Kwan Eugene E, Park Yongho, Besser Harrison A, Anderson Thayer L, Jacobsen Eric N
Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.
J Am Chem Soc. 2017 Jan 11;139(1):43-46. doi: 10.1021/jacs.6b10621. Epub 2016 Dec 29.
Polarization transfer is demonstrated as a sensitive technique for the measurement of isotopic fractionation of protonated carbons at natural abundance. This method allows kinetic isotope effects (KIEs) to be determined with substantially less material or shorter acquisition time compared with traditional experiments. Computations quantitatively reproduce the KIEs in a Diels-Alder reaction and a catalytic glycosylation. The glycosylation is shown to occur by an effectively concerted mechanism.
极化转移被证明是一种用于测量天然丰度下质子化碳的同位素分馏的灵敏技术。与传统实验相比,该方法能够用少得多的材料或更短的采集时间来确定动力学同位素效应(KIEs)。计算定量地重现了狄尔斯-阿尔德反应和催化糖基化反应中的KIEs。结果表明,糖基化反应是通过一种有效的协同机制发生的。