Electron releasing/donating group

The answer really depends on what each nucleophile is reacting with. However, because the electron-releasing methyl group pushes electron density toward oxygen, we expect that more electron density on MeO will make it more reactive (more nucleophilic) than hydroxide (HO ). Acetate is a resonance stabilized anion, so there is less electron density available for donation (weaker nucleophile). In ethoxide, the electron density is effectively concentrated on oxygen and more available for donation a stronger nucleophile. 

FIGURE 3.23 Protectors that are more sensitive or more stable to acidolysis than the parent protector. Electron-donating groups favor protonation and hence aid cleavage electron-withdrawing groups disfavor protonation. The numbers indicate the relative ease of cleavage, which also depends on the stability of the carbenium ion that is released. Bpoc = 2-(biphenyl-4-yl)-prop-2-yloxycarbonyl. 

Shima, Smid and Szwarc (56) studied the effect of the methyl substitution in the polymerization of butadiene, isoprene and dimethyl-butadiene. They showed that the electron-donating methyl group decreased the rate of polymerization catalysed by polystyrylsodium. This same electron releasing effect of the methyl is seen, since the 3.4-structure, not 1.2-structure, is produced predominantly from isoprene. This results from the anionic propagation mechanism of the alkali metal alkyl catalysed polymerization of dienes which produced 1.2 and 3.4-structures. 

For the acid-catalysed hydrolysis of benzanilides substituted in the aromatic amine moiety p = 1.66. (8 ).The positive sign of the reaction constant can be easily understood in terms of the hydrolysis mechanism. The protonation of the carbonyl oxygen should not be very much affected by the polarity of a remote substituent in the N-ary 1 group. On the other hand, the rate of approach of a nucleophile depends upon the electrophilicity of the carbonyl carbon, which in turn is modified by the electron -releasing or electron - donating properties of the N-substituent. 

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