Question

Explain why alkylation increases the nucleophilicity of the ring when we synthesize 1 ,4-di-tert-butyl-2 5-dimethoxybenzene

OCH ОСНз C(CH3)3 2(CH,),COH 50 CH3 OCH In this reaction, the electrophile is a carbocation, generated by treating a tertiary alcohol ((CH3),C-OH) with á Strong acid CHoSO) as the dehydrating agent The advantage of this method for generating the electrophile is that the tertiary butyl cation is a stable carbocation and does not rearrange CH3 CH H3 After the electrophilic cation has been formed, it will attack the benzene ring (see nechanism above). Also note that in this reaction our ring is dialkylated./Polyalkylation ccurs because (alkylation increases the nucleophilicity of the ring, increasing the eactivity of the system However, alkylation does not proceed beyond dialkylation, in his case., because the two remaining positions on the ring are too sterically hindered for

Answer 1

Because Alkyl Groups Are Electron Releasing Groups And the tertiary alkyl groups are the most electron releasing.

So when they are attached to the ring, They increase the electron density on the Ring and Hence increase the nucleophilicity of the Ring.