Evidence for a methylenethioxophosphorane (thiophosphene) intermediate in nucleophilic substitution at a benzylthiophosphonyl centre
作者:Michael P. Coogan、Martin J. P. Harger
DOI:10.1039/c39900001745
日期:——
The remarkably high rate of the reaction of p-NO2C6H4CH2P(S)(NMe2)Cl with Et2NH, the presence of deuterium in the benzylic methylene group of the product formed with Et2ND, and the relative lack of discrimination between competing Me2NH and Et2NH, suggest an elimination–addition mechanism for substitution, with a three-coordinate PV methylenethioxophosphorane (thiophosphene) intermediate 6.
Stereochemical evidence for elimination–addition and a methylenethioxophosphorane (thiophosphene) intermediate in nucleophilic substitution at the PS centre of a benzylic phosphonamidothioic chloride
作者:Martin J. P. Harger
DOI:10.1039/a806926c
日期:——
The two diastereoisomers of ArCH2P(S)(NMeR*)Cl (Ar = 4-NO2C6H4, R* = CHMePh) react with Et2NH (0.2 mol dmâ3) in CH2Cl2 to give mixtures of the diastereoisomers of ArCH2P(S)(NMeR*)NEt2 in practically the same ratio (54.5:45.5 or 53:47); such non-stereospecificity points to a thiophosphene intermediate ArCHP(S)NMeR* as the product-forming species.