Concerted pyridinolysis of aryl 2,4,6-trinitrophenyl carbonates.
The Brønsted plots for the title reactions are linear with slopes of 0.53-0.56. The magnitude of the slopes and the fact that there are no breaks at the predicted pK(a) for stepwise mechanisms indicate that these reactions are concerted. This finding is in great contrast to the stepwise mechanisms found for the pyridinolysis of other carbonates. The concerted mechanism is attributed to the fact that the title carbonates possess two O-aryl groups, one of them being an exceptionally good nucleofuge.
Castro
Enrique A
EA
Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 6094411, Chile. ecastro@uc.cl
Ramos
Mariela
M
Santos
José G
JG