Organic reaction mechanism bond cleavage types

The latter reagent allowed the substitution on some poorly activated substrates, such as 0- and w-dichlorobenzene, to give, although in moderate yields, o- and m-chloroanisole, respectively. This shows that the reaction involves direct attack of the nucleophile at the reaction center, not a benzyne-type mechanism These intermediates cannot be detected in liquid-liquid PTC where the water associated to the anion in the organic phase assists the cleavage of the bond between the leaving-group and the aromatic carbon atom... 

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