- Rhodium catalyzed carbon-hydrogen bond activation reaction for synthesizing isocoumarin derivative
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The invention belongs to the technical field of fine chemicals, and particularly relates to a preparation method of an isocoumarin derivative, and the isocoumarin derivative is a compound shown as a formula (I).
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Paragraph 0074-0078; 0089-0091
(2021/04/10)
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- Modular synthesis of 3-substituted isocoumarinsviasilver-catalyzed aerobic oxidation/6-endoheterocyclization ofortho-alkynylbenzaldehydes
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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.
- Wu, Hao,Wang, Yi-Chun,Shatskiy, Andrey,Li, Qiu-Yan,Liu, Jian-Quan,K?rk?s, Markus D.,Wang, Xiang-Shan
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p. 6657 - 6664
(2021/08/16)
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- Method for synthesizing isocoumarin derivative under catalysis of silver and application of isocoumarin derivative
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The invention belongs to the technical field of organic synthetic chemistry, and particularly relates to a method for synthesizing an isocoumarin derivative under catalysis of silver and application of the isocoumarin derivative. According to the method, 2-(phenylethynyl)benzaldehyde is taken as a model substrate, monovalent silver salt is taken as a catalyst, reaction is carried out at the temperature not lower than 30 DEG C, and the isocoumarin derivative is generated. In the field, 2-(phenylethynyl)benzaldehyde is used as a model substrate for the first time, and the isocoumarin derivative is prepared in one step under the catalytic action of the monovalent silver salt. The method is simple, convenient and efficient, the used raw materials are simple, easy to obtain and non-toxic, the steps are few, the conditions are mild, the cost is low, and the method is suitable for large-scale industrial production.
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Paragraph 0081-0086
(2021/05/12)
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- Indium-Catalyzed C?F Bond Transformation through Oxymetalation/β-Fluorine Elimination to Access Fluorinated Isocoumarins
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Fluorinated heterocycles have attracted much attention in the pharmaceutical and agrochemical industries. Many strategies have already been developed to achieve the synthesis of fluorinated heterocycles. Formidable challenges remain, however, in the synthesis of fluorinated isocoumarin derivatives that are among the most alluring structural motifs. Herein, the indium-catalyzed C?F bond transformation of 2-(2,2-difluorovinyl) benzoates is reported, which are readily accessible compounds, to give a diverse array of fluorinated isocoumarins. The present reaction proceeds smoothly using inexpensive reagents: a catalytic amount of indium salt in the presence of zinc salt. A theoretical calculation of potential energy profiles showed that the reaction consists of oxymetalation with the elimination of alkyl halide and the β-fluorine elimination.
- Yata, Tetsuji,Nishimoto, Yoshihiro,Chiba, Kouji,Yasuda, Makoto
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p. 8288 - 8294
(2021/05/21)
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- Palladium complexes with an annellated mesoionic carbene (MIC) ligand: Catalytic sequential Sonogashira coupling/cyclization reaction for one-pot synthesis of benzofuran, indole, isocoumarin and isoquinolone derivatives
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Two Pd(ii) complexes (1 and 2) featuring a fused π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand have been synthesized and structurally characterized. Both complexes effectively catalyze the one-pot synthesis of benzofuran starting from phenylacetylene and 2-iodophenol under mild conditions. Complex 1 is found to be an excellent catalyst for the straightforward access to a library of benzofuran, indole, isocoumarin and isoquinolone derivatives by the reaction of terminal alkynes with 2-iodo derivates of phenol, N-methyl aniline, benzoic acid and N-methyl benzamide, respectively. The general utility of the catalytic method is demonstrated using a variety of diversely substituted terminal alkynes and the corresponding desired products are obtained in good to excellent yields. On the basis of control experiments, a two-cycle mechanism is proposed which involves the Sonogashira coupling of 2-iodo derivatives with alkynes and the subsequent cyclization of the corresponding 2-alkynyl compounds.
