35283-06-8Relevant academic research and scientific papers
Practical synthesis of unsymmetrical diarylacetylenes from propiolic acid and two different aryl bromides
Tartaggia, Stefano,De Lucchi, Ottorino,Goossen, Lukas J.
, p. 1431 - 1438 (2012)
A palladium catalyst that mediates the one-pot sequential Sonogashira and decarboxylative coupling of propiolic acid with two different aryl bromides has been developed. Selective coupling of the first aryl bromide was achieved in the presence of a copper-free, monometallic catalyst generated in situ from allylpalladium chloride dimer and SPhos with tetra-n-butylammonium fluoride as the base in an N-methyl-2-pyrrolidone/water solvent mixture. Upon addition of another aryl bromide and raising the temperature from 50 to 80°C, the intermediate arylpropiolic acid underwent decarboxylative coupling to give the corresponding diarylacetylene. Thus, the new system permits a one-pot three-component synthesis of unsymmetrical diarylacetylenes from widely available aryl bromides, rather than expensive aryl iodides, and propiolic acid, rather than (trimethylsilyl)acetylene, as an inexpensive and easy-to-handle acetylene synthon. The process is highly selective, modular, and gives access to a wide range of unsymmetrical diarylacetylenes in good yields. A palladium-catalyzed three component synthesis of diaryl acetylenes has been optimized. Several disubstituted alkynes have been prepared from two different arylbromides and propiolic acid in good yields. Copyright
Silver-catalyzed Double Decarboxylative Radical Alkynylation/Annulation of Arylpropiolic Acids with α-keto Acids: Access to Ynones and Flavones under Mild Conditions
Meng, Mengting,Wang, Guofang,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
, p. 1218 - 1231 (2018/02/16)
Ynones are privileged building blocks in various organic syntheses of heterocyclic derivatives due to their multifunctional nature, and flavones are an important class of natural products with a wide range of biological activities. We describe the catalytic double decarboxylative alkynylation of arylpropiolic acids with α-keto acids. With Ag(I)/persulfate as the catalysis system, the valuable ynones bearing various substituents could be easily obtained. The introduction of hydroxyl substituent on ortho-site of α-keto acids make this strategy further applicable to the construction of flavone derivatives via heteroannulation in moderate to good yields with a similar silver-catalyzed system. The reactions proceed under relatively mild reaction conditions and tolerate a wide variety of functional groups. Control experiments indicated that both the reactions undergo radical processes. (Figure presented.).
