Identify the correct decreasing order of nucleophilicity for the following compounds: (I) (II) (III)

Step-by-step solution

The nucleophilicity of pyridine derivatives depends on the availability of the lone pair of electrons on the nitrogen atom. Electron-donating groups (EDG) increase the electron density on the nitrogen atom, thereby increasing nucleophilicity. Conversely, electron-withdrawing groups (EWG) decrease the electron density on the nitrogen atom, decreasing nucleophilicity. In compound (I), the - CH ₃ group acts as an EDG through +I and hyperconjugation effects, making it the strongest nucleophile among the given compounds