
TY  - JOUR
A1  - Yamagami, C 
A1  - Takao, N 
A1  - Takeuchi, Y 
T1  - Effects of Substituents on the Barriers to Rotation in Phenyl and Benzyl Carbamates
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1986
VL  - 39
IS  - 3
SP  - 457
EP  - 463
KW  - 
UR  - https://doi.org/10.1071/CH9860457 
N2  - The free energy of activation for rotation about the C-N bond (&#916;G&#8225;Tc) in substituted phenyl and benzyl N,N- dimethylcarbamates was determined by the 13C dynamic n.m.r. method. The &#916;G&#8225;Tc value depended linearly on Hammett's &#963; with positive p. We have separated the substituent effects into inductive and resonance effects by using dual substituent parameter ( d.s.p .) analysis, and found that the resonance effect is more important than the inductive effect for para derivatives, and vice versa for meta derivatives. General trends of electronic substituent effects on barriers to rotation in carbamates and structurally related amides are also discussed. The ortho steric effect was small. 
ER  -

