- Photoredox Activation of Formate Salts: Hydrocarboxylation of Alkenes via Carboxyl Group Transfer
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A photoredox activation mode of formate salts for carboxylation was developed. Using a formate salt as the reductant, carbonyl source, and hydrogen atom transfer reagent, a wide range of alkenes can be converted into acid products via a carboxyl group tra
- Huang, Yan,Hou, Jing,Zhan, Le-Wu,Zhang, Qian,Tang, Wan-Ying,Li, Bin-Dong
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p. 15004 - 15012
(2021/12/14)
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- Synthesis, crystal structure, and catalytic activity of bridged-bis(N-heterocyclic carbene) palladium(II) complexes in selective Mizoroki-Heck cross-coupling reactions
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A series of three 1,3-propanediyl bridged bis(N-heterocyclic carbene)palladium(II) complexes (Pd-BNH1, Pd-BNH2, and Pd-BNH3), with + I effect order of the N-substituents of the ligand (isopropyl > benzyl > methoxyphenyl), was the subject of a spectroscopic, structural, computational and catalytic investigation. The bis(NHC)PdBr2 complexes were evaluated in Mizoroki-Heck coupling reactions of aryl bromides with styrene or acrylate derivatives and showed high catalytic efficiency to produce diarylethenes and cinnamic acid derivatives. The X-ray structure of the most active palladium complex Pd-BNH3 shows that the Pd(II) center is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromide ligands in cis position, resulting in a distorted square planar geometry. The NMR data of Pd-BNH3 are consistent with a single chair-boat rigid conformer in solution with no dynamic behavior of the 8-membered ring palladacycle in the temperature range 25–120 °C. The catalytic activities of three Pd-bridged bis(NHC) complexes in the Mizoroki-Heck cross-coupling reactions were not found to have a direct correlation with +I effect order of the N-substituents of the ligand. However, a direct correlation was found between the DFT calculated absolute softness of the three complexes with their respective catalytic activity. The highest calculated softness, in the case of Pd-BNH3, is expected to favor the coordination steps of both the soft aryl bromides and alkenes in the Heck catalytic cycle.
- El Ali, Bassam,Fettouhi, Mohammed,Iali, Wissam,Mansour, Waseem,Suleiman, Rami
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- Method for synthesizing phenylpropionic acid compounds through heterogeneous palladium metal catalysis
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The invention discloses a method for synthesizing phenylpropionic acid compounds by heterogeneous catalysis. The method comprises the following steps: sequentially adding Pd@POL, toluene, styrene, formic acid and acetic anhydride into a reaction flask, stirring the reaction mixture at 80 DEG C to react, cooling the reaction solution to room temperature after the reaction is finished, diluting with dichloromethane, and transferring the solution into a separating funnel, washing with a sodium hydroxide solution, acidifying the water layer with a hydrochloric acid aqueous solution, extracting with dichloromethane, merging organic phases, drying with anhydrous sodium sulfate, and carrying out vacuum concentration to obtain the phenylpropionic acid compound. The method can remove heavy metal residues, is green and environment-friendly, is simple to operate and easy to implement, and the prepared phenylpropionic acid compound has a good application prospect.
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Paragraph 0047-0054
(2021/04/21)
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- Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
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A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
- Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
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p. 2080 - 2088
(2020/02/20)
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- Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
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The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
- Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
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supporting information
(2020/02/13)
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- Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?3-Lactams and Kinetic Resolution of ?3-Substituted Allenoates
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A C2-symmetric chiral phosphine catalyst, NUSIOC-Phos, which can be easily derived from cyclohexyl-fused spirobiindane, was introduced. A highly enantioselective domino process involving pyrrolidine-2,3-diones and γ-substituted allenoates catalyzed by NUSIOC-Phos has been disclosed. Diastereospecific tricyclic γ-lactams containing five contiguous stereogenic centers were obtained in high yields and with nearly perfect enantioselectivities. A kinetic resolution process of racemic γ-substituted allenoates was developed for the generation of optically enriched chiral allenoates.
- Wu, Mingyue,Han, Zhaobin,Li, Kaizhi,Wu, Ji'En,Ding, Kuiling,Lu, Yixin
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supporting information
p. 16362 - 16373
(2019/10/16)
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- Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations
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Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99:1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts. In addition, similar results were obtained for the carbonylation of secondary alcohols.
- Huang, Zijun,Cheng, Yazhe,Chen, Xipeng,Wang, Hui-Fang,Du, Chen-Xia,Li, Yuehui
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supporting information
p. 3967 - 3970
(2018/04/23)
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- Recyclable Hypervalent-Iodine-Mediated Dehydrogenative α,β′-Bifunctionalization of β-Keto Esters under Metal-Free Conditions
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We have developed a method for recyclable hypervalent-iodine-mediated direct dehydrogenative α,β′- bifunctionalization of β-ketoesters and β-diketones under metal-free conditions, which affords a straightforward way to synthesize benzo-fused 2,3-dihydrofurans. This efficient, mild method, which has a wide substrate scope and good functional-group tolerance, was used for the multistep synthesis of the protected aglycone of a naturally occurring phenolic glycoside. A mechanism involving Michael addition to an enone intermediate and subsequent oxidative cyclization is proposed.
