Synthesis of new quinolizinium-based fluorescent compounds and studies on their applications in photocatalysis

Abstract

Quinoliziniums, cationic aromatic heterocycles bearing a quaternary bridgehead nitrogen, have been widely applied to research areas, such as fluorescent dyes, DNA intercalators and ionic liquids. A library of new quinolizinium...

Quinolizinium-based fluorescent probes for formaldehyde detection in aqueous solution, serum, and test strip via 2-aza-Cope rearrangement

“…QCHO showed the emissive blue shi comparing with QA1 and QA2 because of more electron deactivation effect of the resulting aldehyde group than alkyl amine which correlate with DFT/TD-DFT calculations of quinolizinium in our previous work. 20 Interestingly, the uorescence colour change was clearly observed through 365 nm UV light irradiation from intense green to blue colour upon addition of FA, correlating with their emission wavelengths (Fig. 1b; inset images).…”

“…Moreover, using quinolizinium as a core reporter for sensor development has various advantages due to its good quantum yield, high water solubility due to cationic aromatic heterocycles, diversity of structural modification, and excellent photostability. 20 …”

“…Moreover, using quinolizinium as a core reporter for sensor development has various advantages due to its good quantum yield, high water solubility due to cationic aromatic heterocycles, diversity of structural modication, and excellent photostability. 20 The synthesis of QA1-2 probes was outlined in Scheme 3. Moreover, we synthesized QCHO for the photophysical property studies to compare with the photophysical properties of the 2aza-Cope reaction adducts from the reactions between QA1-2 and FA.…”

Fluorogenic Protein Labeling by Generation of Fluorescent Quinoliziniums Using [Cp*RhCl2]2

“…Various metals (Cu, Pd, Ru, Ir, Fe, and Au) have been used as catalysts for fluorogenic labeling in biological media and living systems, but the use of rhodium (Rh) remains underdeveloped . Recently, we have reported a [Cp*RhCl 2 ] 2 -catalyzed C–H activation and annulation reaction of internal alkynes and quinolines to yield fluorescent quinolizinium products in good yield . The advantages of rhodium catalysts include ease of synthesis, stability to air, high regioselectivity, high functional group compatibility, and good solubility and stability in aqueous medium. , Note that some literature reports have demonstrated the feasibility of using rhodium as a catalyst for bioconjugation.…”

Visible light photocatalytic one pot synthesis of Z-arylvinyl halides from E-arylvinyl acids with N-halosuccinimide

“…Our group has synthesized a series of new fluorescent quinolizinium compounds from quinolines and alkyne substrates. 13 Due to the high tunability and high excited state reduction potentials of the fluorescent quinolizinium compounds, we proposed that the quinolizinium compounds could be used as photocatalysts for the synthesis of Z -arylvinyl halides from α,β-unsaturated arylvinyl acids.…”