Give benzene mechanism for nucleophilic aromatic subsitution of aryl halide.
What are
evidences in support of this mechanism
Answers
Explanation:
aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. There are 6 nucleophilic substitution mechanisms encountered with aromatic systems:
the SNAr (addition-elimination) mechanism
SNAr mechanism
the aromatic SN1 mechanism encountered with diazonium salts
Aromatic SN1mechanism
the benzyne mechanism (E1cb-AdN)
Substitution via benzyne
the free radical SRN1 mechanism
the ANRORC mechanism
Vicarious nucleophilic substitution.
The most important of these is the SNAr mechanism, where electron withdrawing groups activate the ring towards nucleophilic attack, for example if there are nitro functional groups positioned ortho or para to the halide leaving group.