Identify the correct decreasing order of nucleophilicity for the following substituted pyridines: (i) (ii) (iii)

Step-by-step solution

Nucleophilicity is the ability of a species to donate an electron pair to an electrophile. In substituted pyridines, the nitrogen atom acts as the nucleophilic center. While alkyl groups at the 2- and 6-positions exert an electron-donating inductive effect ( +I ) that increases electron density on the nitrogen atom, nucleophilicity is highly sensitive to steric hindrance because the nucleophile must approach a relatively bulky electrophilic center. In 2-methylpyridine (i), there is only one methyl group adjacent to