The transesterification rate of boronate esters with diols is tunable over 14 orders of magnitude. Rate acceleration is achieved by internal base catalysis, which lowers the barrier for proton transfer. Here we report a photoswitchable internal catalyst that tunes the rate of boronic ester/diol exchange over 4 orders of magnitude. We employed an acylhydrazone molecular photoswitch, which forms a thermally stable but photoreversible intramolecular H-bond, to gate the activity of the internal base catalyst in 8-quinoline boronic ester. The photoswitch is bidirectional and can be cycled repeatedly. The intramolecular H-bond is found to be essential to the design of this photoswitchable internal catalyst, as protonating the quinoline with external sources of acid has little effect on the exchange rate.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|State||Published - Jun 15 2022|
ASJC Scopus subject areas
- Colloid and Surface Chemistry
FingerprintDive into the research topics of 'Remote-Controlled Exchange Rates by Photoswitchable Internal Catalysis of Dynamic Covalent Bonds'. Together they form a unique fingerprint.
CCDC 2169146: Experimental Crystal Structure Determination
Barsoum, D. N. (Contributor), Kirinda, V. C. (Contributor), Kang, B. (Contributor) & Kalow, J. A. (Contributor), Cambridge Crystallographic Data Centre, 2022
DOI: 10.5517/ccdc.csd.cc2bt5gt, http://www.ccdc.cam.ac.uk/services/structure_request?id=doi:10.5517/ccdc.csd.cc2bt5gt&sid=DataCite