solution, to 6.2 when bound. The accelerated deprotonation by 6A-amino-6A-deoxy-beta-cyclodextrin is reflected in the enhanced rates of hydrogen-deuterium exchange of the nitrotoluene in deuterium oxide, and in the conjugate addition of the nitrotoluene to methyl vinyl ketone in aqueous solution.
6A-
氨基-6A-脱氧β-
环糊精提高了4-叔丁基-α-
硝基甲苯的去质子化速率。在pH 6.0、6.5和7.0下,与
环糊精结合的物质kinc = 4 x 10(-3),9 x 10(-3)和19 x 10(-3)s(-1)的反应速率常数。分别在0.1 mol dm(-3)
磷酸盐
水溶液中在298 K下含有1%
甲醇。每个pH值10次。在相同条件下,6A-二甲基
氨基-6A-脱氧-β-
环糊精和6A-(2-
氨基乙基
氨基)-6A-脱氧-β-
环糊精更有效。在pH 6.0、6.5和7.0下,对于前者,kinc = 3 x 10(-2),7 x 10(-2)和12 x 10(-2)s(-1),而对于后者,kinc = 4 x 10(-2),5 x 10(-2)和9 x 10(-2)s(-1)。每种
环糊精还将
硝基甲苯的pKa从游离溶液中的6.8降低到6。绑定时为2。6A-
氨基-6A-脱氧β-
环糊精的加速去质子反