Mechanisms of Orthogonal Photodecarbonylation Reactions of 3-Hydroxyflavone-Based Acid-Base Forms

               Marina Russo,^† Peter Štacko,^† Dana Nachtigallová,^‡ Petr Klán^†,^*

^†Department of Chemistry and RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic

^‡Institute of Organic Chemistry and Biochemistry, Flemingovo nam. 2, 16610 Prague, Czech Republic


Studies of the effects of CO have demonstrated its potential to produce a variety of beneficial
health outcomes, including anti-inflammatory, anti-bacterial effects, and antiproliferative effects
on cancer.[1] Therefore, carbon monoxide-releasing molecules (CORMs), biologically compatible
agents allowing for defined administration of carbon monoxide into living organisms to circumvent
its acute toxicity, are of special interest.[2] A precise spatial and temporal control over the CO
release can be achieved via activation of the CORM by light (photoCORMs).

A good photoCORM should be stable under ambient conditions and soluble in aerobic aqueous
environments. It should release CO using light at wavelengths that do not have the potential to
impart cellular damage and may exhibit fluorescence to enable tracking in the cell.

Understanding the mechanism is a key step for designing new derivatives with improved properties
for biological applications, such as water solubility, higher quantum yield and the absorption
spectra in the visible light region.

3-Hydroxy-2-phenyl-benzo[g]chromen-4-one has recently been shown to efficiently release CO upon
irradiation with blue light.[3] The detailed mechanism of the photochemically induced CO release
from this compound will be presented.
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[1] L. Vítek, H. Gbelcová, L. Muchová, R. Koníčková, J. Šuk, M. Zadinova, Z. Knejzlík, S. Ahmad, T.
Fujisawa, A. Ahmed, T. Ruml,  Digestive and Liver Disease 2014, 46 369-375.

[2] C. C. Romao, W. A. Blatter, J. D. Seixas, G. J. L. Bernades, Chem. Soc. Rev. 2012, 41,
3571-3583

[3] S. N. Anderson, J. M. Richards, H. J. Esquer, A. D. Benninghoff, A. M. Arif and L. M. Berreau,
ChemistryOpen, 2015, 4, 590–594.