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α-Phenylethylamine-Based Chiral Phospholidines; New Agents for the Determination of the Enantiomeric Excess of Chiral Alcohols, Amines and Thiols by Means of 31P NMR
| Content Provider | Semantic Scholar |
|---|---|
| Author | Hulst, Ron Vries, Nanne K. De Feringa, Bernard |
| Copyright Year | 1994 |
| Abstract | The synthesis and application of two new trivalent phosphorus derivatizing agents, based upon (S)-α-phenylethylamine, for the enantiomeric excess determination of alcohols, amines and thiols using P NMR, is presented. The tremendous effort in asymmetric synthesis and the rapidly increasing use of enantiomerically pure compounds as chiral building blocks, auxiliaries or chiral ligands require the development of fast and accurate methodologies for the determination of the enantiomeric composition. The enantiomeric ratio of various classes of compounds can be determined by a number of analytical techniques, although chromatographic and NMR methods are routinely most frequently used. Despite the rapid progress that has been made in the development of resolution on GC and HPLC, NMR is an attractive technique as it is usually fast and relatively simple to perform. Moreover, NMR offers the possibility to measure various nuclei. The enantiomeric excess (e.e) determination by means of NMR can be performed using chiral lanthanide shift reagents, chiral complexing agents and through the use of chiral non-racemic derivatizing agents. Furthermore, efficient methods using achiral derivatizing agents, based upon Horeau’s principle, were developed in our laboratory for the determination of the enantiomeric excess of amines, alcohols and thiols. More recently, P NMR methods have become very popular due to the attractive features of this nucleus in the analysis of chiral compounds. Several derivatizing agents have been developed in our group, among which are trivalent and pentavalent achiral phosphorus reagents like PCl3 or MePOCl2 and chiral phosphoric acid chlorides or phosphorinane reagents. Trivalent phosphorus reagents based on 1,2-N,N’-(dimethylamino)-cyclohexane probably give the most pronounced diastereomeric shift dispersion in the decoupled P NMR spectra of their derivatives with chiral substrates, as was shown by Alexakis and co-workers. The lack of availability of the chiral cyclohexyl-based diamines and the sensitivity of the derivatizing reagents towards hydrolysis and oxidation in practice, urged us to |
| File Format | PDF HTM / HTML |
| DOI | 10.1002/chin.199434052 |
| Volume Number | 25 |
| Alternate Webpage(s) | https://www.rug.nl/research/portal/files/3294368/1994TetrahedronAsymHulst1.PDF |
| Alternate Webpage(s) | https://doi.org/10.1002/chin.199434052 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
