Abstract
Axially chiral enantiomeric 2-pyridylimino-3-pyridyl-thiazolidine-4-ones and -thiones have been synthesized and their rotational barriers around the N-3C(pyridyl) bond have been determined by variable temperature NMR or by thermal racemization of the micropreparatively resolved enantiomers. Rotational barriers of the unprotonated compounds ranged from 46 to 116kJ/mol, depending on the substituent on the N-3-pyridyl ring and on the exocyclic oxygen or sulfur atoms of the thiazolidine ring. Protonation of the pyridine nitrogens by TFA caused a decrease in the barrier to the rotation by stabilizing the transition state of the rotations via hydrogen bonding interactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.