- Regio- And diastereoselective synthesis of: Trans -3,4-diaryldihydrocoumarins via metal-free [4+2] annulation of ynamides with o -hydroxybenzyl alcohols
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An efficient regio- and diastereoselective method for the construction of valuable trans-3,4-diaryldihydrocoumarins via metal-free [4+2] annulation of ynamides with o-hydroxybenzyl alcohols has been developed. Ynamides are first treated as 2-π partners to react with o-hydroxybenzyl alcohols via traceless sulfonamide directing groups, affording trans-3,4-diaryldihydrocoumarins in good yields with high regio- and diastereoselectivities. This metal-free methodology is also characterized by a wide substrate scope, good functional group tolerance, and efficiency on a gram scale.
- Luo, Wen-Feng,Ye, Long-Wu,Li, Long,Qian, Peng-Cheng
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supporting information
p. 5032 - 5035
(2021/05/28)
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- Multicomponent Synthesis of Iminocoumarins via Rhodium-Catalyzed C - H Bond Activation
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We herein establish a multicomponent annulation method for the synthesis of valuable iminocoumarins using aryl thiocarbamates, internal alkynes, and sulfonamides as starting materials, which are safe and readily available. The key step is a Rh-catalyzed a
- Chen, Zhan,Jin, Shengnan,Jiang, Wenyao,Zhu, Feimin,Chen, Yuqi,Zhao, Yingwei
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supporting information
p. 11006 - 11013
(2020/09/18)
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- The light “on-off” stepwise one-pot method for 3,4-diaryl coumarins with potential AIE properties
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An efficient one-pot method involving visible-light-induced cyclization and Pd-catalyzed Suzuki cross-coupling processes to construct 3,4-diaryl coumarins is developed. Under the light on-off optimized conditions, a series of alkynoates and aryl boronic a
- Zhang, Huijuan,Li, Qingrui,Yin, Yunnian,Kim, Jung Keun,Huang, Mengmeng,Li, Yabo,Wu, Yangjie
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- Zn(II)-Catalyzed One-Pot Synthesis of Coumarins from Ynamides and Salicylaldehydes
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A highly efficient and straightforward synthesis of diversely substituted coumarins from ynamides and salicylaldehydes in the presence of Zn(II) catalyst has been developed. The sulfonamide moiety of ynamides was successfully recycled in this process, serving as an effective traceless directing group for high regioselectivity in the bond-forming event. The advantages of this protocol are good functional group tolerance, broad substrate scope, simple and high-yielding reaction, recovery/reuse of the sulfonamides, low catalyst loading of inexpensive catalyst, and, by these merits, a more cost-effective and greener process.
- Yoo, Huen Ji,Youn, So Won
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p. 3422 - 3426
(2019/05/10)
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- Visible-light-driven copper-catalyzed aerobic oxidative cascade cyclization of N-tosylhydrazones and terminal alkynes: Regioselective synthesis of 3-arylcoumarins
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We present the first example of sustainable, intuitive, highly regioselective, visible-light-driven copper catalyzed aerobic oxidative cascade cyclization of N-tosylhydrazones with terminal alkynes for the preparation of 3-arylcoumarins at room temperature. This operationally simple methodology has been successfully applied to a wide range of N-tosylhydrazones and alkynes (49 examples), and proceeds well to afford biologically active compounds, such as monoamine oxidase B (MAO-B) inhibitor and horseradish peroxidase (HRP) inhibitor, in satisfactory yields under mild conditions. Furthermore, mechanistic studies suggest that the reaction proceeds via a copper(ii)-superoxo or -peroxo complex mediated oxidative annulation of terminal alkynes, as evidenced by 18O2 isotopic-labelling experiments.
- Ragupathi, Ayyakkannu,Sagadevan, Arunachalam,Charpe, Vaibhav Pramod,Lin, Chun-Cheng,Hwu, Jih-Ru,Hwang, Kuo Chu
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supporting information
p. 5151 - 5154
(2019/05/10)
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- Method for synthesizing coumarin compound in one step
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The invention discloses a method for synthesizing a coumarin compound in one step. Starting from simple and easy-to-obtain starting materials, the method disclosed by the invention cost-efficiently and efficiently synthesizes the 3,4-substrituted coumarin compound under mild conditions. With phenol as a material, a phenoxyamide compound is obtained, the phenoxyamide compound, carbon monoxide and alkyne are heated to 45 DEG C to 70 DEG C under normal pressure, so that reaction takes place, and thereby the 3,4-substrituted coumarin compound is obtained in one step. In reaction, an external oxidant does not need to be added, conditions are mild, the reaction yield is high, and the adaptability is good. In case of reaction with asymmetric alkyne, the 3-site and the 4-site of the obtained coumarin compound have unique selectivity.
