Reactions of dithiadiphosphetane disulfides with organonitrogen compounds.

The reactions of (RP)-P-1(S)S2P(S)R-1 (R-1 = ferrocenyl) with a range of organic systems containing unsaturated C-N linkages have been studied. Thus treatment with dimethylcyanamide gives a 1,3,5,4-thiazaphosphorine 4-sulfide, whereas reaction with dicarbodiimides gives a thiazadiphosphetane. Furthermore reaction of diphenylurea gives a phenylthiazaphosphetane. Mechanisms for the reactions are proposed and the crystal structures of three selected examples are reported and discussed with reference to the steric effects of the reactants. These reactions provide a new entry into C-P-S-N heterocycles. Cyclic voltammetry studies on a range of ferrocenyl substituted heterocycles were also made.