- Duan, Ya-Nan,Cui, Li-Qian,Zuo, Lin-Hong,Zhang, Chi
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supporting information
p. 13052 - 13057
(2015/09/07)
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- Catalytic Asymmetric Reduction of a 3,4-Dihydroisoquinoline for the Large-Scale Production of Almorexant: Hydrogenation or Transfer Hydrogenation?
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Several methods are presented for the enantioselective synthesis of the tetrahydroisoquinoline core of almorexant (ACT-078573A), a dual orexin receptor antagonist. Initial clinical supplies were secured by the Noyori Ru-catalyzed asymmetric transfer hydrogenation (Ru-Noyori ATH) of the dihydroisoquinoline precursor. Both the yield and enantioselectivity eroded upon scale-up. A broad screening exercise identified TaniaPhos as ligand for the iridium-catalyzed asymmetric hydrogenation with a dedicated catalyst pretreatment protocol, culminating in the manufacture of more than 6 t of the acetate salt of the tetrahydroisoquinoline. The major cost contributor was TaniaPhos. By switching the dihydroisoquinoline substrate of the Ru-Noyori ATH to its methanesulfonate salt, the ATH was later successfully reduced to practice, delivering several hundreds of kilograms of the tetrahydroisoquinoline, thereby reducing the catalyst cost contribution significantly. The two methods are compared with regard to green and efficiency metrics.
- Verzijl, Gerard K. M.,De Vries, Andre H. M.,De Vries, Johannes G.,Kapitan, Peter,Dax, Thomas,Helms, Matthias,Nazir, Zarghun,Skranc, Wolfgang,Imboden, Christoph,Stichler, Juergen,Ward, Richard A.,Abele, Stefan,Lefort, Laurent
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p. 1531 - 1539
(2014/01/06)
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- A simple and straightforward approach toward selective C=C bond reduction by hydrazine
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A simple and straightforward method for reducing the C=C double bond with hydrazine is described. A number of representative C=C bonds in various steric and electronic environments were examined. Substituted alkenes can be selectively reduced in EtOH in the presence of hydrazine to give the corresponding products in up to 100% yields.
- Chen, Hao,Wang, Jianmin,Hong, Xuechuan,Zhou, Hai-Bing,Dong, Chune
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supporting information
p. 758 - 761
(2012/11/07)
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- Rhodium(I)-catalyzed 1,4-addition of arylboronic acids to acrylic acid in water: One-step preparation of 3-arylpropionic acids
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A practical method for the one-step preparation of 3-arylpropionic acids through rhodium-catalyzed 1,4-addition of arylboronic acids to acrylic acid is reported. The method is applicable to a broad scope of aryl boronic acids and displays a wide functional group tolerance operating in water as the optimal reaction medium. Georg Thieme Verlag Stuttgart · New York.
- Vautravers, Nicolas R.,Breit, Bernhard
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supporting information; experimental part
p. 2517 - 2520
(2011/11/12)
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- METHOD FOR OBTAINING AN OPTICALLY PURE 1,2,3,4 TETRAHYDRO-ISOQUINOLINE DERIVATIVE
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The invention relates to a method for obtaining enantiomerically enriched 6,7-dimethoxy-1-[2-(4-trifluoromethyl-phenyl)-ethyl]-1,2,3,4-tetrahydro-isoquinoline from a mixture of (R)-6,7-dimethoxy-1-[2-(4-trifluoromethyl-phenyl)-ethyl]-1,2,3,4-tetrahydro-isoquinoline and (S)-6,7-dimethoxy-1-[2-(4-trifluoromethyl-phenyl)-ethyl]-1,2,3,4-tetrahydro-isoquinoline.
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Page/Page column 23
(2010/06/20)
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- TRISUBSTITUTED 3,4-DIHYDRO-1H-ISOQUINOLIN COMPOUND, PROCESS FOR ITS PREPARATION, AND ITS USE
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The present invention relates to the compound of formula 7*acetate (see below), a process for its preparation, and its use
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Page/Page column 7-8
(2010/02/17)
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- PROCESS FOR THE PREPARATION OF AN ENANTIOMERIC TRISUBSTITUTED 3,4-DIHYDRO-ISOQUINOLINE DERIVATIVE
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The present invention relates to a process for the preparation of the compound of formula (7) which process comprises the hydrogenation of the compound of formula (4) using bis[chloro-1,5-cyclooctadiene-iridium], (S)-i-dicyclohexylphosphino-2-[(S)-α-(dime
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Page/Page column 2; 3; 8
(2010/12/29)
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- AMINE COMPOUND AND PHARMACEUTICAL USE THEREOF
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Provided is a novel amine compound represented by the following formula (I) having a superior peripheral blood lymphocyte decreasing action and superior in the immunosuppressive action, rejection suppressive action and the like, which shows decreased side effects of, for example, bradycardia and the like, or a pharmaceutically acceptable acid addition salt thereof, or a hydrate thereof, or a solvate thereof. wherein each symbol is as defined in the specification.
