Synthesis, Enantiomeric Conformations, and Stereodynamics of Aromatic ortho-Substituted Disulfones

✍ Scribed by Jérôme Lacour; David Monchaud; Jiri Mareda; France Favarger; Gérald Bernardinelli

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: German
• Weight: 346 KB
• Volume: 86
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200390020

✦ Synopsis

Abstract

Aromatic ortho‐disulfone derivatives are readily accessible from diiodide precursors by Cu^I^‐mediated reaction with sodium sulfinate salts (DMF, 110°). The sulfonyl substituents adopt in solution and in the solid state two enantiomeric conformations (λ and δ) as evidenced by ^31^P‐ and ^1^H‐NMR data of the chiral D~3~‐symmetric tris{4,5‐bis[(4‐methylphenyl)sulfonyl]benzene‐1,2‐diolato(2−)‐κO,κO′}phosphate(v) anion (3a) and 1,2‐bis(camphor‐10‐sulfonyl)‐4,5‐dimethoxybenzene ((=1,2‐bis{{[(1__S__,4__R__)‐7,7‐dimethyl‐2‐oxobicyclo[2.2.1]hept‐1‐yl]methyl}sulfonyl}‐4,5‐dimethoxybenzene; 6c). X‐Ray structure analysis of 1,2‐dimethoxy‐4,5‐bis(methylsulfonyl)benzene (6a) and 1,2‐dimethoxy‐4,5‐bis(4‐methylphenyl)sulfonyl]benzene (6b) confirmed in the solid state the preferred chiral orientation of the sulfonyl groups. Dynamic conformational isomerism was detected for 6c in its ^1^H‐NMR in the temperature range of 110°, the corresponding free energy being 19.8 kcal⋅mol^−1^.