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General Acid/Base Catalysis

General Acid/Base Catalysis

Charge development in the TS can be decreased by either donation of a proton from general acids (like acetic acid or a protonated indole ring) to an atom such as a carbonyl O which develops a partial negative charge in the TS when it is attached by a nucleophile. Proton donation decreases the developing negative in the TS. Alternatively, a nucleophile such as water which develops a partial positive charge in the TS as it begins to form a bond to an electrophilic C in a carbonyl can be stabilized by the presence of a general base (such as acetate or the deprotonated indole ring). Proton abstraction decreases the developing positive charge

Figure:; CHARGE DEVELOPMENT IN THE TRANSITION STATE FOR ESTER HYDROLYSIS

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Figure:; MECHANISM OF GENERAL ACID CATALYSIS

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Figure:; MECHANISM OF GENERAL BASE CATALYSIS

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