Premium
15 N chemical shifts of a series of isatin oxime ethers and their corresponding nitrone isomers
Author(s) -
Liu Xiaohong,
Huang Xiaohua Stella,
Sin Ny,
Venables Brian L.,
Roongta Vikram
Publication year - 2010
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2680
Subject(s) - chemistry , nitrone , isatin , chemical shift , oxime , alkylation , carbon 13 nmr , proton nmr , organic chemistry , medicinal chemistry , cycloaddition , catalysis
In this article, we describe the characteristic 15 N chemical shifts of isatin oxime ethers and their isomer nitrone. These oxime ethers and nitrones are the alkylation reaction products of isatin oximes. In our study, the 15 N chemical shifts observed in these oxime ethers were in the 402–408 (or 22–28) ppm range, although those for their corresponding nitrone series were in the 280–320 (or −100 to −60) ppm range. This remarkable difference in 15 N NMR chemical shift values could potentially be used to determine the O ‐ versus N ‐alkylation of oximes, even when only one isomer is available. In this paper, the differences in 15 N NMR chemical shifts serve as the basis for a discussion about how to distinguish both regioisomers derived from the oximes alkylation. Copyright © 2010 John Wiley & Sons, Ltd.