- A cross-linked reverse micelle-encapsulated palladium catalyst
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Cross-linked reverse micelle-palladium catalysts are effective and stable cross-coupling catalysts; cross-linking is crucial for stability. The Royal Society of Chemistry 2005.
- Price, Kristin E.,McQuade, D. Tyler
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- Phosphine-Functionalized Chitosan Microparticles as Support Materials for Palladium Nanoparticles in Heck Reactions
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Herein, we investigated the activation and stabilization of Pd nanoparticles using microparticles of chitosan-functionalized with phosphine moieties. The catalytic activity of the prepared material was assessed in a series of Heck reactions, which demonst
- Biajoli, André F. P.,Fajardo, André R.,Lemos, Thalia S. A.,de Souza, Jaqueline F.
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- Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction
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A new C(sp3)?H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C?C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
- Carlet, Federica,Bertarini, Greta,Broggini, Gianluigi,Pradal, Alexandre,Poli, Giovanni
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supporting information
p. 2162 - 2168
(2021/04/02)
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- Mizoroki-Heck Reaction of Unstrained Aryl Ketones via Ligand-Promoted C-C Bond Olefination
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Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.
- Wang, Mei-Ling,Xu, Hui,Li, Han-Yuan,Ma, Biao,Wang, Zhen-Yu,Wang, Xing,Dai, Hui-Xiong
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supporting information
p. 2147 - 2152
(2021/04/05)
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- Reduction of Electron-Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
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Direct hydrogen atom transfer from a photoredox-generated Hantzsch ester radical cation to electron-deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT-driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron-donating or electron-withdrawing substituents in the aromatic ring and with good functional group compatibility. (Figure presented.).
- Larionova, Natalia A.,Ondozabal, Jun Miyatake,Cambeiro, Xacobe C.
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supporting information
p. 558 - 564
(2020/12/07)
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- A Photocatalytic Regioselective Direct Hydroaminoalkylation of Aryl-Substituted Alkenes with Amines
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A photocatalytic method for the α-selective hydroaminoalkylation of cinnamate esters has been developed. The reaction involves the regioselective addition of α-aminoalkyl radicals generated from aniline derivatives or aliphatic amines to the α-position of unsaturated esters. The scope of aromatic alkenes was extended to styrenes undergoing hydroaminoalkylation with anti-Markovnikov selectivity, which confirms the importance of the aromatic group at the β-position. Simple scale-up is demonstrated under continuous flow conditions, highlighting the practicality of the method.
- Larionova, Natalia A.,Ondozabal, Jun Miyatake,Smith, Emily G.,Cambeiro, Xacobe C.
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supporting information
p. 5383 - 5388
(2021/07/26)
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- Design and synthesis of bitopic 2-phenylcyclopropylmethylamine (pcpma) derivatives as selective dopamine d3 receptor ligands
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2-Phenylcyclopropylmethylamine (PCPMA) analogues have been reported as selective serotonin 2C agonists. On the basis of the same scaffold, we designed and synthesized a series of bitopic derivatives as dopamine D3R ligands. A number of these new compounds show a high binding affinity for D3R with excellent selectivity. Compound (1R,2R)-22e and its enantiomer (1S,2S)-22e show a comparable binding affinity for the D3R, but the former is a potent D3R agonist, while the latter acts as an antagonist. Molecular docking studies revealed different binding poses of the PCPMA moiety within the orthosteric binding pocket of the D3R, which might explain the different functional profiles of the enantiomers. Compound (1R,2R)-30q shows a high binding affinity for the D3R (Ki = 2.2 nM) along with good selectivity, as well as good bioavailability and brain penetration properties in mice. These results reveal that the PCPMA scaffold may serve as a privileged scaffold for the design of aminergic GPCR ligands.
