Marlier John F, Fogle Emily J, Redman Richard L, Stillman Anthony D, Denison Matthew A, Robins Lori I
University of Washington-Bothell , Bothell, Washington 98011, United States.
J Org Chem. 2015 Feb 6;80(3):1905-8. doi: 10.1021/jo502472m. Epub 2015 Jan 12.
The carbonyl-C, carbonyl-O, and leaving-S kinetic isotope effects (KIEs) were determined for the hydrolysis of formylthiocholine. Under acidic conditions, (13)k(obs) = 1.0312, (18)k(obs) = 0.997, and (34)k(obs) = 0.995; for neutral conditions, (13)k(obs) = 1.022, (18)k(obs) = 1.010, and (34)k(obs) = 0.996; and for alkaline conditions, (13)k(obs) = 1.0263, (18)k(obs) = 0.992, and (34)k(obs) = 1.000. The observed KIEs provided helpful insights into a qualitative description of the bond orders in the transition state structure.
测定了甲酰硫代胆碱水解反应的羰基碳、羰基氧和离去硫的动力学同位素效应（KIEs）。在酸性条件下，(13)k(obs)=1.0312，(18)k(obs)=0.997，(34)k(obs)=0.995；在中性条件下，(13)k(obs)=1.022，(18)k(obs)=1.010，(34)k(obs)=0.996；在碱性条件下，(13)k(obs)=1.0263，(18)k(obs)=0.992，(34)k(obs)=1.000。观察到的动力学同位素效应为过渡态结构中键级的定性描述提供了有用的见解。