- Bera, Jitendra K.,Daw, Prosenjit,Reshi, Noor U Din,Tyagi, Akshi
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supporting information
p. 15238 - 15248
(2020/11/18)
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- p-TSA-Based DESs as “Active Green Solvents” for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones
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In this paper, we describe the use of p-TSA based Deep Eutectic Solvents (DESs) as alternative environmental-friendly “active” solvents for the microwave-mediated synthesis of 6-substituted 3,4-fused 2-pyranones, and in particular isocoumarins, starting from 2-alkynyl-(hetero)arylcarboxylates. When the alkyne terminus bears a neutral or an electron-donating group (EDG), the reactions are fast, clean and highly regioselective, to give the 6-endo-dig cyclization products in good to excellent yields. For substrates bearing an electron-withdrawing group (EWG) on the alkyne end, the regioselectivity can be tuned by adding a small amount of silver(I) triflate as co-catalyst. DES was demonstrated to be reusable without loss of efficiency in terms of reaction yields. Based on experimental evidence and previous findings, two competitive mechanisms working simultaneously are proposed to explain the outcomes and the regioselectivity issues.
- Curti, Fabiola,Tiecco, Matteo,Pirovano, Valentina,Germani, Raimondo,Caselli, Alessandro,Rossi, Elisabetta,Abbiati, Giorgio
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p. 1904 - 1914
(2019/02/26)
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- Sulfoxonium Ylides as Carbene Precursors: Rhodium(III)-Catalyzed Sequential C?H Functionalization, Selective Enol Oxygen-Atom Nucleophilic Addition, and Hydrolysis
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Herein, we report a protocol for Rh(III)-catalyzed annulation reactions between oxazolines and sulfoxonium ylides via a sequence involving C?H activation, selective enol oxygen-atom nucleophilic addition, and hydrolysis. This practical, operationally simple protocol has a wide substrate range, excellent regioselectivity, and moderate to good yields.
- Huang, Yuanqiong,Lyu, Xueli,Song, Hongjian,Wang, Qingmin
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supporting information
p. 5272 - 5276
(2019/11/13)
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- Silver triflate/: P -TSA co-catalysed synthesis of 3-substituted isocoumarins from 2-alkynylbenzoates
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In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent yields. A conceivable reaction mechanism is proposed and supported by isotope-exchange tests, 1H NMR studies and ad hoc experiments.
- Gianni, Jonathan,Pirovano, Valentina,Abbiati, Giorgio
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supporting information
p. 3213 - 3219
(2018/05/17)
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- Reaction of arynes with trifluoroacetylated β-diketones: Novel formation of isocoumarins and phenanthrenes
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Polysubstituted isocoumarins were synthesized by the reaction of substituted 2-(trimethylsilyl)aryl triflates with trifluoromethylated β-diketones in the presence of CsF. The reaction proceeded through carbon-carbon bond insertion of aryne and intramolecular cyclization to form intermediates of alcohol anions, which extruded trifluoromethyl anion to afford isocoumarins. By using CuBr as a catalyst, 2 eq. of aryne reacted with β-diketones to afford phenanthrenes and 1,2-diarylethanones. Although reaction of 2-(trimethylsilyl)phenyl triflate with 1,1,1-trifluoro-4′-methylbenzoylacetone in the presence of CsF gave 3-(4′-methylphenyl)isocoumarin in 67% yield, addition of 0.2 eq. of CuCN resulted in the formation of 9-(4-methylbenzoyl)-10-trifluoromethylphenanthrene in 35% yield.
- Okuma, Kentaro,Tanabe, Yukiko,Fukami, Takuto,Ishibashi, Yuto
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- Ruthenium(IV) Intermediates in C?H Activation/Annulation by Weak O-Coordination
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Ruthenium(IV) complexes were identified as key intermediates of C?H/O?H activations by weak O-coordination. Thus, the annulations of sulfoxonium ylides by benzoic acids provided expedient access to diversely-decorated isocoumarins with ample scope. Detailed experimental and computational studies provided strong support for a facile BIES-C?H activation, along with cyclometalated ruthenium(IV) intermediates within a versatile ruthenium(II/IV) catalysis regime (BIES=base-assisted internal electrophilic substitution).
