102493-38-9Relevant academic research and scientific papers
Endocyclic restriction test: Applications to transfers of oxygen from nitrogen and from sulfur to phosphorus(III)
Kurtzweil, Mitchell L.,Beak, Peter
, p. 3426 - 3434 (2007/10/03)
The geometries allowed for formal transfers of oxygen to the phosphorus(III) of a phosphine from a nitrone, an O-acetylhydroxylamine, and a sulfoxide have been evaluated by the endocyclic restriction test. Investigations of the conversions of 1 to 2, 16 to 17, and 28 to 29, by isotopic labeling, substituent effect, and kinetic and spectroscopic experiments, reveal the operation of different mechanisms for each of these transfers. For 1, oxygen addition to phosphorus is the preferred mechanism. In the case of 16, the mechanism involves nucleophilic displacement of oxygen from nitrogen by phosphorus to give 26 followed by oxygen addition to phosphorus. In acetic acid, the oxygen is added to 26 from water in the workup whereas in toluene the oxygen is provided by the acetate produced by the displacement. For 28, either addition by oxygen of the sulfoxide to activated phosphorus or addition by phosphorus to sulfur of the sulfoxide precedes oxygen transfer.
The endocyclic restriction test: Determination of the transition-structure geometry for the transfer of oxygen from N,N-dialkylhydroxylamines to triarylphosphines
Kurtzweil, Mitchell L.,Loo, Dekai,Beak, Peter
, p. 421 - 427 (2007/10/02)
The transfers of oxygen from nitrogen to phosphorus in the conversions of 1 to 2 and 3 to 4 are shown by kinetic, solvent-labeling, and double-labeling criteria to be intramolecular reactions. This information in conjunction with the stabilities of 13 and 14 is taken to rule out the mechanisms of classic linear SN2 substitutions at oxygen or nitrogen, biphilic insertion, or a radical chain reaction and to favor reactions via a 10-P-5 species (18). These results appear to provide the first experimental demonstration that oxygen can be transferred at an oblique angle.
