Definition of nucleophilic catalysis

Catalysis by a Lewis base, involving formation of a Lewis adduct as a reaction intermediate. For example, the hydrolysis of acetic anhydride in aqueous solution catalysed by pyridine:

C5H5N + (CH3CO)2O [C5H5NCOCH3]+ + CH3CO2-

[C5H5NCOCH3]+ + H2O C5H5N + CH3CO2H + H+aq

See also electrophilic, nucleophilicity.