The properties of enamines depend on slight changes in reaction conditions
or structural factors. From the analysis of the data which is available in
the literature, B3LYP/6-311 +G(3df,3pd)//MP2/6-31+G** calculations and usin
g the Taft and Topsom model of the intrinsic substituent effect in the basi
city, we found a resonance effect that explains why vinylamine and N,N-dime
thylvinylamine are both carbon and not nitrogen bases (the resonance factor
for vinylamine increases carbon basicity by about 56 kcal/mol). (C) 2001 E
lsevier Science B.V. All rights reserved.