Nucleophilic Reactivity toward Acetyl Chloride in Water

Article abstract of DOI:10.1021/ja00329a040

Rate constant ratios for the reactions of acetyl chloride with nucleophilic reagents in water containing 2.5percent (v/v) dioxane were determined by product analysis.The rate constants show a small dependence on the basicity of primary amines, with β_nuc=0.25, and are assigned to rate-limiting attack of the nucleophile.Pyridines with pK_a>5 behave similarly, with β_nuc=0.24, but less basic pyridines react more slowly.Several "α-effect" amines and anionic oxygen nucleophiles show small rate enhancements that are attributed to increases in the rate of nucleophilic attack.The rate constants do not fit the N+ correlation equation, and it is concluded that the reactions of nucleophilic reagents with acyl compounds are not satisfactorily correlated by simple modifications of this equation.