- Liang, Yu-Feng,Yang, Long,Rogge, Torben,Ackermann, Lutz
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supporting information
p. 16548 - 16552
(2018/10/26)
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- Medical intermediate diaryl ethylene oxide compound and synthesis method thereof
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The invention relates to a medical intermediate namely a diaryl ethylene oxide compound shown by the formula (I) as shown in the specification and a synthesis method thereof, wherein R1 is selected from H, halogen or C1-C6 alkyl; and R2 is selected from H, halogen, C1-C6 alkyl, C1-C6 alkoxy, halogenated C1-C6 alkyl or halogenated C1-C6 alkoxy. The invention also relates to a synthesis method of the derivative. The diaryl ethylene oxide compound can be used for one-step synthesis of isocoumarin compounds, thus having good application prospect and research value in the field of synthesis of theisocoumarin compounds.
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- Preparation method of isocoumarin medicament intermediate
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The invention relates to a preparation method of an isocoumarin medicament intermediate as shown in the following formula (5). The method has a reaction route as follows, and the method comprises thefollowing steps: S1: a compound in a formula (1) and a compound in a formula (2) are reacted under the existence of a palladium catalyst, a cationic ammonium compound, and alkali in an organic solvent, after the reaction ends, aftertreatment is carried out, in order to obtain a compound in a formula (3); S2: in an organic solvent, under the existence of an oxidizing agent, a self cyclization reaction of the compound in the formula (3) is carried out, and after the reaction ends, aftertreatment is carried out in order to obtain a compound in a formula (4); S3: under the existence of the palladium compound catalyst and the acidic compound, in a solvent, a reaction is carried out for the compound in the formula (4), and after the reaction ends, aftertreatment is carried out in order to obtainthe isocoumarin medicament intermediate as shown in the formula (5). According to the method, multiple technical characteristics of each step can be subjected to creative optimization, a whole new synthetic method and synthetic route is provided for preparing the isocoumarin compound, and the method has good industrialization prospect and latent application values.
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- Synthetic method of isocoumarin medicament intermediate
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The invention relates to a synthetic method of an isocoumarin medicament intermediate as shown in the following formula (I). The method comprises the following steps: under existence of a palladium compound catalyst and an acidic compound, in a solvent, a reaction is carried out for a compound as shown in the following formula (II), after the reaction ends, an isocoumarin medicament intermediate as shown in the formula (I) is obtained, wherein R1 is selected from H, halogen, or C1-C6 alkyls; R2 is selected from H, halogen, C1-C6 alkyls, C1-C6 alkoxys, halogenated C1-C6 alkyls or halogenated C1-C6 alkoxys. The method employs specific catalysts, acidic compounds and solvents, in order to provide good technical effects. The invention also provides a novel synthetic method of the compound in the formula (II) as a reactant, in order to provide a simple preparation method for synthesis of the isocoumarin medicament intermediate, and the method has good application prospects and research values.
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Paragraph 0100; 0101; 0102; 0103; 0116; 0117; 0119; 0121
(2018/08/28)
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- A aqueous phase catalytic cascade reaction in the synthesis of isocoumarin derivatives of the method (by machine translation)
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The invention provides a method for the aqueous phase catalytic cascade reaction in the synthesis of isocoumarin derivatives of the method, which is based on the concentration in the aqueous phase is 0.1 — 1 mol/L of ortho-halo benzoic acid 1 μM with 0.1 μM — 5 μM terminal alkyne in of 0.001 μM — 1 μM catalyst bivalent copper salt and O-phenanthrene under the catalytic action of, in 0.5 μM — 6 μM inorganic base or organic base in the presence of, in 20o C — 160 o C lower reaction 1h — 50h one pot synthesis isocoumarin derivatives. The invention is an environment-friendly, the operation is simple, cheap and safe, efficient to prepare the isocoumarin compound of the novel method, compared with the prior art, not only can be applied to a large number of functional groups, but also with simple operation, high yield, single product, convenient separation and purification, safe and cheap, small pollution and the like. (by machine translation)
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Paragraph 0027-0028; 0030
(2017/08/23)
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- Hydroiodination-Triggered Cascade Reaction with I2/PPh3/H2O: Metal-Free Access to 3-Substituted Phthalides from 2-Alkynylbenzoates
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Phthalide is an important scaffold found in several biologically active compounds. Therefore, effective methods for the synthesis of phthalides are strongly desired. Herein, we describe the metal-free synthesis of 3-substituted phthalides by the reductive hydroiodination of 2-alkynylbenzoates through an I2/PPh3/H2O-triggered cascade reaction. A variety of 3-substituted phthalides were synthesized in excellent yields by a one-pot reaction involving four processes: desilylation, hydroiodination, cyclization, and reduction.
