Inductive electron-withdrawing effects

Inductive effects Electron-withdrawing groups make the carbonyl carbon more electrophilic and increase the reaction rate electron-donating groups make the carbonyl carbon less electrophilic and decrease the reaction rate. 

Resonance effects Electron donors slow the reaction withdrawers accelerate it. Inductive effects Electron withdrawers accelerate the reaction. 

The downfield shift caused by chlorine is what we might have expected from its inductive effect electron withdrawal lowers the electron density in the vicinity of the proton and thus causes deshielding. The effect of a substituent on the chemical shift is unquestionably the net result of many factors yet we shall often observe chemical shifts which strongly suggest that an inductive effect is at least one of the factors at work. 

The inductive effects (electron-withdrawing effects) of the hetero-substituted groups ... 

In salicyhc acid, the inductive effect (electron-withdrawal) of the OH group is expected to be more pronounced because of its proximity to the site where deprotonation will occur. 

Here the reaction is assisted by conjugative and hyperconjugative effects, and is retarded by the inductive effect which withdraws electrons from the reaction site. A similar effect is found in the addition of bromine to olefins (RCH=CH2) in acetic acid at 25°, viz-... 

Carboxylic acids are weak acids and m the absence of electron attracting substituents have s of approximately 5 Carboxylic acids are much stronger acids than alcohols because of the electron withdrawing power of the carbonyl group (inductive effect) and its ability to delocalize negative charge m the carboxylate anion (resonance effect)... 

A tertiary carbonium ion is more stable than a secondary carbonium ion, which is in turn more stable than a primary carbonium ion. Therefore, the alkylation of ben2ene with isobutylene is much easier than is alkylation with ethylene. The reactivity of substituted aromatics for electrophilic substitution is affected by the inductive and resonance effects of a substituent. An electron-donating group, such as the hydroxyl and methyl groups, activates the alkylation and an electron-withdrawing group, such as chloride, deactivates it. 

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