Pd-catalyzed chemo-selective mono-arylations and bis-arylations of functionalized 4-chlorocoumarins with triarylbismuths as threefold arylating reagents
作者:Maddali L.N. Rao、Abhijeet Kumar
DOI:10.1016/j.tet.2014.07.059
日期:2014.9
4-chlorocoumarins were studied under palladium catalysis usingtriarylbismuths as threefoldarylatingreagents. The high reactivity of 4-chlorocoumarins was demonstrated delivering mono- and bis-arylation products in a chemo-selective manner. The reaction conditions employed are simple, robust and the threefold coupling reactivity of triarylbismuthreagents was witnessed with good to high yields in 2–4 h conditions
Eine neue Reaktion von 4-Hydroxycumarinen und Synthese von 4-Fluorcumarinen
作者:Heinz-Jürgen Bertram、Stefan Böhm、Liborius Born
DOI:10.1055/s-1991-26611
日期:——
A Novel Reaction of 4-Hydroxycoumarins and Synthesis of 4-Fluorocoumarins 6-Chlorohydroxycoumarins dimerise on reaction with sulfur(IV) fluoride to 6,8′-dichloro-2,2,4,4-tetrafluoro-4′-oxospiro[2H-1-benzopyran-3(4H), 2′(4′H)-[1]benzopyrano[3,4-d][1,3]oxathiazole]. The novel 4-Fluorocoumarins are obtained from the corresponding 4-Chlorocoumarins by an halogen-exchange reaction.
[EN] OPTICALLY ACTIVE DEVICES<br/>[FR] DISPOSITIFS OPTIQUEMENT ACTIFS
申请人:MERCK PATENT GMBH
公开号:WO2022128832A1
公开(公告)日:2022-06-23
The present invention relates to novel ophthalmic devices comprising polymerized compounds comprising a photoactive chromophore, said polymerized compounds, and special monomer compounds being particularly suitable for compositions and ophthalmic devices. The present invention is also directed to a process of changing the optical properties of said ophthalmic device or a precursor article for an ophthalmic device.
the assembly of 4,5-fused coumarin scaffolds. This protocol employs silver-catalyzed oxidativedecarboxylation for the generation of alkylradicalsfrom carboxylic acids, which were used as radical precursors. This method has also been extended to a diverse range of carbon-centered radicals generated from 2-oxo acids, a 1,3-dicarbonyl compound, isopropanol and acetone.