Sensitive and Accurate 13C Kinetic Isotope Effect Measurements Enabled by Polarization Transfer

• DOI: 10.1021/jacs.6b10621
• Publication Date: 2016-12-25T00:25:20Z
• Authors: Eugene E. Kwan; Yongho Park; Harrison A. Besser; Thayer L. Anderson; Eric N. Jacobsen
• Keywords: Carbon Isotopes; Glycosylation; 550; Cycloaddition Reaction; General Chemistry; 540; Biochemistry; 01 natural sciences; 7. Clean energy; Catalysis; 0104 chemical sciences; Kinetics; Colloid and Surface Chemistry; Quantum Theory

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.