- Kawaguchi, Shin-Ichi,Nakamura, Kentaro,Yamaguchi, Kotaro,Sato, Yuki,Gonda, Yuhei,Nishioka, Masaaki,Sonoda, Motohiro,Nomoto, Akihiro,Ogawa, Akiya
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supporting information
p. 5343 - 5346
(2017/09/06)
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- On-Water Silver(I)-Catalyzed Cycloisomerization of Acetylenic Free Amines/Amides towards 7-Azaindole/Indole/Isoquinolone Derivatives
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Silver-catalyzed on-water intramolecular cyclization of acetylenic free amines is reported, which affords 7-azaindoles in good to excellent yields. Neither strong base/acid catalysts nor N-substituted substrates are required to achieve this cycloisomerization. Hydrogen bonds between water medium and the substrates play an important role in improving chemical reactivity and regioselectivity. Furthermore, the on-water reaction is extendable to acetylenic amides for isoquinolone synthesis.
- Sun, Hongpeng,Xiao, Li,Li, Wei,Xie, Qiong,Shao, Liming
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supporting information
p. 4845 - 4852
(2017/10/06)
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- Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids to Construct Functionalized Isocoumarins
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An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C-H functionalization procedure.
- Jiang, Guangbin,Li, Jianxiao,Zhu, Chuanle,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 4440 - 4443
(2017/09/11)
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- Pd-Catalyzed/Iodide-Promoted α-Arylation of Ketones for the Regioselective Synthesis of Isocoumarins
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A variety of isocoumarins have been synthesized directly from 2-halobenzoates and ketones through a palladium-catalyzed α-arylation step followed by an intramolecular cyclization process. The addition of iodide anions to the reaction mixture increased yields and selectivities especially when 2-bromobenzoates were employed. This phosphine-free one-pot synthesis features a high functional group tolerance and gives access to richly decorated isocoumarins. This general methodology was successful in the total synthesis of Xyridin A, an important natural product with antibacterial and antifungal activity.
- Casnati, Alessandra,Maggi, Raimondo,Maestri, Giovanni,Della Ca, Nicola,Motti, Elena
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p. 8296 - 8303
(2017/08/14)
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- Copper-catalyzed annulation of 2-bromobenzoic esters with terminal alkynes towards 3-substituted isocoumarins
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An efficient method for the synthesis of 3-substituted isocoumarins that are an important class of biologically active scaffolds via annulation of 2-bromobenzoic esters with terminal alkynes by copper catalyzed is described. The advantages of this method include mild reaction conditions, high yield and regioselectivity, and wide tolerance toward functional groups.
- Sun, Mengli,Su, Lebin,Dong, Jianyu,Liu, Long,Zhou, Yongbo,Yin, Shuang-Feng
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supporting information
p. 2433 - 2437
(2017/05/31)
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- Enantioselective Synthesis of 1,2-Dihydronaphthalenes via Oxidative N-Heterocyclic Carbene Catalysis
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1,2-Dihydronaphthalenes are important molecules in both medicinal and synthetic chemistry, but methods for the catalytic asymmetric construction of this class of molecules are limited. The diastereo- and enantioselective N-heterocyclic carbene-catalyzed cascade annulation reactions using benzodiketones and enals under oxidative conditions, which afford a variety of 1,2-dihydronaphthalenes with two adjacent stereocenters in up to 99% yield, with >20:1 dr, and up to 99% ee, are reported. Furthermore, the product can be easily transformed to a series of useful compounds such as alcohol, amide, and epoxide.
