154775-46-9Relevant academic research and scientific papers
Base Induced Rearrangement on an α-Bromophosphonamidate: Stereochemistry of Ring Opening of the Azaphosphiridine Oxide Intermediate as revealed by X-Ray Crystallography
Fawcett, John,Harger, Martin J. P.,Russell, David R.,Sreedharan-Menon, Ramesh
, p. 1826 - 1828 (1993)
Methoxide-induced rearrangement of the α-bromophosphonamidate 1b (X=Br) gives two products, 2b and 3b, corresponding to breakdown of the intermediate azaphosphiridine oxide 4b by nucleophilic attack at phosphorus, and cleavage of the P-N bond (major pathway) with inversion of configuration or the P-C bond (minor pathway) with retention; this suggests involvement of a five-coordinate species as an intermediate, not merely as a transition state.
Stereochemistry of the methoxide induced rearrangement of an α-bromophosphonamidate: Cleavage of the P-N and P-C bonds in the azaphosphiridine oxide intermediate
Harger, Martin J. P.,Sreedharan-Menon, Ramesh
, p. 527 - 532 (2007/10/03)
Menthyl P-(bromomethyl)-N-tert-butylphosphonamidate 5 has been prepared from (1R,2S,5R)-(-)-menthol and the SP diastereoisomer has been isolated. This rearranges with methoxide [Me3(PhCH2)N+ MeO- in THF-MeOH] to give only the SP diastereoisomer of menthyl methyl (tert-butylamino)-methylphosphonate 6 and very largely (95%) the SP diastereoisomer of menthyl methyl N-tert-butyl-N-methylphosphoramidate 7. The configurations of these products show that when the (postulated) azaphosphiridine oxide intermediate 16 suffers ring opening by methoxide, the P-N bond is cleaved (to give 6) with inversion of configuration but the P-C bond is cleaved (to give 7) with predominant retention. These contrasting stereochemistries suggest that nucleophilic attack on the P=O group of the azaphosphiridine oxide generates a five-coordinate intermediate (not merely a transition state) that exists long enough to undergo pseudorotation.
