Slow interconversion of enantiomeric conformers or atropisomers of anilide and urea derivatives of 2-substituted anilines.
N-Acylated 2-substituted anilines undergo slow Ar-N bond rotation, allowing in some cases isolation of enantiomeric or diastereoisomeric atropisomers and in others the determination of the rate of Ar-N bond rotation by NMR. 2-Iodoanilides bearing a branched N-substituent demonstrate sufficient enantiomeric stability to be resolvable, either by HPLC or by formation of diastereoisomeric lactanilide derivatives. For the first time, the rates of Ar-N rotation in 2-substituted N,N'-diarylureas have been established: they mainly fall in the region of 50-70 kJ mol(-1) with a relatively weak dependence on substituent size.
Adler
Thomas
T
School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Bonjoch
Josep
J
Clayden
Jonathan
J
Font-Bardía
Mercè
M
Pickworth
Mark
M
Solans
Xavier
X
Solé
Daniel
D
Vallverdú
Lluís
L
D000813:Anilides / Q000737:chemistry*; D000814:Aniline Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D014508:Urea / Q000031:analogs & derivatives / Q000737:chemistry*
D000813:Anilides; D000814:Aniline Compounds; D014508:Urea