- Perveen, Saima,Zhao, Zhifei,Zhang, Guoxiang,Liu, Jian,Anwar, Muhammad,Fang, Xinqiang
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supporting information
p. 2470 - 2473
(2017/05/24)
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- Palladium-catalyzed carbonylative synthesis of isocoumarins and phthalides by using phenyl formate as a carbon monoxide source
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A simple and efficient palladium-catalyzed intramolecular carbonylative synthesis of isocoumarins and phthalides from the easily available starting materials by employing phenyl formate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.
- Yuan, Qing,Chen, Zhen-Bang,Zhang, Fang-Ling,Zhu, Yong-Ming
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p. 1628 - 1635
(2017/02/23)
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- Rh(III)-catalyzed oxidative coupling of benzoic acids with geminal-substituted vinyl acetates: Synthesis of 3-substituted isocoumarins
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The Rh(III)-catalyzed C-H activation initiated cyclization of benzoic acids with electron-rich geminal-substituted vinyl acetates was described. The reaction was employed to prepare a range of 3-aryl and 3-alkyl substituted isocoumarins selectively.
- Zhang, Mingliang,Zhang, Hui-Jun,Han, Tiantian,Ruan, Wenqing,Wen, Ting-Bin
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p. 620 - 627
(2016/09/09)
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- Synthesis of isocoumarins: Rhenium complex-catalyzed cyclization of 2-ethynylbenzoic acids
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When 2-ethynylbenzoic acids were treated with a catalytic amount of a rhenium complex, such as ReCl(CO)5, 6-endo cyclization of 2-ethynylbenzoic acids proceeded with a high selectivity to give the corresponding isocoumarins in moderate to good yields.
- Umeda, Rui,Yoshikawa, Shunya,Yamashita, Kouji,Nishiyama, Yutaka
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p. 2172 - 2179
(2015/12/12)
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- Palladium catalyzed Suzuki Miyaura cross coupling of 3-chloroisochromen-1-one: Synthesis of glomellin and reticulol analogues
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A facile protocol has been developed for a series of 3-substituted isochromen-1-ones utilizing Suzuki coupling strategy. The reaction of 3-chloroisochromen-1one, 1 with different boronic acids utilizing PdCl2(PPh3)2-Ruphos catalytic system gave diversified 3-substituted isochromen-1-ones in excellent yields. The methodology has been utilized in the synthesis of glomellin and reticulol analogues.
- Kumar, Yadavalli Suneel,Dasaradhan, Changalaraya,Prabakaran, Kamalakannan,Manivel, Pitchai,Nawaz Khan, Fazlur-Rahman,Jeong, Euh Duck,Chung, Eun Hyuk
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p. 941 - 945
(2015/02/05)
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- Synthesis of isocoumarins through three-component couplings of arynes, terminal alkynes, and carbon dioxide catalyzed by an NHC-copper complex
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A copper-catalyzed multicomponent coupling reaction between in situ generated ortho-arynes, terminal alkynes, and carbon dioxide was developed to access isocoumarins in moderate to good yields. The key to this CO2-incorporating reaction was the use of a versatile N-heterocyclic carbene/copper complex that was able to catalyze multiple transformations within the three-component reaction.
- Yoo, Woo-Jin,Nguyen, Thanh V. Q.,Kobayashi, Shu
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supporting information
p. 10213 - 10217
(2015/03/31)
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- Novel one-pot synthesis of polysubstituted isocoumarins from arynes and trifluoroacetylated β-diketones
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Polysubstituted isocoumarins such as thunberginol A were synthesized by the reaction of substituted 2-(trimethylsilyl)-phenyl triflate with trifluoromethylated β-diketones in the presence of CsF. The reaction proceeded via carboncarbon bond insertion of aryne followed by intramolecular cyclization and CF3 anion extrusion. The C(..O)CF3 unit has high potential for not only the nucleophilic moiety but also a useful leaving group of CF3.
