Decomposition of diacyl peroxides in HMPA—An electron transfer process

In hexamethylphosphoric triamide (HMPA),four representative diacyl peroxides,namely,benzoyl peroxide (1),Cyclopropylformyl peroxide (2),lauroyl peroxide (3) and trifluoroacetyl per-oxide (4),all decompose at rates much higher than those expected from their unimolecular thermal de-composition,and the corresponding carboxylic acids are formed in high yields (74—97%).Further-more,several radical colligation products formed from HMPA molecules can be identified.Evidently,the initial step in the reaction between a diacyl peroxide and the“solvent”HMPA involves an electrontransfer with the latter acting as the donor.