- A simple resolution procedure using the Staudinger reaction for the preparation of P-stereogenic phosphine oxides
-
The resolution of a variety of (±)-P-stereogenic phosphines is achieved by exploiting the Staudinger reaction of a (±)-phosphine with enantiopure (1S,2R)-O-(tert-butyldimethylsilyl)isobornyl-10-sulfonyl azide. The resulting mixtures of diastereomeric phosphinimines are generally separable by fractional crystallization or flash chromatography. Subsequent acid-catalyzed hydrolysis provides the corresponding optically pure phosphine oxides in high yields.
- Andersen,Ramsden,Che,Parvez,Keay
-
p. 7478 - 7486
(2007/10/03)
-
- Regio- and Stereo-selectivity in the Hydrogenation of Aryl Phosphines by Niobium Aryloxide Compounds
-
The sequential hydrogenation of the three aryl rings in PPh3 by the catalyst system /3BunLi occurs with relative rates of 39:28:1; NMR analysis of the PhPCy2 obtained from and shows a predominantly all cis hydrogenation of both aryl rings has occurred.
- Potyen, Mark C.,Rothwell, Ian P.
-
p. 849 - 852
(2007/10/02)
-
- Preparation of Alkylmethylphenylphosphines by the Method of Hewertson and Watson
-
The reaction of C6H5(CH3)PNa with some alkyl halides in liquid ammonia was studied.The resulting phosphines were characterized by elemental analyses, NMR spectra, and by the reaction with trimethylsilyl azide giving trimethylsilylimino triorganophosphoranes. - Keywords: Alkylmethylphenylphosphines, N-Trimethylsilylimino Triorganophosphoranes, NMR Spectra
- Wolfsberger, Werner
-
p. 295 - 298
(2007/10/02)
-
- Preparation and (31)P nuclear magnetic resonance studies of chiral phosphines
-
The reaction of Li metal with alkyldiphenylphosphines generates the alkylphenylphosphide anions, which can undergo subsequent reactions with alkyl halides to give chiral phosphines (RR'R''P).The (31)P nmr chemical shifts have been measured for these phosphines, and show greater deviations from the values predicted by the first order additivity model than do those of more symmetrical phosphines (i.e., R3P and R2R'P).The shifts for these chiral molecules, and for a wide range of other phosphines, can be accurately predicted using a second order pairwise additivity scheme.The dependence of the observed and calculated chemical shifts upon electronegativity and steric factors is discussed.
- Payne, Nicholas C.,Stephan, Douglas W.
-
-