Final answer:
Electron-donating groups near the carbonyl carbon increase the electron density at this carbon atom, making it more nucleophilic and enhancing its reactivity towards electrophiles.
Step-by-step explanation:
Electron-donating groups near the carbonyl carbon have a significant effect on the reactivity of compounds that contain this functional group. These electron-donating groups, such as hydroxyl (-OH), amino (-NH2), and alkoxyl (-OR) groups, increase the electron density near the carbonyl carbon. This increased electron density makes the carbonyl carbon more nucleophilic and facilitates its attack on electrophiles.
For example, in the case of aldehydes and ketones, electron-donating groups can enhance the nucleophilic addition reactions by increasing the electron density at the carbonyl carbon, thereby making it more susceptible to attack by nucleophiles. The resonance effect should also be considered when discussing the effect of electron-donating groups on the carbonyl carbon's reactivity.
In summary, electron-donating groups near the carbonyl carbon increase the electron density at this carbon atom, making it more nucleophilic and enhancing its reactivity towards electrophiles.