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Synthesis, Enantiomeric Conformations, and Stereodynamics of Aromatic ortho ‐Substituted Disulfones
Author(s) -
Lacour Jérôme,
Monchaud David,
Mareda Jiri,
Favarger France,
Bernardinelli Gérald
Publication year - 2003
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200390020
Subject(s) - chemistry , sulfonyl , enantiomer , benzene , medicinal chemistry , nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , alkyl
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 .