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Paragraph 0031; 0032
(2018/05/16)
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- Synthesis of Polycyclic Heteroaromatic Coumarins via Photoinduced Dehydrogenative Annulation of 4-Phenyl-3-heteroarylcoumarins
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An efficient, oxidant and metal-free synthesis of polycyclic heteroaromatic coumarins was developed. H-Furo[2′,3′:3,4]naphtho[2,1-c]chromen-4-one (2a-2f), 1H-benzofuro[2′,3′:3,4]naphtho[2,1-c]chromen-1-one (2g-2j), and 4H-thieno[2′,3′:3,4]naphtho[2,1-c]ch
- Shi, Juan,Kang, Yang,Wang, Tao,Liang, Yong,Zhang, Zunting
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p. 13940 - 13948
(2018/11/30)
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- One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na2S2O8
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Various 4-aryl-3-bromocoumarins were smoothly obtained in moderate yields in one pot by treating 3-aryl-2-propynoic acids with diaryliodonium triflates and K2CO3 in the presence of CuCl, followed by the reaction with tetrabutylammoni
- Sasaki, Teppei,Moriyama, Katsuhiko,Togo, Hideo
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supporting information
p. 345 - 353
(2018/02/19)
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- Microwave-assisted cyclization under mildly basic conditions: Synthesis of 6 h -benzo [c] chromen-6-ones and their 7,8,9,10-tetrahydro analogues
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Aryl 2-bromobenzoates and aryl 2-bromocyclohex-1-enecarboxylates are cyclized by microwave irradiation in dimethylformamide in the presence of K2CO3 to give the corresponding 6H-benzo[c]chromen-6-ones and their 7,8,9,10-tetrahydro analogues, respectively, in 50-72% yields. Aryl 3-bromoacrylates are also converted into 2H-chromen-2-ones under the employed conditions.
- Dao, Pham Duy Quang,Ho, Son Long,Lim, Ho-Jin,Cho, Chan Sik
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p. 4140 - 4146
(2018/04/14)
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- Nickel-Catalyzed Arylative Carboxylation of Alkynes with Arylmagnesium Reagents and Carbon Dioxide Leading to Trisubstituted Acrylic Acids
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Nickel-catalyzed arylcarboxylation of alkynes with arylmagnesium reagents and carbon dioxide (CO2, 1 atm) was realized in one pot. Various trisubstituted acrylic acids within an aryl group at the β-position have been prepared efficiently with good regioselectivity under mild conditions. The resulting products could be further transformed to benzoannelated cycles retaining CO2 as a one-carbon synthon.
- Wang, Sheng,Xi, Chanjuan
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supporting information
p. 4131 - 4134
(2018/07/15)
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- Access to coumarins by rhodium-catalyzed oxidative annulation of aryl thiocarbamates with internal alkynes
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A Rh-catalyzed annulation of aryl thiocarbamates with internal alkynes via C-H bond activation has been developed. This protocol provides a new route to 3,4-disubstituted coumarins.
- Zhao, Yingwei,Han, Feng,Yang, Lei,Xia, Chungu
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supporting information
p. 1477 - 1480
(2015/03/30)
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- Rhodium-catalyzed direct coupling of benzothioamides with alkenes and alkynes through directed C-H bond cleavage
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Rhodium-catalyzed direct coupling of benzothioamides with alkenes proceeds smoothly involving ortho-CH bond cleavage. The thioamides also couple with alkynes under similar conditions accompanied by desulfurization and CN bond cleavage to produce indenone derivatives.
- Yokoyama, Yuki,Unoh, Yuto,Bohmann, Rebekka Anna,Satoh, Tetsuya,Hirano, Koji,Bolm, Carsten,Miura, Masahiro
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p. 1104 - 1106
(2015/09/02)
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- Synthesis of coumarins via PIDA/I2-mediated oxidative cyclization of substituted phenylacrylic acids
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A variety of functionalized coumarins were synthesized from substituted phenylacrylic acids via PIDA/I2-mediated and irradiation-promoted oxidative carbon-oxygen bond formation. Our studies show that the oxygen in the pendant carboxylic acid group cyclizes favorably to the aryl ring that is cis to it. The main advantages of this method include good functional group tolerance and the transition-metal-free characteristic. The Royal Society of Chemistry 2013.
- Li, Jinming,Chen, Huiyu,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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p. 4311 - 4320
(2013/04/24)
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- Nickel-catalyzed cycloaddition of o -arylcarboxybenzonitriles and alkynes via cleavage of two carbon - Carbon σ bonds
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An intermolecular cycloaddition reaction has been developed, where o-arylcarboxybenzonitriles react with alkynes to afford coumarins in the presence of Ni(0)/P(CH2Ph)3/MAD as a catalyst. The reaction process displays an unusual mechanistic feature - the cleavage of two independent C - CN and C - CO bonds.
- Nakai, Kenichiro,Kurahashi, Takuya,Matsubara, Seijiro
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supporting information; experimental part
p. 11066 - 11068
(2011/09/14)
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- General and efficient route for the synthesis of 3,4-disubstituted coumarins via Pd-catalyzed site-selective cross-coupling reactions
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(Chemical Equation Presented) Palladium-catalyzed site-selective cross-coupling reactions of 3-bromo-4-trifloxycoumarin or 3-bromo-4- tosyloxycoumarin provide an efficient and facile route for the synthesis of 3,4-disubstituted coumarins, which include 3,
- Zhang, Liang,Meng, Tianhao,Fan, Renhua,Wu, Jie
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p. 7279 - 7286
(2008/02/11)
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- An ionic O → α- and β-vinyl carbamoyl translocation of 2-(O-carbamoyl) stilbenes
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(Equation Presented) New anionic oxygen to α- and β-vinyl carbamoyl migration reactions, 17a and 26a-c → 18 and 30a-c, proceed under LDA-mediated conditions leading stereoselectively to highly substituted stilbenes bearing electron-donating and -withdrawing substituants. Compounds 17a and 26a-c are prepared by combination of efficient, directed ortho metalation, Sonogashira, and Suzuki-Miyaura cross-coupling procedures.