- Tan, Liang,Zhou, Qingtong,Yan, Wenzhong,Sun, Jian,Kozikowski, Alan P.,Zhao, Suwen,Huang, Xi-Ping,Cheng, Jianjun
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p. 4579 - 4602
(2020/06/08)
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- Enantioenriched Methylene-Bridged Benzazocanes Synthesis by Organocatalytic and Superacid Activations
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Achieving in a straightforward way the synthesis of enantioenriched elaborated three-dimensional molecules related to bioactive natural products remains a long-standing quest in organic synthesis. Enantioselective organocatalysis potentially offers a uniq
- Beaud, Rodolphe,Michelet, Bastien,Reviriot, Yasmin,Martin-Mingot, Agnès,Rodriguez, Jean,Bonne, Damien,Thibaudeau, Sébastien
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supporting information
p. 1279 - 1285
(2019/12/24)
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- Synthesis and biological evaluation of celastrol derivatives as anti-ovarian cancer stem cell agents
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Ovarian cancer is associated with a high percentage of recurrence of tumors and resistance to chemotherapy. Cancer stem cells (CSCs) are responsible for cancer progression, tumor recurrence, metastasis, and chemoresistance. Thus, developing CSC-targeting therapy is an urgent need in cancer research and clinical application. In an attempt to achieve potent and selective anti-CSC agents, a series of celastrol derivatives with cinnamamide chains were synthesized and evaluated for their anti-ovarian cancer activities. Most of the compounds exhibited stronger antiproliferative activity than celastrol, and celastrol derivative 7g with a 3,4,5-trimethoxycinnamamide side chain was found to be the most potent antiproliferative agent against ovarian cancer cells with an IC50 value of 0.6 μM. Additionally, compound 7g significantly inhibited the colony formation ability and reduced the number of tumor spheres. Furthermore, compound 7g decreased the percentage of CD44+, CD133+ and ALDH+ cells. Thus, compound 7g is a promising anti-CSC agent and could serve as a candidate for the development of new anti-ovarian cancer drugs.
- Li, Xiaojing,Ding, Jie,Li, Ning,Liu, Wenxia,Ding,Zheng, Huijuan,Ning, Yanyan,Wang, Hongmin,Liu, Renmin,Ren, Shaoda
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p. 667 - 679
(2019/07/05)
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- Discovery of 3,4,6-Trisubstituted Piperidine Derivatives as Orally Active, Low hERG Blocking Akt Inhibitors via Conformational Restriction and Structure-Based Design
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A series of 3,4-disubstituted piperidine derivatives were obtained based on a conformational restriction strategy and a lead compound, A12, that exhibited potent in vitro and in vivo antitumor efficacies; however, obvious safety issues limited its further development. Thus, systematic exploration of the structure-activity relationship of compound A12, involving the phenyl group, hinge-linkage, and piperidine moiety, led to the discovery of the superior 3,4,6-trisubstituted piperidine derivative E22. E22 showed increased potency in Akt1 and cancer cell inhibition, remarkably reduced human ether-a-go-go-related gene blockage, and significantly improved safety profiles. Compound E22 also exhibited good kinase selectivity, had a good pharmacokinetic profile, and displayed very potent in vivo antitumor efficacy, with over 90% tumor growth inhibition in the SKOV3 xenograft model. Further mechanistic studies were conducted to demonstrate that compound E22 could significantly inhibit the phosphorylation of proteins downstream of Akt kinase in cells and tumor tissue from the xenograft model.
- Dong, Xiaowu,Zhan, Wenhu,Zhao, Mengting,Che, Jinxin,Dai, Xiaoyang,Wu, Yizhe,Xu, Lei,Zhou, Yubo,Zhao, Yanmei,Tian, Tian,Cheng, Gang,Jin, Zegao,Li, Jia,Shao, Yanfei,He, Qiaojun,Yang, Bo,Weng, Qinjie,Hu, Yongzhou
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supporting information
p. 7264 - 7288
(2019/08/20)
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- 4-Aryl Pyrrolidines as a Novel Class of Orally Efficacious Antimalarial Agents. Part 1: Evaluation of 4-Aryl- N-benzylpyrrolidine-3-carboxamides
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Identification of novel chemotypes with antimalarial efficacy is imperative to combat the rise of Plasmodium species resistant to current antimalarial drugs. We have used a hybrid target-phenotype approach to identify and evaluate novel chemotypes for malaria. In our search for drug-like aspartic protease inhibitors in publicly available phenotypic antimalarial databases, we identified GNF-Pf-4691, a 4-aryl-N-benzylpyrrolidine-3-carboxamide, as having a structure reminiscent of known inhibitors of aspartic proteases. Extensive profiling of the two terminal aryl rings revealed a structure-activity relationship in which relatively few substituents are tolerated at the benzylic position, but the 3-aryl position tolerates a range of hydrophobic groups and some heterocycles. Out of this effort, we identified (+)-54b (CWHM-1008) as a lead compound. 54b has EC50 values of 46 and 21 nM against drug-sensitive Plasmodium falciparum 3D7 and drug-resistant Dd2 strains, respectively. Furthermore, 54b has a long half-life in mice (4.4 h) and is orally efficacious in a mouse model of malaria (qd; ED99 ~ 30 mg/kg/day). Thus, the 4-aryl-N-benzylpyrrolidine-3-carboxamide chemotype is a promising novel chemotype for malaria drug discovery.
