Chiral anisotropy reagent

MaNP ACID, A CHIRAL HNMR ANISOTROPY REAGENT (CAR) USEFUL FOR BOTH ENANTIORESOLUTION OF ALCOHOLS AND SIMULTANEOUS DETERMINATION OF THEIR ACs BY H NMR DIAMAGNETIC ANISOTROPY... 

Naito J, Taji H, Sekiguchi S, Watanabe M, Kuwahara S, Watanabe M, Harada N. A new route to enantiopure MaNP acid, a powerful resolution and chiral H NMR anisotropy reagent. 

Nevertheless, it is possible to convert a racemic sample with chiral reagents into diastereomers or simply to dissolve it in an enantiomericaUy pure solvent R or S following this process, solvation diasteromers arise from the racemate (RP + SP) of the sample P, e.g. R RP and R SP, in which the enantiomers are recognisable because of their different shifts. Compounds with groups which influence the chemical shift because of their anisotropy effect (see Sections 2.5.1 and 2.5.2) are suitable for use as chiral solvents, e.g. 1-phenylethylamine and 2,2,2-trifluoro-l-phenylelhanol. ... 

In our studies, we have always employed only MaNP acid (S)-(- -)-3 as a CAR, and not the other enantiomer (R)-(—)-3. The reason why we have used only (5)-(- -)-3 is to prevent a careless mistake in determination of AC. If the AC of a CAR is mistaken, the results obtained by H NMR anisotropy are wrong. So, researchers should always mind which enantiomer of chiral reagents is used in their experiments. Chiral (15,2R,4R)-( )-CSDP, (R)-(-)-MaNP, and (S)-(+)-MaNP acids are commercially available from TCI (http //www.tciamerica.com/ or http //www.tcieurope.eu/). 

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