- Okuma, Kentaro,Hirano, Koki,Tanabe, Yukiko,Itoyama, Ryoichi,Miura, Atsumi,Nagahora, Noriyoshi,Shioji, Kosei
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supporting information
p. 492 - 494
(2014/04/17)
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- Regioselective one-pot synthesis of isocoumarins and phthalides from 2-iodobenzoic acids and alkynes by temperature control
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Copper-catalyzed coupling reaction of 2-iodobenzoic acids and alkynes such as terminal acetylenes, alkynyl carboxylic acids, and trimethylsilylacetylene selectively afforded isocoumarins and phthalides in the presence of cesium carbonate (Cs2CO3) and dimethyl sulfoxide (DMSO). Among the regioselective products, only the 6-endo-dig product, isocoumarin, was formed at 100 °C, and the 5-exo-dig product, phthalide, was formed as a major product at 25 °C. A variety of alkynes produced the corresponding isocoumarins and phthalides in good yields. A mechanism is suggested in which the formation of 2-alkynylbenzoic acid as an intermediate via Sonogashira-type coupling was ruled out in the reaction pathway. Copyright
- Kumar, Manian Rajesh,Irudayanathan, Francis Mariaraj,Moon, Joong Ho,Lee, Sunwoo
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p. 3221 - 3230
(2013/12/04)
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- Cu-catalyzed coupling-cyclization in PEG 400 under ultrasound: A highly selective and greener approach towards isocoumarins
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The combination of CuI-K2CO3-PEG 400 facilitated the coupling-cyclization of o-iodobenzoic acid with terminal alkynes under ultrasound, affording a greener and practical approach towards 3-substituted isocoumarins with remarkable regioselectivity. This inexpensive and Pd and ligand free methodology gave rise to various isocoumarins of potential pharmacological interest.
- Chary, R. Gangadhara,Reddy, G. Rajeshwar,Ganesh,Prasad, K. Vara,Chandra, S. K. Phani,Mukherjee, Soumita,Pal, Manojit
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p. 9641 - 9644
(2013/09/02)
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- New method for the synthesis of lactones via nickel-catalyzed isocyanides insertion
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A novel nickel catalyst for the reaction of tert-butyl isocyanide insertion was discovered. In this approach, 1,2-bis(diphenylphosphino)ethane (L3) serves as an efficient ligand, thereby allowing the preparation of lactones from (o-bromophenyl)phenylethanone derivatives. It is noteworthy that this is the first example of nickel acting as a metal catalyst in the reactions of tert-butyl isocyanide insertion. The significance of this methodology may draw many chemists attention in the field of isocyanide-incorporating reactions. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Fei, Xiang-Dong,Tang, Ting,Ge, Zhi-Yuan,Zhu, Yong-Ming
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p. 3262 - 3271
(2013/10/01)
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- Directing the regioselectivity of rhodium(I) catalysed cyclisation of 2-alkynyl benzoic acids
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Rhodium(I) dicarbonyl complexes 1-4 containing chelating N-donor ligands bis(pyrazolyl)methane (bpm), bis(imidazolyl)methane (bim), tris(pyrazolyl) toluidine (tpt) or tris(imidazolyl)methanol (tim) were investigated as catalysts for the hydroalkoxylation of alkynyl benzoic acids (5a-g). The regioselectivity of the reaction was shown to be highly dependent on the nature of the terminal alkyne substituent (R) of the alkynol substrate. It was also determined that the presence of a third uncoordinated N-donor group in complexes 3 and 4 suppressed the catalytic efficiency of these complexes, and that the selectivity of the reaction for forming either endocyclic (6) or exocyclic (7) hydroalkoxylation products was influenced by the pendant hydroxyl group present in complex 4. We used 13C NMR spectroscopy to quantify the polarity of the alkynyl benzoic acid C≡C bond and our efforts to correlate this measure of bond polarity to the observed regioselectivity of the reaction are discussed.
- Man, Bradley Y.-W.,Knuhtsen, Astrid,Page, Michael J.,Messerle, Barbara A.
