Thermodynamically stabilized chiral chalcogen oxides: optical resolution and stereochemistry

✍ Scribed by Hideo Taka; Akikuni Matsumoto; Toshio Shimizu; Nobumasa Kamigata

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 159 KB
• Volume: 12
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.1037

✦ Synopsis

Abstract

Optical resolution of racemic selenoxides, 1a, 1b, and 1c, and telluroxide 2b, possessing an 8‐dimethylamino‐1‐naphthyl group by liquid chromatography using optically active columns afforded the corresponding enantiomerically pure stereoisomers. Absolute configurations of the optically active chalcogen oxides were assigned by comparison of their specific rotations and CD spectra with those of the sulfur analog. All of the optically active chalcogen oxides obtained were stable toward racemization in their solid states; however, selenoxides 1a and 1b and telluroxide 2b racemized in solutions. Kinetic studies of the racemization clarified that thermodynamic stabilization by intramolecular coordination of the nitrogen atom in the 8‐dimethylamino‐1‐naphthyl group to the chalcogen atom was effective to prevent the racemization. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:227–237, 2001