Premium
Stereoelectronic Effects in Cyclic Sulfoxides, Sulfones, and Sulfilimines: Application of the Perlin Effect to Conformational Analysis
Author(s) -
Wedel Tobias,
Müller Monika,
Podlech Joachim,
Goesmann Helmut,
Feldmann Claus
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601468
Subject(s) - chemistry , sulfoxide , coupling constant , alkane stereochemistry , stereochemistry , heteronuclear single quantum coherence spectroscopy , crystallography , computational chemistry , medicinal chemistry , nuclear magnetic resonance spectroscopy , organic chemistry , crystal structure , physics , particle physics
The 1 J CH coupling constants in conformationally constrained sulfoxides, bissulfoxides, sulfoxide‐sulfones, and sulfilimines derived from 2‐benzylidene‐1,3‐dithiane and 2‐(2,2‐dimethylpropylidene)‐1,3‐dithiolane were measured by means of HMQC and HSQC NMR experiments and the Perlin effects were calculated. The type and the relative configuration of SX groups (X= O, NTos) in these compounds have a strong influence on the magnitude of coupling constants for axial and equatorial CH bonds, respectively. Axial SO bonds give rise to a stereoelectronic effect on antiperiplanar axial CH bonds. The resultant weakening of the respective CH bonds leads to a smaller coupling constant than for a respective equatorial CH bond. Equatorial SO groups have an influence on β‐CH bonds through a homoanomeric effect. Here, the axial CH bond is weakened and a smaller coupling constant is measured. Sulfilimine groups show similar effects to sulfoxide groups.