153136-77-7Relevant academic research and scientific papers
Visible-Light-Induced C(sp2)-C(sp3) Coupling Reaction for the Regioselective Synthesis of 3-Functionalized Coumarins
Li, Hanjie,Lin, Zhenwei,Lu, Ping,Qiao, Li,Wang, Yanguang,Xie, Jianwei,Zhang, Ke
supporting information, p. 9552 - 9562 (2021/07/26)
A photocatalysis strategy for the regioselective synthesis of 3-functionalized coumarins is reported. With visible light irradiation, a direct and regioselective C(sp2)-C(sp3) coupling reaction of 3-(2-hydroxyphenyl)acrylates with ethers or thioethers occurs by using Ru(bpy)3Cl2·6H2O as a photocatalyst and TBHP as an oxidant. The cascade process involves alkenylation of the C(sp3)-H bond of ethers and lactonization, furnishing 3-alkylated coumarins as the final products. This approach is characterized by a broad substrate scope, mild reaction conditions, and simplified operation. The synthesis of 3-alkylated coumarins could be realized by a one-pot procedure, starting from commercially available salicylaldehyde.
Free radical scavenging and α-glucosidase inhibitory activity of (E)-methyl/ethyl-3-(2-hydroxyphenyl)acrylates
Harikrishna, G.,Hariprasad, K. Siva,Raju, B. China,Tiwari, A. K.,Zehra, A.
, p. 111 - 116 (2021/09/28)
(E)-Methyl/ethyl-3-(2-hydroxyphenyl)acrylates 3a-x have been prepared by the reaction of salicylaldehydes 1a-l with Wittig reagents such as methyl (triphenylphosphoranylidene)acetate 2a and ethyl (triphenylphosphoranylidene)acetate 2b in dry DCM at room t
Cascade Synthesis of 4-Arylcoumarins: Pd-Catalyzed Arylations and Cyclizations with (E)-Ethyl 3-(2-Hydroxyaryl)acrylates and Triarylantimony Difluorides
Kitamura, Yuki,Matsumura, Mio,Kato, Yukari,Murata, Yuki,Yasuike, Shuji
supporting information, p. 1652 - 1657 (2020/03/05)
Herein, we describe a simple general method for the synthesis of 4-arylcoumarins using pentavalent organoantimony compounds. The reactions of 3-(2-hydroxyaryl)acrylates with triarylantimony difluorides in the presence of Pd(OAc)2 (10 mol-%) and 2,2'-bipyridyl (10 mol-%) at 80 °C under aerobic conditions afforded 4-arylcoumarins in good-to-excellent yields. This protocol involves a cascade oxidative Heck-type arylation followed by cyclization, with all the aryl groups in the triarylantimony difluoride transferred to the coupling products. Triarylantimony difluorides resulted in better outcomes than those obtained with other pentavalent organoantimony or bismuth compounds.
Late-Stage Direct o-Alkenylation of Phenols by PdII-Catalyzed C?H Functionalization
Dou, Yandong,Kenry,Liu, Jiang,Jiang, Jianze,Zhu, Qing
supporting information, p. 6896 - 6901 (2019/05/07)
o-Alkenylation of unprotected phenols has been developed by direct C?H functionalization catalyzed by PdII. This work features phenol group as a directing group and realizes highly site-selective C?H bond functionalization of phenols to achieve the corresponding products in moderate to excellent yields at 60 °C. The advantages of this reaction include unprecedented C?H functionalization using phenol as a directing group, high regioselectivity, good substrate scope, mild reaction conditions, and high efficiency. To the best of our knowledge, this is the first example of a regioselective C?H alkenylation of unprotected phenols utilizing phenolic hydroxyl group as a directing group. The alkenylation of unprotected tyrosine and intramolecular cyclization are also successfully carried out under this catalytic system in good yields. Furthermore, this novel method enables a late-stage modification of complex phenol-containing bioactive molecules toward a diversity-oriented drug discovery.
3-Trifluoromethylated Coumarins and Carbostyrils by Radical Trifluoromethylation of ortho-Functionalized Cinnamic Esters
Chaabouni, Slim,Simonet, Florent,Fran?ois, Alison,Abid, Souhir,Galaup, Chantal,Chassaing, Stefan
supporting information, p. 271 - 277 (2017/01/24)
A method for the trifluoromethylation of ortho-hydroxycinnamic esters was developed to achieve the regioselective synthesis of 3-trifluoromethylated coumarins. The reaction was performed by using the Togni reagent as the CF3source under mild conditions and showed good functional- group tolerance. The scope of this copper-mediated method was further expanded to the synthesis of 3-trifluoromethylated carbostyrils starting from ortho-aminocinnamic derivatives. Interestingly, a sequential one-pot synthesis of 3-trifluoromethylated coumarins starting from salicylaldehydes was further developed. The mechanism of this cascade reaction was explored, and a radical pathway was found to be consistent with the obtained results.
Phosphine-catalyzed synthesis of highly functionalized coumarins
Henry, Christopher E.,Kwon, Ohyun
, p. 3069 - 3072 (2008/02/11)
2-Styrenyl allenoates are converted into cyclopentene-fused dihydrocoumarins through phosphine-catalyzed regio- and diastereoselective [3 + 2] cycloadditions. Remarkably, changing the solvent from THF to benzene promotes the conversion of the 2-(2-nitrostyrenyl) allenoate into a tricyclic nitronate through a previously undocumented mode of phosphine catalysis. This nitronate was subjected to efficient face-, regio-, and exo-selective 1,3-dipolar cycloadditions to provide tetracyclic coumarin derivatives.
Microwave-induced in situ Wittig reaction of salicylaldehydes with ethyl chloroacetate and triphenylphosphine in solventless system
Valizadeh,Shockravi,Heravi,Ghadim, H. Abbasi
, p. 718 - 720 (2007/10/03)
A variety of coumarins was prepared by an in situ Wittig reaction of salicylaldehydes, triphenylphosphine and ethyl chloroacetate using sodium methoxide/molecular sieves (3A) under solvent-free conditions.
An efficient route from coumarins to highly functionalized N-phenyl-2-quinolinones via Buchwald-Hartwig amination
Ullrich, Thomas,Giraud, Francis
, p. 4207 - 4211 (2007/10/03)
Multiple substituted N-phenyl-2-quinolinones were obtained in a convenient four-step route from a variety of commercially available coumarins, utilizing customised Buchwald-Hartwig amination protocols for the key reaction. Whereas simple aminolysis of cou
CONVENIENT SYNTHESIS OF A SIMPLE COUMARIN FROM SALICYLALDEHYDE AND WITTIG REAGENT (III): SYNTHESIS OF NITROCOUMARINS
Harayama, Takashi,Nakatsuka, Kazumitsu,Nishioka, Hiromi,Maurakami, Kyoko,Ohmori, Yukiko,et al.
, p. 2729 - 2738 (2007/10/02)
Reaction of nitrosalicylaldehydes (1) with carbethoxymethylenetriphenylphosphorane in Et2NPh, in Ph2O, and in the absence of solvent (neat) at 210-215 deg C was investigated.Reaction of 3-nitrosalicylaldehyde (1d) in Et2NPh afforded the benzoxazole (6) and the aminocoumarin (3e) along with the expected coumarin (3d).It was clarified that the origin of carbon-unit introduced for the formation of the benzoxazole ring came from the alkyl group of solvent.