- Meyers, Marvin J.,Liu, Jianguang,Xu, Jing,Leng, Fang,Guan, Jiantong,Liu, Zhijun,McNitt, Sarah A.,Qin, Limei,Dai, Linglin,Ma, Hongwei,Adah, Dickson,Zhao, Siting,Li, Xiaofen,Polino, Alex J.,Nasamu, Armiyaw S.,Goldberg, Daniel E.,Liu, Xiaorong,Lu, Yongzhi,Tu, Zhengchao,Chen, Xiaoping,Tortorella, Micky D.
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supporting information
p. 3503 - 3512
(2019/03/29)
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- Synthesis and Catalytic Applications of [N,N]-Pyrrole Ligands for the Regioselective Synthesis of Styrene Derivatives
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We report the synthesis of two [N,N]-donor ligands (5 a–b) containing a 2-chalcogenazoline as the structural motif. These compounds were synthesized from a common intermediate Fischer type aminocarbene complex (3). The palladium-complexes of these [N,N]-donor ligands were successfully used as catalytic precursors in the Mizoroki-Heck coupling reaction between aryl halides and methyl acrylate, styrene and ethylene. For methyl acrylates, high yields with TOF values between 0.6 and 5.5×105 h?1 were obtained. In the case of ethylene, we reached high regioselectivities to obtain a diversity of styrene derivatives under soft pressure conditions, with good values of TON and TOF. (Figure presented.).
- Hochberger-Roa, Frank,Cortés-Mendoza, Salvador,Gallardo-Rosas, David,Toscano, Ruben A.,Ortega-Alfaro, M. Carmen,López-Cortés, José G.
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supporting information
p. 4055 - 4064
(2019/07/31)
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- A Bipyridine-Palladium Derivative as General Pre-Catalyst for Cross-Coupling Reactions in Deep Eutectic Solvents
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A versatile and DES-compatible bipyridine palladium complex has been developed as a general pre-catalyst for different cross-coupling reactions (Hiyama, Suzuki-Miyaura, Heck-Mizoroki and Sonogashira) in deep eutectic solvents. Hydrogen bond capacity of the ligand allows to keep the excellent level of results previously obtained in classical organic solvents. Palladium pre-catalyst showed a high catalytic activity for many cross-coupling reactions, demonstrating a great versatility and applicability. Also, this methodology employs sustainable solvents as a reaction medium and highlights the potential of DES as alternative solvents in organometallic catalysis. The catalyst and DES were easily and successfully recycled. The formation of PdNPs in DES has been confirmed by TEM and XPS analysis and their role as catalyst by mercury test. The dynamic coordination of bipyridine-type ligand in the palladium complex formation has been studied via UV/Vis. (Figure presented.).
- Saavedra, Beatriz,González-Gallardo, Nerea,Meli, Alessandro,Ramón, Diego J.
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supporting information
p. 3868 - 3879
(2019/07/12)
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- Linear polystyrene-stabilized Rh(III) nanoparticles for oxidative coupling of arylboronic acids with alkenes in water
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Linear polystyrene-stabilized Rh(III) nanoparticles (PS-Rh(III)NPs) were obtained when an aqueous solution of RhCl3 was stirred at 90 °C in the presence of KOH, 4-methylphenylboronic acid, and linear polystyrene, as indicated by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). PS-Rh(III)NPs exhibited high catalytic activity for the oxidative coupling of arylboronic acids with alkenes. In contrast, PS-Rh(0)NPs prepared with NaBH4 had little activity for the same reaction.
- Ohtaka, Atsushi,Fukui, Shiho,Sakon, Akira,Hamasaka, Go,Uozumi, Yasuhiro,Shinagawa, Tsutomu,Shimomura, Osamu,Nomura, Ry?ki
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- Dimethylisosorbide (DMI) as a Bio-Derived Solvent for Pd-Catalyzed Cross-Coupling Reactions
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Palladium-catalyzed bond-forming reactions, such as the ?-Suzuki-Miyaura and Mizoroki-Heck reactions, are some of the most broadly utilized reactions within the chemical industry. These reactions frequently employ hazardous solvents; however, to adhere to increasing sustainability pressures and restrictions regarding the use of such solvents, alternatives are highly sought after. Here we demonstrate the utility of dimethyl isosorbide (DMI) as a bio-derived solvent in several benchmark Pd-catalyzed reactions: Suzuki-Miyaura (13 examples, 62-100% yield), Mizoroki-Heck (13 examples, 47-91% yield), and Sonogashira (12 examples, 65-98% yield).
- Wilson, Kirsty L.,Murray, Jane,Sneddon, Helen F.,Jamieson, Craig,Watson, Allan J. B.
