends as have been discussed for the corresponding diaeyl peroxides (see 3.3.2.1.1). 

Fluorinated diaeyl peroxides have acquired an important role in organo-fluorine chemistry and have become the subject of intensive research.202-204 Bis(per)fluoroaIkanoyI or -aroyl peroxides are generally synthesized in excellent to moderate yields in the same manner as for nonfluorinated peroxides, that is by reaction of acid chlorides or anhydrides with sodium peroxide or hydrogen peroxide.205-206 Similarly, perfluoroalkanoyl chlorides and fluorides, many of which are accessible by industrial processes, react with hydrogen peroxide in the presence of hydroxide to give the diacyl peroxides l.206-207... 

Diaeyl peroxides, R( oO( r. Preparation (a) RCOCl -F NajOzl (b) RCOCI + H2O2 + NaOH. Use for alkylation of 2-hydroxy-1,4-naphthoquinone. The reaction... 

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