How do heteroatoms create reactive sites in organic compounds?

Heteroatoms create reactive sites in organic compounds primarily by introducing polar bonds through their interaction with carbon.12

In organic molecules, carbon-to-carbon and carbon-to-hydrogen bonds are generally strong and exhibit an even distribution of electron density, making them relatively unreactive. Reactivity increases significantly when a heteroatom—any atom other than carbon or hydrogen—is bonded to carbon. Because heteroatoms possess different electron-attracting properties (electronegativity) than carbon, they cause an unequal sharing of the bonding electron pair.12

This unequal distribution results in a polar bond where the more electronegative atom develops a partial negative charge and the other atom develops a partial positive charge. These regions of increased or decreased electron density are critical for chemical change because they create sites that can attract electron-deficient or electron-rich species, thereby initiating the bond-breaking processes necessary for chemical reactions. Consequently, these polar bonds often serve as the foundation for functional groups, which are the specific sites where a molecule's reactivity is concentrated.12