Final Answer:
The most contributing resonance structure of the Wheland intermediate generated in the reaction shown below is the one where the positive charge is delocalized onto the benzene ring, forming a stabilized arenium ion.
Step-by-step explanation:
In the given reaction, the Wheland intermediate is formed by the attack of an electrophile on the benzene ring. The most contributing resonance structure of this intermediate can be determined by examining the stability of the resulting structures.
The resonance structure where the positive charge is delocalized onto the benzene ring is the most stable due to the aromatic stabilization provided by the delocalization of pi electrons. This results in a stabilized arenium ion, making it the most contributing resonance structure.
The delocalization of the positive charge onto the benzene ring can be represented using curved arrows to show the movement of electrons. This delocalization leads to a more stable intermediate, as compared to other resonance structures where the positive charge is localized on a single carbon atom.
Therefore, in this reaction, the most contributing resonance structure of the Wheland intermediate is the one where the positive charge is delocalized onto the benzene ring.
Understanding and identifying the most contributing resonance structure is crucial in organic chemistry as it provides insights into reaction mechanisms and helps predict reactivity and selectivity in various organic transformations.