These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Manuscript - ChemRxiv.pdf (1.29 MB)
Boron-Enabled Geometric Isomerization of Small Alkene Fragments via Selective Energy Transfer Catalysis
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
The mammalian visual cycle epitomizes the importance of complex polyenes in biology. However, isomerization-based strategies to enable the sterodivergent construction of these important biomolecules from geometrically defined alkene linchpins remain conspicuously underdeveloped. Mitigating the thermodynamic constraints inherent to isomerization is further frustrated by the considerations of atom efficiency in idealized low molecular precursors. Herein, we report a general ambiphilic C3 scaffold that can be isomerized and bi-directionally extended. Predicated on highly efficient triplet energy transfer, the selective isomerization of β-15 borylacrylates is contingent on the participation of the boron p-orbital in the substrate chromophore. Rotation of the C(sp2)-B bond by 90° in the product renders re-excitation inefficient and endows directionality. This subtle stereoelectronic gating mechanism enables the stereocontrolled syntheses of well-defined retinoic acid derivatives.