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Page/Page column 47-48
(2010/04/25)
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- Design, synthesis, and biological evaluation of novel diarylalkyl amides as TRPV1 antagonists
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We have developed a new class of diarylalkyl amides as novel TRPV1 antagonists. They exhibited potent 45Ca2+ uptake inhibitions in rat DRG neuron. In particular, the amide 59 was identified as a potent antagonist with IC50 of 57 nM. The synthesis and structure-activity relationship of the diarylalkyl amides are also described.
- Li, Fu-Nan,Kim, Nam-Jung,Paek, Seung-Mann,Kwon, Do-Yeon,Min, Kyung Hoon,Jeong, Yeon-Su,Kim, Sun-Young,Park, Young-Ho,Kim, Hee-Doo,Park, Hyeung-Geun,Suh, Young-Ger
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experimental part
p. 3557 - 3567
(2009/09/27)
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- PROCESS FOR THE PREPARATION OF AN ENANTIOMERIC TRISUBSTITUTED 3,4-DIHYDRO-ISOQUINOLINE DERIVATIVE
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The present invention relates to a process for the preparation of the compound of formula (7) which process comprises the hydrogenation of the compound of formula (4) using bis[chloro-1,5-cyclooctadiene-iridium], (S)-i -dicyclohexylphosphino- 2-[(S)-α-(di
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Page/Page column 6; 17
(2009/08/14)
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- TRISUBSTITUTED 3,4-DIHYDRO-1H-ISOQUINOLIN COMPOUND, PROCESS FOR ITS PREPARATION, AND ITS USE
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The present invention relates to the compound of formula (7*)acetate (see below), a process for its preparation, and its use.
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Page/Page column 6; 17
(2009/08/14)
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- 1,4-Cyclohexadiene with Pd/C as a rapid, safe transfer hydrogenation system with microwave heating
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A method for the rapid, safe hydrogenation of alkenes and deprotection of benzyl ethers and carboxybenzyl amides is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In general, the reactions are complete within five minutes at 100 °C.
- Quinn, John F.,Razzano, Dana A.,Golden, Kathryn C.,Gregg, Brian T.
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scheme or table
p. 6137 - 6140
(2009/04/05)
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- Efficient synthesis of halo indanones via chlorosulfonic acid mediated Friedel-Crafts cyclization of aryl propionic acids and their use in alkylation reactions
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Several halo indanones were synthesized from benzyl Meldrum's acid derivatives in two steps. Although several Lewis acids are effective for the Friedel-Crafts ring-closing reaction on more electron-rich arenes, in the case of the electron-deficient arenes this chemistry is not efficient. Here it is reported that chlorosulfonic acid (used as solvent) is an efficient reagent for cyclization of electron-withdrawing arenes. These molecules are potentially useful for subsequent alkylation reactions. The selective alkylation of 5,7-dibromo indanone is demonstrated using Pd-catalyzed Grignard coupling to provide monoalkylated indanone in good yield.
- Sharma, Anil K.,Subramani, Amutha V.,Gorman, Christopher B.
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p. 389 - 395
(2007/10/03)
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- Direct synthesis of 3-arylpropionic acids by tetraphosphine/palladium catalysed Heck reactions of aryl halides with acrolein ethylene acetal
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Through the use of [PdCl(C3H5)]2/Cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides undergoes Heck reaction with acrolein ethylene acetal. With this acetal, the selective formation of 3-arylpropionic acids/esters was observed. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. Graphical Abstract.
- Lemhadri, Mhamed,Doucet, Henri,Santelli, Maurice
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p. 11533 - 11540
(2007/10/03)
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- Synthesis and in vitro evaluation of human FP-receptor selective prostaglandin analogues
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The in vitro evaluation of a series of saturated prostaglandins revealed that compounds with omega chin aromatic rings retain nanomolar potency for the human prostaglandin F receptor (hFP receptor), exemplified by compound 8. In contrast, the double bonds are required for activity in the series with an acyclic omega chain as in PGF(2α). (C) 2000 Published by Elsevier Science Ltd.
- DeLong, Mitchell A.,Amburgey, Jack,Taylor, Cynthia,Wos, John A.,Soper, David L.,Wang, Yili,Hicks, Renee
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p. 1519 - 1522
(2007/10/03)
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