Rhodium(I)-Catalyzed Decarbonylative Aerobic Oxidation of Cyclic α-Diketones: A Regioselective Single Carbon Extrusion Strategy
作者:Gangadhararao Golime、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.7b03837
日期:2018.2.16
rhodium-catalyzed decarbonylative aerobic oxidation of cyclic α-diketones has been developed for the first time, where the regioselective formations of α-pyrones and isocoumarins have been achieved. The current decarbonylative aerobic oxidation pathway proceeds via the C–C bond cleavage followed by a C–O bond formation, representing a biomimetic oxidation approach to unsaturated six-membered cyclic
Photoinduced cyclization of alkynoates to coumarins with N-Iodosuccinimide as a free-radical initiator under ambient and metal-free conditions
作者:Zhihui Wang、Xuezhi Li、Lei Wang、Pinhua Li
DOI:10.1016/j.tet.2019.01.013
日期:2019.2
a free-radical initiator and under LED (380–385 nm) irradiation and metal-free conditions, the reaction of alkynoates underwent smoothly to afford the corresponding coumarins in high yields at room temperature with broad substrate scope via freeradical intramolecular cyclization and ester rearrangement.
Novel saccharinate-bridged palladium complexes for efficient C–O bond activation displaying promising luminescence properties
作者:M. Dolores Santana、Rocío García-Bueno、Gabriel García、Gregorio Sánchez、Joaquín García、Anant R. Kapdi、Minal Naik、Suhas Pednekar、José Pérez、Luis García、Eduardo Pérez、J. Luis Serrano
DOI:10.1039/c2dt12187e
日期:——
The synthesis of mono- and dinuclear cyclometallated palladium(II) complexes with deprotonated saccharinate ligands displaying different coordination modes is described. The new compounds were prepared by direct reaction between saccharine and the corresponding hydroxo-complexes [Pd(μ-OH)(C⁁N)}2] (C^N = 2-(2-pyridyl)phenyl (Phpy) I; = 7,8-benzoquinolyl (Bzq) II), showing a general formula [Pd(μ-sac)(C^N)}2]
An efficient protocol for the direct synthesis of 4-arylcoumarins via palladium-catalyzedoxidativeHeck coupling reaction of coumarins and arylboronicacids was developed. 4-Arylcoumarins were obtained in moderate to excellent yields, and the reaction also showed tolerance toward functional groups such as hydro, methoxy, diethylamino, nitro, and chloro groups.
Synthesis of 4-arylcoumarins via palladium-catalyzed arylation/cyclization of ortho-hydroxylcinnamates with diaryliodonium salts
作者:Yang Yang、Jianwei Han、Xunshen Wu、Shujia Xu、Limin Wang
DOI:10.1016/j.tetlet.2015.04.082
日期:2015.6
ortho-hydroxylcinnamate ester derivatives by using diaryliodonium(III) salts has been developed. With this method, 4-arylcoumarins were easily prepared in good to excellent yields under base-free conditions. Additionally, this protocol provided an efficient alternative for the preparation of related 4-arylated coumarin compounds which are useful in the access to 5-lipoxygenaseinhibitors.