Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of benzyl 2-pyridyl carbonate $mathbf{3}$ and $t$-butyl 2-pyridyl carbonate $mathbf{3}$ with a series of alicyclic secondary amines in MeCN at $25.0{pm}0.1^{circ}C$. Substrate $mathbf{4}$ is much less reactive than $mathbf{3}$ and the steric hindrance exerted by the bulky $t$-Bu group in $mathbf{4}$ has been attributed to its decreased reactivity. The Br${o}$nsted-type plots for the reactions of $mathbf{3}$ and $mathbf{4}$ are linear with ${eta}_{nuc}=0.57$ and 0.45, respectively. Thus, the reactions have been concluded to proceed through a concerted mechanism, although the current reactions were expected to proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate $T^{pm}$. It has been proposed that the rate of leaving-group expulsion is accelerated by the intramolecular H-bonding interaction in $T^{pm}$ and the "push" provided by the RO group through the resonance interaction. Thus, the enhanced nucleofugality forces the reactions to proceed through a concerted mechanism. The reactivity-selectivity principle (RSP) is not applicable to the current reaction systems, since the reaction of the less reactive $mathbf{4}$ results in a smaller ${eta}_{nuc}$ than that of the more reactive $mathbf{3}$. Steric hindrance exerted by the bulky $t$-Bu group in $mathbf{4}$ has been suggested to be responsible for the failure of the RSP.