Inorganic Anionic Oxygen-Containing α-Nucleophiles-Effective Acyl Group Acceptors: Hydroxylamine Ranks First among the α-Nucleophile Series

摘要: Comparative analysis of the nucleophilicity inorganic oxygen-containing α-nucleophiles (hydroxylamine and ClO-, BrO--, HOO--, NH2O-, F- ions) covering pKa range from -2 to 13.81 toward 4-nitrophenyl esters (4-nitrophenyl acetate, p-toluenesulfonate, diethyl phosphate, ethyl ethylphosphonate, dimethylcarbamate) in water at 25°C (ionic strength μ 1.0, KCl) was performed terms extrathermodynamic Bronsted relation. It found for first time that hydroxylamine anion ranks among series α-nucleophiles. is more reactive than HOO- ion with respect acetate (by a factor ∼8), p-toluenesulfonate ∼4) dimethylcarbamate ∼10). The nucleophilicities NH2O- ions phosphate ethylphosphonate are comparable. Taking into account neutral exhibits an anomalously high reactivity, as compared not only common organic but also α-nucleophiles, it may be regarded unique α-nucleophile. Both its O-nucleophiles ensure rates acyl group transfer throughout wide pH.