- N-(Alkylphenylphosphinoyl)hydroxylamines: Highly Selective Migration of the Phenyl Group in the Base-induced Rearrangement of their O-Methylsulphonyl Derivatives
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The N-(alkylphenylphosphinoyl)hydroxylamines RPh(O)NHOH (R=Me, Et, or Pri) have been prepared and converted into their O-methylsulphonyl derivatives RPhP(O)NHOMs.These readily rearrange on treatment with methylamine, t-butylamine, or sodium methoxide-methanol to give only the products RP(O)(NHPh)X (X=NHMe, NHBut, or OMe) resulting from migration of the phenyl group.The rates of reaction are essentially the same when R=Me and R=Pri, indicating that the rearrangement is not brought about by nucleophilic attack at phosphorus.A likely mechanism involves base-induced rearrangement to a monomeric metaphosphonimidate which then reacts rapidly with the nucleophile.
- Harger, Martin J. P.,Smith, Adrian
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p. 683 - 688
(2007/10/02)
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- Direct Deoxygenation of the Hydroxy Group of Methyl 1-Hydroxyalkyl-(phenyl)-phosphinates using Diphosphorus Tetraiodide
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The hydroxy group of methyl 1-hydroxyalkyl-(phenyl)-phosphinates 3, prepared from methyl phenylphosphinate 1 and aldehydes or ketones 2, is directly deoxygenated on treatment with diphosphorus tetraiodide to give the methyl alkyl-(phenyl)-phosphinates 4.
- Yamashita, Mitsuji,Tsunekawa, Kenji,Sugiura, Motoyuki,Oshikawa, Tatsuo,Inokawa, Saburo
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p. 896 - 897
(2007/10/02)
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- Base-induced Rearrangement of the O-Methanesulphonyl Derivatives of N-(Alkylphenylphosphinoyl)hydroxylamines. Highly Selective Migration of the Phenyl Group
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The N-(alkylphenylphosphinoyl)-O-methanesulphonylhydroxylamines RPhP(O)NHOSO2Me (R = Me, Et, or Pri) react readily with MeNH2 or NaOMe-MeOH to give products resulting from phenyl, but not alkyl, migration.
- Harger, Martin J. P.,Smith, Adrian
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p. 1140 - 1141
(2007/10/02)
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- PHOTOLYSIS OF SOME UNSYMMETRICAL PHOSPHINIC AZIDES IN METHANOL. RELATIVE MIGRATORY APTITUDES OF ALKYL GROUPS AND PHENYL IN THE CURTIUS-LIKE REARRANGEMENT.
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When an alkylphenylphosphinic azide RPhP(O)N3 (R=Me, Et, Pri or But) is photolysed in MeOH either the alkyl or phenyl group can migrate from P to N in the Curtius-like rearrangement.The composition of the product shows that migration of the alkyl group R is preferred.However, the preference is not great and decreases as R changes But->Pri->Et->Me-> (approx. migratory aptitudes relative to Ph: 2.1, 1.7, 1.3, 1.2 respectively), probably because the Ph-P bond is better able to assume the correct conformation for Ph migration when R is less bulky.For t-butylmethylphosphinic azide there is very little preference for migration of But relative to Me.Small amounts of unrearranged products such as ButPhP(O)NHOMe and ButPhP(O)NH2 are generally produced in the photolyses, together with the methyl phosphinates RPhP(O)OMe (major product when R=Me) resulting from (non-photochemical) solvolysis of the azide.
- Harger, Martin J. P.,Westlake, Sally
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p. 3073 - 3078
(2007/10/02)
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- The Proton Magnetic Resonance Spectra of Chiral Phosphinate Esters. Chemical Shift Non-equivalence of Enantiomers induced by Optically Active Phosphinothioic Acids
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The 1H n.m.r. spectrum of racemic methyl methylphenylphosphinate recorded in CCl4 solution in the presence of 1 mol. equiv. of (+)-(R)-phenyl-t-butylphosphinothioic acid or (-)-(S)-methylphenylphosphinothioic acid contains well separated P-m
- Harger, Martin J. P.
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p. 1505 - 1511
(2007/10/02)
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