Some new protocols for the assignment of absolute configuration by NMR spectroscopy using chiral solvating agents and CDAs

Mishra, Sandeep Kumar and Suryaprakash, Nagarajarao (2017) Some new protocols for the assignment of absolute configuration by NMR spectroscopy using chiral solvating agents and CDAs. In: TETRAHEDRON-ASYMMETRY, 28 (10, SI). pp. 1220-1232.

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Abstract

The utility of enantiopure BINOL (1,10-Bi-2-naphthol), in a ternary ion-pair complex, which is obtained using a carboxylic acid and an organic base, as a versatile chiral solvating agent (CSA) has been demonstrated for chiral analysis and the absolute configuration assignment of hydroxy acids. Another protocol where the utility of NOBIN as a CSA has been developed for discrimination and absolute configuration assignment of acids, hydroxy acids and their derivatives with a distinct strategy where a third ingredient, p-toluenesulfonic acid (p-TsOH) serves as a linker. In addition some three component chiral derivatization protocols have been introduced, such as the use of 2-formylphenylboronic acid and enantiopure mandelic acid or a primary amine for the determination of the configuration of primary amines and hydroxy acids, respectively. A simple, rapid and highly efficient three component chiral derivatizing protocol has also been discussed which was developed for assigning the absolute configuration of chiral alpha-hydroxy acids and their derivatives, which involves the coupling of 2-formylphenylboronic acid with (R)-1,1-binaphthalene]-2,2-diamine, and (S)1,1-binaphthalene1-2,2-diamine separately. In a few examples, the DFT based theoretical calculations have been carried out to determine the geometry optimized structures of the complexes. (C) 2017 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	TETRAHEDRON-ASYMMETRY
Additional Information:	Copy right for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	23 Dec 2017 08:30
Last Modified:	23 Dec 2017 08:30
URI:	http://eprints.iisc.ac.in/id/eprint/58526

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