What role do dipoles play in electrophilic addition reactions?

In electrophilic addition reactions, dipoles are critical as they help initiate the reaction with alkenes. Alkenes contain carbon-carbon double bonds, which are regions of high electron density. When a polar molecule approaches an alkene, the dipole of the polar molecule interacts with the electron-rich double bond. This interaction often leads to the formation of a positive site on one of the alkene’s carbons, making it more susceptible to attack by the electrophile (the positively charged part of the incoming polar molecule).

This process is essential for the electrophilic addition to occur because the alkene must first be activated by the electrophile, which is facilitated by the presence of the dipole. As a result, the reaction can proceed, leading to the formation of more stable carbocations, which are pivotal intermediates in these types of reactions.

The other concepts mentioned in the choices—like hydrogenation, stabilization of the double bond, and enhancement of boiling points—do not correctly describe the primary role of dipoles in the context of initiating electrophilic addition reactions.