Electron transfer reactions between trivalent phosphorus compounds and activated ketones

The present paper presents a mechanism for the reaction between trivalent phosphorus compounds - P(OR)3, R = alkyl and P {N(CH3)2}3 - and molecules with activated carbonyl groups such as -diketones, o-quinones and ,ß-unsaturated ketones. It appeared from ESR measurements that intermediate radicals which originate in a high concentration are converted into oxyphosphoranes. In the case of P(OR)3 an intramolecular shift could be established as a side reaction. Furthermore a number of interesting spin adducts are formed between phosphinium radicals and the scavenger 2-methyl-2-nitrosopropane.