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p. 248 - 252
(2013/10/22)
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- On homogeneous gold/palladium catalytic systems
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Two substrates containing an aryl iodide and an allenoate ester were prepared and the goldinduced cycloisomerisation to vinylgold(I) species and their proto-deauration as well as the intramolecular palladium-catalysed cross-coupling reactions were investigated. Switching to catalytic amounts of gold and palladium and stoichiometric amounts of silver did indeed furnish the product of a cycloisomerisation/ intramolecular cross-coupling. Control experiments revealed that silver cannot substitute for gold or palladium in these reactions, but a different palladium catalyst in a different oxidation state also afforded the cycloisomerisation/intramolecular crosscoupling products in only slightly reduced yields. By ICP analysis the palladium was shown to contain gold only at the sub-ppm level. This shows how carefully results obtained with such systems have to be interpreted. Then a series of allylic and benzylic o-alkynylbenzoates were investigated in gold-and palladium-catalysed reactions. For esters of benzyl alcohol and cinnamyl alcohol no palladium co-catalyst was needed for the conversion. All reagents were thoroughly checked for palladium traces by ICP analysis in order to thoroughly exclude a gold/palladium cocatalysis. Optimisation of the gold complex, counter ion and solvent showed that gold(I) isonitrile precatalysts and silver triflate as activator in dioxane are suitable to convert a number of substrates with aryl, alkyl and even cyclopropyl substituents. Crossover experiments proved an intermolecular allyl transfer.
- Hashmi, A. Stephen K.,Lothschuetz, Christian,Doepp, Rene,Ackermann, Martin,De Buck Becker, Janosc,Rudolph, Matthias,Scholz, Christian,Rominger, Frank
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p. 133 - 147
(2012/04/10)
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- Tandem reactions leading to benzo[c]chromen-6-ones and 3-substituted isocoumarins
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A simple and convenient protocol for the synthesis of benzo[c]chromen-6- ones and 3-substituted isocoumarins through a CuI-catalyzed tandem reaction of 2-bromobenzoates withcyclohexane-1,3-diones or acyclic 1,3-diones is developed. This strategy can also be extended to the one-pot synthesis of isoquinolin-1(2H)-one and 3,4-dihydrophenanthridine-1,6(2H,5H)-dione. A simple and convenient protocol for the synthesis of benzo[c]chromen-6-ones and 3-substituted isocoumarins through a CuI-catalyzed tandem reaction of 2-bromobenzoates with cyclohexane-1,3-dione or acyclic 1,3-dione has been developed. This strategy can also be extended to the one-pot synthesis of isoquionlin-1(2H)-one and 3,4-dihydrophenanthridine-1,6-(2H,5H)-dione. Copyright
- Fan, Xuesen,He, Yan,Cui, Liangyan,Guo, Shenghai,Wang, Jianji,Zhang, Xinying
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supporting information; experimental part
p. 673 - 677
(2012/03/10)
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- Palladium-catalyzed synthesis of isocoumarins and phthalides via tert -butyl isocyanide insertion
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A novel and highly efficient strategy for the synthesis of isocoumarins and phthalides through a palladium(0)-catalyzed reaction incorporating tert-butyl isocyanide has been developed. This process, providing one of the simplest methods for the synthesis of this class of valuable lactones, involves two steps including cyclization reaction and simple acid hydrolysis. The methodology is tolerant of a wide range of substrates and applicable to library synthesis.
- Fei, Xiang-Dong,Ge, Zhi-Yuan,Tang, Ting,Zhu, Yong-Ming,Ji, Shun-Jun
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p. 10321 - 10328
(2013/01/15)
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- Synthesis of 3-substituted isocoumarins via a cascade intramolecular Ullmann-type coupling-rearrangement process
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A simple and highly efficient strategy for the synthesis of 3-substituted isocoumarins through a copper(I)-catalyzed reaction of 1-(2-halophenyl)-1,3- diones has been developed. The procedure is based on a cascade copper-catalyzed intramolecular Ullmann-type C-arylation and rearrangement process. This methodology is tolerant of a wide range of substrates and applicable to library synthesis.
- Ge, Zhi-Yuan,Fei, Xiang-Dong,Tang, Ting,Zhu, Yong-Ming,Shen, Jing-Kang
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experimental part
p. 5736 - 5743
(2012/08/07)
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- Synthesis of isocoumarin derivatives via the copper-catalyzed tandem sequential cyclization of 2- halo-N-phenyl benzamides and acyclic 1,3-diketones
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A facile and rapid synthesis of isocoumarin derivatives using a copper-catalyzed tandem C-C/C-O coupling strategy from readily available substrates is described. The reactions of a wide range of 2-iodo-N-phenyl benzamides and acyclic diketones as starting materials were investigated.
