Transition-State Structure for the Quintessential SN2 Reaction of a Carbohydrate: Reaction of α‑Glucopyranosyl Fluoride with Azide Ion in Water
journal contributionposted on 2014-09-03, 00:00 authored by Jefferson Chan, Natalia Sannikova, Ariel Tang, Andrew J. Bennet
We report that the SN2 reaction of α-d-glucopyranosyl fluoride with azide ion proceeds through a loose (exploded) transition-state (TS) structure. We reached this conclusion by modeling the TS using a suite of five experimental kinetic isotope effects (KIEs) as constraints for the calculations. We also report that the anomeric 13C-KIE is not abnormally large (k12/k13 = 1.024 ± 0.006), a finding which is at variance with the previous literature value (Zhang et al. J. Am. Chem. Soc. 1994, 116, 7557).