R. Donoso et al., C-13 NMR CHEMICAL-SHIFTS OF ALKYL 3-HYDROXYTHIOPHENE-2-CARBOXYLATES AND 3-ALKYLAMINO-1-(3-THIENYLOXY)-2-PROPANOLOLS, Heterocyclic communications, 2(1), 1996, pp. 17-20
A compilation of C-13 NMR chemical shifts for 35 thiophene derivatives
of types Ia and Ib is reported. The data have been analyzed assuming
an additive model delta(n) = a(0) + Sigma a(i)x(i), where n is the thi
ophene carbon considered (n = 2-5) and al the contribution of each sub
stituent (x(i) = 1 if the substituent is present and x(i) = 0 if absen
t).