57279-48-8Relevant academic research and scientific papers
A palladium iodide catalyzed regioselective carbonylative route to isocoumarin and thienopyranone carboxylic esters
Carfagna, Carla,Centore, Roberto,Cuocci, Corrado,Della Ca', Nicola,Gabriele, Bartolo,Mancuso, Raffaella,Novello, Mariangela,Olivieri, Diego,Ziccarelli, Ida
, p. 164 - 182 (2021/12/20)
The reactivity of 2-alkynylbenzoic acids under PdI2/KI-catalyzed oxidative alkoxycarbonylation conditions, with oxygen (from air) as external oxidant and an alcohol as external nucleophile, has been studied. It was found that substrates with triple bond substituted with a bulky alkyl group, such as tert-butyl, selectively underwent a 6-endo-dig cyclization - alkoxycarbonylation pathway with ethanol or isopropanol as nucleophile, to give high value added isocoumarin-4-carboxylic esters in good to high yields (67–87%). When applied to alkynylthiophencarboxylic acids bearing an internal triple bond, the reaction turned out to be completely regioselective toward the formation of the corresponding alkyl thienopyranonecarboxylates ensuing from 6-endo-dig cyclization-alkoxycarbonylation, regardless the nature of the substituent on the triple bond and the external alcohol (54–91% yields). To confirm the structure of the products deriving from different kinds of substrates, and therefore to corroborate the proposed mechanistic pathways, the crystalline structures of 11 new compounds have been resolved by XRD analysis.
Modular synthesis of 3-substituted isocoumarinsviasilver-catalyzed aerobic oxidation/6-endoheterocyclization ofortho-alkynylbenzaldehydes
Wu, Hao,Wang, Yi-Chun,Shatskiy, Andrey,Li, Qiu-Yan,Liu, Jian-Quan,K?rk?s, Markus D.,Wang, Xiang-Shan
, p. 6657 - 6664 (2021/08/16)
A method involving silver-catalyzed aerobic oxidation/6-endoheterocyclization ofortho-alkynylbenzaldehydes to yield 3-substituted isocoumarins is described. The developed protocol allows convenient access to a range of synthetically useful 3-substituted isocoumarins and related fused heterocyclolactones in good to high yields, using silver tetrafluoroborate as the catalyst, and atmospheric oxygen as the terminal oxidant and the source of endocyclic oxygen. Mechanistic studies suggest the involvement of a free-radical pathway.
Lactonization of 2-Alkynylbenzoates for the Assembly of Isochromenones Mediated by BF3·Et2O
Zhang, Xiang,Wan, Xintong,Cong, Ying,Zhen, Xiaohua,Li, Qiao,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
, p. 10402 - 10411 (2019/08/20)
A general and efficient lactonization method of readily available 2-alkynylbenzoates affording biologically important isochromenones has been realized via a solely BF3·Et2O-mediated 6-endo-dig cyclization process under mild condition
Regioselective copper-mediated synthesis of thieno[2,3- c ]pyrane-7-one, Indolo[2,3- c ]pyrane-1-one, and indolo[3,2- c ]pyrane-1-one
Inack Ngi, Samuel,Guilloteau, Vincent,Abarbri, Mohamed,Thibonnet, Jerome
supporting information; experimental part, p. 8347 - 8354 (2011/12/04)
In the presence of copper(I) iodide, heteroaromatic Β-iodo-α, Β-unsaturated carboxylic acid systems opposed to terminal alkyne afford selectively 6-endo-dig cyclization products via a tandem coupling oxacyclization reaction.
