EPR studies on phosphoryldithioformates .2.

The addition of a variety of radicals to triphenylmethyl 1, allyl 2, benzyl 3 and but-3-enyl (diethoxyphosphoryl)dithioformate 4 has been investigated by EPR spectroscopy, Reactions with the first substrate always led to displacement of the triphenylmethyl radical; release of the allylic or benzylic moieties from 2 and 3 was observed above 243 K under photolytic conditions, while at lower temperatures or in the dark the adducts resulting from thiophilic addition of the radicals were detected. The weak EPR spectra detected when reacting dithioformates 1-4 and methyl(diethoxyphosphono)-dithioformate 5 with Grignard reagents are attributed to the radical anions of the starting compounds and to their ion pairs with magnesium cations.