122183-03-3Relevant academic research and scientific papers
Solvent-dependent Stereoselectivity in the Non-stereospecific Reactions of the Diastereoisomers of a Phosphonamidothioic Chloride with tert-Butylamine. A Pointer to the Lifetime of the Thiometaphosphonimidate Intermediate
Harger, Martin J. P.
, p. 1057 - 1061 (2007/10/02)
The two diastereoisomers of N--P-tert-butylphosphonamidothioic chloride (9) give the same mixture of the diastereoisomers of the phosphonamidothioic diamide product (11) with i-PrNH2 or t-BuNH2 in dilute solution, i.e. reaction is completely non-stereospecific.The ratio of the diastereoisomers in the product differs significantly from 50:50, i.e. reaction is appreciably stereoselective.With t-BuNH2 the stereoselectivity increases markedly on going from a solvent of high polarity (MeCN or Me2CO) to one of low polarity (CHCl3 or cyclohexane), but with i-PrNH2 it changes relatively little.In i-PrNH2-t-BuNH2 competition experiments the NHi-Pr/NHt-Bu product ratio also increases substantially as the polarity of the solvent decreases.These observations are thought to indicate reaction via a 3-co-ordinate P(V) thiometaphosphonimidate intermediate that exists long enough not only to become liberated, but also, in less polar solvents, to experience unsuccessful collisions with t-BuNH2 before being transformed into product.
Stereoselectivity, Non-stereospecificity, and the Lifetime of the Thiometaphosphonimidate Intermediate formed in the Reactions of the Diastereoisomers of a Phosphonamidothioic Chloride with t-Butylamine
Harger, Martin J. P.
, p. 1256 - 1257 (2007/10/02)
Both diastereoisomers of t-BuP(S)(Cl)NHR react with t-BuNH2 (0.25 M) in an aprotic solvent to give the same mixture of the diastereoisomers of t-BuP(S)(NHt-Bu)NHR (no stereospecificity), but the diastereoisomer ratio of the product (stereoselectivity) increases from 57 : 43 (MeCN) to 80 : 20 (cyclohexane) as the polarity (ετ) of the solvent is reduced.