- Reed, Mark A.,Chang, Michelle T.,Snieckus, Victor
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p. 2297 - 2300
(2007/10/03)
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- Efficient synthesis of 3-substituted coumarins
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The Mukaiyama's esterification protocol, using 2-chloro-1-methylpyridinium iodide-triethylamine reagent, has been successfully exploited to provide rapid access to a variety of 3-substituted coumarins in satisfactory yields.
- Mashraqui, Sabir H.,Vashi, Dhaval,Mistry, Hitesh D.
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p. 3129 - 3134
(2007/10/03)
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- Synthesis of coumarins catalyzed by heterobimetallic Co/Rh nanoparticles
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Described here is the use of cobalt/rhodium (CO2Rh2) heterobimetallic nanoparticles in the catalytic synthesis of coumarins via cyclocarbonylation of alkynes with 2-iodophenol under 1 atm of carbon monoxide and reaction of phenol wit
- Park, Kang Hyun,Jung, Il Gu,Chung, Young Keun
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p. 2541 - 2544
(2007/10/03)
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- Palladium-Catalyzed Carbonylative Annulation of Internal Alkynes: Synthesis of 3,4-Disubstituted Coumarins
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The palladium-catalyzed annulation of internal alkynes by o-iodophenols in the presence of CO results in exclusive formation of coumarins. No isomeric chromones have been observed. The best reaction conditions utilize the 2-iodophenol, 5 equiv of alkyne, 1 atm of CO, 5 mol% Pd(OAc)2, 2 equiv of pyridine, and 1 equiv of n-Bu4NCl in DMF at 120°C. The use of a sterically unhindered pyridine base is essential to achieve high yields. A wide variety of 3,4-disubstituted coumarins containing alkyl, aryl, silyl, alkoxy, acyl, and ester groups have been prepared in moderate to good yields. Mixtures of regioisomers have been obtained when unsymmetrical alkynes are employed. 2-Iodophenols with electron-withdrawing and electron-donating substituents and 3-iodo-2-pyridone are effective in this annulation process. The reaction is believed to proceed via (1) oxidative addition of the 2-iodophenol to Pd(0), (2) insertion of the alkyne triple bond into the aryl-palladium bond, (3) CO insertion into the resulting vinylic carbon-palladium bond, and (4) nucleophilic attack of the phenolic oxygen on the carbonyl carbon of the acylpalladium complex with simultaneous regeneration of the Pd(0) catalyst. This annulation process is the first example of intermolecular insertion of an alkyne occurring in preference to CO insertion.
- Kadnikov, Dmitry V.,Larock, Richard C.
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p. 9423 - 9432
(2007/10/03)
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- Synthesis of coumarins via palladium-catalyzed carbonylative annulation of internal alkynes by o-lodophenols
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(matrix presented) A variety of substituted coumarins have been prepared in good yields by the palladium-catalyzed coupling of o-iodophenols with internal alkynes and 1 atm of carbon monoxide. Unlike most of the previous work on the palladium-catalyzed carbonylation of alkynes, the insertion of the internal alkyne occurs in preference to the insertion of CO.
- Kadnikov, Dmitry V.,Larock, Richard C.
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p. 3643 - 3646
(2007/10/03)
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- SYNTHESIS OF 3-PHENYLBENZOBENZOPYRANOINDAZOL-8(3H)-ONES AND BENZOPHENANTHROPYRAN-9-ONES BY PHOTOOXIDATION OF 3-ARYL-4-(1-PHENYL-1H-PYRAZOL-4-YL)COUMARINS AND 3,4-DIARYLCOUMARINS
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3-Aryl-4-(1-phenyl-1H-pyrazol-4-yl)coumarins (4) and 3,4-diarylcoumarins (5) were synthesised by reaction of 1-phenyl-4-(2'-hydroxybenzoyl)pyrazols (1) and 2-hydroxybenzophenone (2) respectively with arylacetyl chlorides (3) under Phase Transfer Catalysis
- Sabitha, G.,Reddy, G. Jagath,Rao, A. V. Subba
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p. 639 - 650
(2007/10/02)
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- A General Synthesis of 3,4-Disubstituted Coumarins
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The complex of POCl3 and the substituted N,N-diethylacetamide is condensed with substituted o-hydroxy-acetophenones and -benzophenones to afford 3,4-disubstituted coumarins (1a-k).
- Patil, Vinayak O.,Kelkar, Shriniwas L.,Wadia, Murzban S.
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p. 674 - 675
(2007/10/02)
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