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Organic peracids behave as a source of alkyl radicals and serve as a good model for studying their chemistry. The OH transfer by alkyl radicals and the stereoelectronic control of the reaction were investigated in detail. Inter- and the intramolecular hydrogen shifts by alkyl radicals were also studied. These results were used in order to undertake selective hydroxylation of hydrocarbons. Finally we turned our attention to the reactivity of electrophilic radicals towards peracids.

Organic peracids behave as a source of alkyl radicals and serve as a good model for studying their chemistry. The OH transfer by alkyl radicals and the stereoelectronic control of the reaction were investigated in detail. Inter- and the intramolecular hydrogen shifts by alkyl radicals were also studied. These results were used in order to undertake selective hydroxylation of hydrocarbons. Finally we turned our attention to the reactivity of electrophilic radicals towards peracids.

The structure, stability and reactivity of HX⋯H 2 and HXCH 2 ⋯H 2 (X = O, S) were studied using standard ab-initio MO calculations including electron correlation (MP2, MP3, PMP3, MP4). In the most stable conformation of HX⋯H 2 , the H-X bond is antiparallel to one α-CH bond. The predicted height for the rotational barrier around the HX-·CH 2 bond is ca. 4 kcal mol t1 for both radicals (X = O, S). The inversion barrier around the radical centre is weak in HO⋯H 2 (⋍ 1 kcal mol −1 ) and becomes negligible in HS⋯H 2 . The best conformation around the HX-CH 2 ⋯H 2 bond is the gauche one for both radicals (X = O, S), but the best conformation around C-C is reached when the SOMO is antiparallel to one /gb-CH if X = O, or antiparallel to C-X if X = S. HOCH 2 ⋯H 2 is slightly more stable than HS⋯H 2 , but CH 3 S . is much more stable than CH 3 O . . HOCH 2 ⋯H 2 is slightly less stable than HSCH 2 ⋯H 2 . The easy 1,2-migration of HS in HSCH 2 ⋯H 2 clearly depends on the weak bond-dissociation energy of HS-CH 2 ⋯H 2 . A direct 1,2-H shift in HX⋯H 2 is energetically costly.