Kinetic studies on the reactions of Y-phenyl chloroformates with X-pyridines in acetonitrile are carried out at 25.0° C. Both the Hammett and Brönsted plots are linear with enhanced substituent constants, σp-, and basicities, p K a-, for strong para π-acceptor X-substituents, p- CN and p-CH3CO. This indicates that the electron-rich formate (OCO) moiety overlaps with the pyridine ring π-system enabling, through conjugation with the para π-acceptors, the ...
