Abstract

AbstractExamples of geometric alkene isomerization in nature are often limited to the net exergonic direction (ΔG°<0), with the antipodal net endergonic processes (ΔG°>0) comparatively under‐represented. Inspired by the expansiveness of the maleate to fumarate (Z→E) isomerization in biochemistry, we investigated the inverse E→Z variant to validate nO→πC=O* interactions as a driving force for contra‐thermodynamic isomerization. A general protocol involving selective energy transfer catalysis with inexpensive thioxanthone as a sensitizer (λmax=402 nm) is disclosed. Whilst in the enzymatic process nO→πC=O* interactions commonly manifest themselves in the substrate, these same interactions are shown to underpin directionality in the antipodal reaction by shortening the product alkene chromophore. The process was validated with diverse fumarate derivatives (>30 examples, up to Z:E>99:1), including the first examples of tetrasubstituted alkenes, and the involvement of nO→πC=O* interactions was confirmed by X‐ray crystallography.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

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.