99668-17-4Relevant academic research and scientific papers
The preparation and properties of some α-acyloxy- and α-carbamoyloxy-phosphonothionates
Hudson, Harry R.,Jaszay, Zsuzsa M.,Pianka, Max
, p. 1571 - 1582 (2003)
New α-acyloxy and α-carbamoyloxy derivatives of dimethyl 2,2,2-trichloroethyl-phosphonothionate have been prepared, characterized, and screened for activity against free-living soil nematodes. Several of the more easily hydrolysable esters, and also the N-methylcarbamoyl derivative, were as active as the parent pesticide, dimethyl α-hydroxy2,2,2-trichloroethylphosphonothionate, after an induction period during which the active species is assumed to be released in vivo. It is concluded that the 2,2,2-trichloroethyl group is essential for activity in compounds of these types and that the presence of the N-methylcarbamoyl group does not in itself confer activity.
The Nature of Cationic Intermediates Derived from α-Thiophosphoryl and α-Thiocarbonyl Mesylates. Neighboring Thiophosphoryl and Thiocarbonyl Participation
Creary, Xavier,Mehrsheikh-Mohammadi, M. E.
, p. 7 - 15 (2007/10/02)
A series of mesylate derivatives of α-hydroxy thiophosphonathes, RCH(OMs)PS(OEt)2 (8), have been prepared.These mesylates can react by kc processes under solvolytic conditions if cation stabilizing groups such as p-anisyl or p-thioanisyl groups are present.However, under conditions of appropriate electron demand, mesylates 8 can react by kΔ processes involving thiophosphoryl participation.The cyclic intermediate ions capture acetic acid at phosphorus and lead ultimately to α-thio acetate derivatives of phosphonates.This overall transformation converts the P=S function to the P=O group.Rates of acetolyses of 8 can exceed those of the O-phosphoryl analogues by large factors when kΔ processes are involved (as expected for anchimerically assisted processes).Mesylate derivatives of α-hydroxy thio esters, R2C(OMs)CSOCH3 (9), can also react by kΔ processes as shown by enhanced rates relative to simple ester analogues.The substrate (R)-(-)-PhCH(OMs)CSOCH3 (38) gives an acetolysis product that is largely retained, while 9 (R = Me) gave a large fraction of a rearranged product.These data all argue in favor of neighboring thiocarbonyl participation in 8, giving cyclized intermediate cations.The behavior of mesylates 8 and 9 can therefore be quite different from that of the corresponding O-phosphoryl and carbonyl analogues.Neighboring group participation in 8 and 9 accounts for the differences.The contrasting behavior of 8 and 9 also argues against neighboring phosphoryl or carbonyl participation in solvolyses of mesylate derivatives of α-hydroxy phosphonates or α-keto mesylates.
