A New Method for Distinguishing between Enantiomers and Racemates and Assignment of Enantiomeric Purity by Means of Solid-State NMR. Examples from Oxazaphosphorinanes

Potrzebowski, Marek J.; Tadeusiak, Elżbieta; Misiura, Konrad; Ciesielski, W.; Bujacz, G.; Tékély, Piotr

doi:10.1002/1521-3765(20021104)8:21<5007::aid-chem5007>3.0.co;2-b

Cited by 16 publications

(11 citation statements)

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“…The preliminary results, which clearly proved that it is possible to distinguish enantiomer from racemate prompted by Potrzebowski et al (30) for testing of the 31 P ODESSA experiment as the method for establishing of enantiomeric excess for P-chiral compounds. In cited work, authors studied the enantiomeric purity of the oxazaphosphorine derivatives (cyclophosphamides 8-10) shown in Scheme 3, which are used in oncology as a therapeutic agent.…”

Section: Discrimination Of Enantiomers and Racemates By Means Of One-mentioning

confidence: 89%

NMR studies of chiral organic compounds in non‐isotropic phases

Potrzebowski¹,

Jeziorna²,

Kaźmierski³

2008

Concepts Magnetic Resonance

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In this article, new applications and perspectives of one-and two-dimensional NMR spectroscopy for study of chiral organic compounds in the non-isotropic phases (solid state and liquid crystals) are presented. The review is organized into five sections. In the first part, theoretical background and short introduction to solid state NMR are shown. The second part presents how NMR isotropic chemical shift can be used for distinguishing of racemates and enantiomers. In the third section, the power of the ODESSA pulse sequence for investigation of racemates, enantiomers and establishing of enantiomeric excess are discussed. The fourth part shows the application of analysis of principal elements of chemical shift tensors obtained by means of 2D NMR techniques for searching of absolute configuration and conformational changes in the solid state. The final part presents recent achievements of chiral liquid crystals NMR methodology for study of chiral compounds.

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Section: Discrimination Of Enantiomers and Racemates By Means Of One-mentioning

confidence: 89%

NMR studies of chiral organic compounds in non‐isotropic phases

Potrzebowski¹,

Jeziorna²,

Kaźmierski³

2008

Concepts Magnetic Resonance

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“…Figure 12 shows how sensitive W ij values are to differences in intermolecular P ··· P distances and how easy it is to distinguish an enantiomer from the racemate by employment of the ODESSA pulse sequence technique. It was also shown that, under favorable circumstances, it is possible to establish enantiomeric excesses of mixtures of stereoisomers by employing the ODESSA approach 68. It is worth noting that the observation is not unique and that this approach can be extended to other systems 67…”

Section: High‐resolution Solid‐state Nmr Spectroscopy As a Tool Wimentioning

confidence: 94%

“…Tekely and co‐workers have recently proposed an NMR method based on One‐Dimensional Exchange Spectroscopy by Sideband Alternation (ODESSA),66 which allows enantiomers and racemates to be distinguished 67. The power of the proposed approach was demonstrated by employing P‐chiral oxazaphosphorine derivatives, widely used in clinical oncology, as model compounds (Scheme ) 68…”

Section: High‐resolution Solid‐state Nmr Spectroscopy As a Tool Wimentioning

confidence: 99%

What High‐Resolution Solid‐State NMR Spectroscopy Can Offer to Organic Chemists

Potrzebowski

2003

Eur J Org Chem

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New applications of one‐ and two‐dimensional solid‐state NMR spectroscopy in structural studies of organic solids are presented. The review is organized into sections, the first part presenting recent progress in investigation of polymorphism and pseudo‐polymorphism phenomena. New advances in solid‐state NMR in studies of strong and weak hydrogen bonding are described in the second section, while the final part presents NMR spectroscopy as a tool with which to distinguish between enantiomers and racemates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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“…Figure 12 shows how sensitive W ij values are to differences in intermolecular P···P distances and how easy it is to distinguish an enantiomer from the racemate by employment of the ODESSA pulse sequence technique. [68] It is worth noting that the observation is not unique and that this approach can be extended to other systems. [68] It is worth noting that the observation is not unique and that this approach can be extended to other systems.…”

Section: High-resolution Solid-state Nmr Spectroscopy As a Tool With mentioning

confidence: 96%

“…[67] The power of the proposed approach was demonstrated by employing P-chiral oxazaphosphorine derivatives, widely used in clinical oncology, as model compounds (Scheme 4). [68] Scheme 4 By employing the well-known fact that the molecular symmetries and packings of enantiomers and racemates are usually significantly different and that the intermolecular distances between chemically equivalent nuclei differ accordingly, it was assumed that the rate constants W ij of spin diffusion obtained from the intensities of spinning sidebands as a function of mixing time should also be dissimilar. Figure 12 shows how sensitive W ij values are to differences in intermolecular P···P distances and how easy it is to distinguish an enantiomer from the racemate by employment of the ODESSA pulse sequence technique.…”

Section: High-resolution Solid-state Nmr Spectroscopy As a Tool With mentioning

confidence: 99%