
TY  - JOUR
A1  - Rottendorf, H 
A1  - Sternhell, S 
T1  - Spin-spin coupling between side-chain and ring protons and the effect of electron delocalization on allylic coupling
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1964
VL  - 17
IS  - 12
SP  - 1315
EP  - 1328
KW  - 
UR  - https://doi.org/10.1071/CH9641315 
N2  - The side-chain-ring coupling constants3 in the three isomeric tetrachlorotoluenes are Jortho 0.63±0.02 c/s, Jmeta 0.36±0.02 c/s, and Jpara 0.63±0.01 c/s. The magnitudes of side-chain coupling constants in benzene derivatives are discussed. In symmetrical six-membered aromatic and heterocyclic compounds the magnitude of the ortho side-chain coupling constants is approximately 0.6 c/s but varies from less than 0.3 cis to 1.1 c/s in molecules where some bond localization occurs. Ortho side-chain coupling constants in five-membered heterocyclic compounds also appear to be affected by electron localization. It is therefore likely that the magnitude of the ortho side-chain coupling constants may be a direct measure of bond order. Long-range coupling data on indole derivatives are reported. In two &#946;,&#946;-dimethylstyrenes the stronger side-chain to ring coupling is to the ortho position. The relation between allylic coupling and electron delocalization is explored and a new criterion for electron delocalization proposed. 
ER  -

