Abstract#R##N##R##N#The reaction mechanism of the model cytochrome P450-mediated desulfuration of thiophosphoryl trifluoride, trimethylphosphine sulfide, and trimethyl phosphorothionate was examined by the semiempirical MNDO-PM3 molecular orbital method. The proposed pathways, involving initial formation of S-oxide followed by rear-rangement to a cyclic phosphoxathiirane and the successive liberation of atomic sulfur to form a phosphate derivative, wee stepwisely analyzed by using the two model active oxygen species, O(1D) and O(3P). Reaction coordinate analysis followed by refinement of transition states in each spin state strongly suggested that the desulfuration of thiophosphorus compounds by O(3P) was energetically more favorable than O(1D). The alternative triplet pathway, abstraction of sulfur by O(3P) forming phosphine and sulfur monoxide followed by recombination between phosphorus and oxygen, was found to be energetically more probable than the rearrangement pathway. © 1993 by John Wiley & Sons, Inc.
['Toshiyuki Katagi']
MNDO-PM3 study on model cytochrome P450-mediated desulfuration of thiophosphoryl trifluoride, trimethylphosphine sulfide, and trimethyl phosphorothionate