- Kavala, Veerababurao,Wang, Cheng-Chuan,Barange, Deepak Kumar,Kuo, Chun-Wei,Lei, Po-Min,Yao, Ching-Fa
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experimental part
p. 5022 - 5029
(2012/07/16)
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- Regioselective synthesis of isochromenones by iron(III)/PhSeSePh-mediated cyclization of 2-alkynylaryl esters
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A series of 4-Se-(Te, S)-isochromenones and 3-substituted isochromenones were synthesized in good yields via FeCl3-mediated cyclization of alkynylaryl esters with different diorganyl dichalcogenides. This methodology was carried out at room temperature, using inexpensive and environmentally friendly iron salts as metallic source and under air atmosphere. The reaction showed to be tolerant to a range of substituents bonded into the aromatic ring of the diorganyl dichalcogenides as well as to alkyl groups directly bonded to the chalcogen atom. Alternatively, the cyclization reaction of 2-alkynylaryl esters with FeCl3, in the absence of diorganyl dichalcogenide, gave the isochromenones without the chalcogen moiety in the structure. This approach proved to be highly regioselective, providing only six-membered ring products, once the possible five-membered products were not observed in any experiments.
- Speranca, Adriane,Godoi, Benhur,Pinton, Simone,Back, Davi F.,Menezes, Paulo H.,Zeni, Gilson
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experimental part
p. 6789 - 6797
(2011/10/02)
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- 3-Substituted isocoumarins as thymidine phosphorylase inhibitors
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3-Substituted isocoumarins 1-19 were synthesized and evaluated for their thymidine phosphorylase inhibitory activity. Eight (8) compounds exhibited a varying degree of inhibitory activity towards thymidine phosphorylase from E. coli with IC50 values between 61- 402 μM. The activities were compared with the standard 7-deazaxanthine (IC50 = 39.28 ± 0.76 μM).
- Khan, Khalid Mohammed,Ahmed, Sumbul,Hussain, Sajjad,Ambreen, Nida,Perveen, Shahnaz,Choudhary, M. Iqbal
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experimental part
p. 265 - 268
(2011/03/18)
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- Diselenide- and disulfide-mediated synthesis of isocoumarins
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Cyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6-endo-trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization-elimination route.
- Shahzad, Sohail A.,Venin, Claire,Wirth, Thomas
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experimental part
p. 3465 - 3472
(2010/09/07)
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- Synthesis of isocoumarin via PTSA-catalyzed annulation of diarylalkynes
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p-Toluenesulfonic acid (PTSA) in ethanol was used as a mild acid catalyst for the annulation of various functionalized diarylalkynes under microwave irradiation. This metal-free process allowed the synthesis of a range of 3-aryl-substituted isocoumarins in good yields. Georg Thieme Verlag Stuttgart.
- Le Bras, Gaelle,Hamze, Abdallah,Messaoudi, Samir,Provot, Olivier,Le Calvez, Pierre-Benoit,Brion, Jean-Daniel,Alami, Mouad
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experimental part
p. 1607 - 1611
(2009/04/03)
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- Synthesis of some 3-substituted isochromen-1-ones
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An alternative method for the synthesis of 3-substituted isocoumarins from homophthalic acid and ester is described. Copyright Taylor & Francis Group, LLC.
- Tajudeen, S. Syed,Khan, F. Nawaz
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p. 3649 - 3656
(2008/03/13)
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- Organomercury Mediated Synthesis of Isocoumarins
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A facile and convenient synthesis of isocoumarins via an organomercurial route is reported.The synthesis involves reaction of methyl 2-alkynbenzoates with mercuric acetate to give the corresponding isocoumarin mercurials which serve as intermediates to afford the appropriate isocoumarins having substituents as Cl,I,Br,COCH3 etc.
- Nagarajan, A.,Balasubramanian, Tiruvenkat R.
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p. 917 - 919
(2007/10/02)
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