90767-19-4

Upstream product

• 591-20-8 3-Bromophenol 
• 141-97-9 ethyl acetoacetate 
• 352287-96-8 (E)-3-(4-bromophenyl)but-2-enoic acid ethyl ester 
• 90772-57-9 (E)-3-(4-bromo-phenyl)but-2-enoic acid 
• 621-42-1 meta-hydroxyacetanilide 
• 66611-72-1 N-(4-methyl-2-oxo-2H-chromen-7-yl)acetamide 
• 26093-31-2 7-amino-4-methylcoumarin. 

Relevant academic research and scientific papers

One Photocatalyst, n Activation Modes Strategy for Cascade Catalysis: Emulating Coumarin Biosynthesis with (-)-Riboflavin

Generating molecular complexity using a single catalyst, where the requisite activation modes are sequentially exploited as the reaction proceeds, is an attractive guiding principle in synthesis. This requires that each substrate transposition exposes a catalyst activation mode (AM) to which all preceding or future intermediates are resistant. While this concept is exemplified by MacMillan's beautiful merger of enamine and iminium ion activation, examples in other fields of contemporary catalysis remain elusive. Herein, we extend this tactic to organic photochemistry. By harnessing the two discrete photochemical activation modes of (-)-riboflavin, it is possible to sequentially induce isomerization and cyclization by energy transfer (ET) and single-electron transfer (SET) activation pathways, respectively. This catalytic approach has been utilized to emulate the coumarin biosynthesis pathway, which features a key photochemical E → Z isomerization step. Since the ensuing SET-based cyclization eliminates the need for a prefunctionalized aryl ring, this constitutes a novel disconnection of a pharmaceutically important scaffold.

Aziridinyl Fluorophores Demonstrate Bright Fluorescence and Superior Photostability by Effectively Inhibiting Twisted Intramolecular Charge Transfer

Replacing conventional dialkylamino substituents with a three-membered aziridine ring in naphthalimide leads to significantly enhanced brightness and photostability by effectively suppressing twisted intramolecular charge transfer formation. This replacement is generalizable in other chemical families of fluorophores, such as coumarin, phthalimide, and nitrobenzoxadiazole dyes. In highly polar fluorophores, we show that aziridinyl dyes even outperform their azetidinyl analogues in aqueous solution. We also proposed one simple mechanism that can explain the vulnerability of quantum yield to hydrogen bond interactions in protonic solvents in various fluorophore families. Such knowledge is a critical step toward developing high-performance fluorophores for advanced fluorescence imaging.

Design, synthesis, and biological and crystallographic evaluation of novel inhibitors of plasmodium falciparum enoyl-ACP-reductase (pf fabi)

Malaria, a disease of worldwide significance, is responsible for over one million deaths annually. The liver-stage of Plasmodium's life cycle is the first, obligatory, but clinically silent step in malaria infection. The P. falciparum type II fatty acid biosynthesis pathway (PfFAS-II) has been found to be essential for complete liver-stage development and has been regarded as a potential antimalarial target for the development of drugs for malaria prophylaxis and liver-stage eradication. In this paper, new coumarin-based triclosan analogues are reported and their biological profile is explored in terms of inhibitory potency against enzymes of the PfFAS-II pathway. Among the tested compounds, 7 and 8 showed the highest inhibitory potency against Pf enoyl-ACP-reductase (PfFabI), followed by 15 and 3. Finally, we determined the crystal structures of compounds 7 and 11 in complex with PfFabI to identify their mode of binding and to confirm outcomes of docking simulations.