Acide 2-fluoro-2-phényl propanoïque: préparation et utilisation comme agent chiral de dérivation
摘要:
The enantiomers of 2-fluoro-2-phenyl propanoic acid have been separated and their absolute configurations determined: the specific rotation of the acid with an R configuration is [alpha]20D, =-28.5-degrees (c=1.5, ethanol). This acid has been used as a chiral derivatizing agent. Esters and amides prepared from this acid and chiral alcohols or amines present important fluorine chemical shift differences between the diastereoisomers.
Acide 2-fluoro-2-phényl propanoïque: préparation et utilisation comme agent chiral de dérivation
摘要:
The enantiomers of 2-fluoro-2-phenyl propanoic acid have been separated and their absolute configurations determined: the specific rotation of the acid with an R configuration is [alpha]20D, =-28.5-degrees (c=1.5, ethanol). This acid has been used as a chiral derivatizing agent. Esters and amides prepared from this acid and chiral alcohols or amines present important fluorine chemical shift differences between the diastereoisomers.
Stereospecific Synthesis of<i>sec</i>- and<i>tert</i>-Alkyl Azides from Alcohols and Trimethylsilyl Azide by a New Type of Oxidation–Reduction Condensation Using Phenyl Diphenylphosphinite and Trimethylsilylmethyl Azide
A novel method for the preparation of alkyl azides from alcohols and trimethylsilyl azide by a new type of oxidation–reduction condensation using phenyl diphenylphosphinite and trimethylsilylmethyl azide is described. Chiral secondary and tertiary alcohols are converted into the corresponding chiral azides with almost complete inversion of configuration under mild and neutral conditions.
Conversion of tertiary alcohols to tert-alkyl azides by way of quinone-mediated oxidation–reduction condensation using alkyl diphenylphosphinites
作者:Kiichi Kuroda、Yujiro Hayashi、Teruaki Mukaiyama
DOI:10.1016/j.tet.2007.03.176
日期:2007.7
A novel method for the preparation of alkyl azides from alcohols by way of oxidation–reduction condensation is described. In this reaction, the sterically-hindered tert-alkyl phosphinites that are prepared from the corresponding alcohols are converted into tert-alkyl azides with almost complete inversion of their stereochemistry: the obtained alkyl azides are then successfully reduced to afford the
A novel method for the preparation of alkyl azides from alcohols by way of oxidation-reduction condensation is described. According to this reaction, the sterically hindered tert-alkyl phosphinites that are prepared from the corresponding alcohols are converted into tert-alkyl azides with almost complete inversions of their stereochemistries. On treatment with LiAlH 4 the obtained alkyl azides are