Neighboring group effects reaction rate

The preparation of polyacrylamides and postpolymeri2ation reactions on polyacrylamides are usually conducted ia water. Reactions on the amide groups of polyacrylamides are often more compHcated than reactions of simple amides because of neighboring group effects. Reaction rates, for example, can differ considerably. 

Tin Chemistry Fundamentals, Frontiers and Applications Table 6.2.7 Effect of neighboring groups on reaction rate ... 

The metal, in acting as a collection point to bring reactants together, is likely at the very least to promote enhanced rates of reaction by operation of the neighboring group effect. If, in addition, the transmission of electronic effects of the metal (Secs. 6.2-6.5) also occurs, as is usually the case, then large overall rate enhancements may be encountered. 

On occasion, a molecule undergoing nucleophilic substitution may contain a nucleophilic group that participates in the reaction. This is known as the neighboring group effect and usually is revealed by retention of stereochemistry in the nucleophilic substitution reaction or by an increase in the rate of the reaction. 

Neighboring group effects rate of reaction. Anchlmeric assistance... 

This is another example of a neighboring group effect, one that shows itself not in stereochemistry but in rate of reaction. Sulfur helps to push out chloride ion, forming a cyclic sulfonium ion in the process. As fast as it is formed, this intermediate reacts with water to yield the product. 

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