Interpretation:
Given that phenylboronic acid upon nitration gives 15% orthosubstitution product and 85% meta product. The meta directing effect of the –B(OH)2 group is to be explained.
Concept introduction:
The substituents attached to the ring have a strong influence on the incoming electrophile. Electron releasing substituent groups, except halogens, activate the ring and direct the incoming electrophile to the o- and p- positions. Halogens are o- and p- directors but they deactivate the ring. Electron withdrawing substituent groups deactivate the ring and direct the incoming electrophile to the m- position. Boron compounds are usually electron acceptors as in these compounds boron is electron deficient.
To explain:
The meta directing effect of the –B(OH)2 group as upon nitrating phenylboronic acid 15% orthosubstitution product and 85% meta product are obtained.
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Chapter 16 Solutions
Organic Chemistry
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