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p. 2293 - 2297
(2018/10/20)
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- Synthesis of olefins via a Wittig reaction mediated by triphenylarsine
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An arsine-mediated Wittig reaction for the synthesis of olefins is described. After heating triphenylarsine in the presence of an activated alkyl bromide for 30?min, the resulting arsonium salt condensed with aldehydes in as little as 5?min at room temperature, yielding the olefins in high yields. Aromatic, heteroaromatic, and alkyl aldehydes were all suitable substrates for this process.
- Li, Lun,Stimac, Jared C.,Geary, Laina M.
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supporting information
p. 1379 - 1381
(2017/03/17)
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- Diastereoselective Synthesis of trans-2,3-Diaryl(heteroaryl)-3,6-dihydropyrans by an Allylboration/Ring-Closing-Metathesis Sequence
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trans-2,3-Diaryl(heteroaryl)-dihydropyrans were synthesized by an allylboration/ring-closing-metathesis sequence, using allylboranes formed in situ from the corresponding allylic alcohols. Aryl(heteroaryl) substituents were thus installed diastereoselectively onto dihydropyran rings in a trans fashion. These disubstituted dihydropyrans were further transformed into monosaccharide-like tetrahydropyrans.
- Nocquet, Pierre-Antoine,Corbu, Andrei,Meerpoel, Lieven,Stansfield, Ian,Berthelot, Didier,Angibaud, Patrick,Cossy, Janine
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supporting information
p. 3343 - 3354
(2017/06/29)
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- Oxidative coupling of Michael acceptors with aryl nucleophiles produced through rhodium-catalyzed C-C bond activation
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Utilizing rhodium catalysis, aryl nucleophiles generated via carbon-carbon single bond activation successfully undergo oxidative coupling with Michael acceptors. The reaction scope encompasses a broad range of nucleophiles generated from quinolinyl ketones as well as a series of electron deficient terminal alkenes, illustrating the broad potential of intersecting carbon-carbon bond activation with synthetically useful coupling methodologies. The demonstrated oxidative coupling produces a range of cinnamyl derivatives, several of which are challenging to prepare via conventional routes.
- Gregerson, Caroline E.,Trentadue, Kathryn N.,Phipps, Erik J. T.,Kirsch, Janelle K.,Reed, Katherine M.,Dyke, Gabriella D.,Jansen, Jacob H.,Otteman, Christian B.,Stachowski, Jessica L.,Johnson, Jeffrey B.
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p. 5944 - 5948
(2017/07/25)
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- Arylhydrazones Derivatives Containing a Benzothiazole Moiety, Efficient Ligands in the Palladium-Catalyzed Mizoroki–Heck and Suzuki–Miyaura Cross-coupling Reactions under IR Irradiation
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A simple arylhydrazone containing the benzothiazole moiety which may be used as an efficient ligand in the palladium-catalyzed Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions, under infrared irradiation as an alternative source of energy, is presented. The reactions proceeded with extremely high efficiency under mild conditions and produced very good yields.
- Ortega-Jiménez, Fernando,Penieres-Carrillo, José Guillermo,López-Cortés, José Guadalupe,Carmen Ortega-Alfaro,Lagunas-Rivera, Selene
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p. 1881 - 1888
(2017/09/12)
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- A kind of carboxylic acid with malonic acid method of esterification reaction of dimethyl ester (by machine translation)
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The invention belongs to the field of chemical synthesis and particularly relates to a carboxyl acid compound methyl etherification method. The carboxyl acid compound methyl etherification method comprises the following steps: in a polar solvent, using a carboxyl acid compound and dimethyl malonate as reactants, under the catalysis of a catalyst, and preparing an acid methyl ester compound through the methyl etherification reaction of the carboxyl acid. The method has the advantages of cheap raw materials, easiness in raw material acquisition, low toxicity, high safety, simple neutral salt catalyst and low dosage and is suitable for industrial application.
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Paragraph 0062; 0063
(2017/02/28)
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- Infrared irradiation or microwave assisted cross-coupling reactions using sulfur-containing ferrocenyl-palladacycles
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The synthesis of four new sulfur-containing palladacycles 3a-d [FcC(S)OEtPdClZR3, where: 3a, ZR3: PPh3; 3b, ZR3: P(o-Tol)3; 3c, ZR3: PMe3; 3d, ZR3: SbPh3] from ferrocenyl thionoester 1 [FcC(S)OEt] in good yields is reported. The catalytic applications of these cyclopalladated complexes in Heck and Suzuki cross-coupling reactions were also evaluated, in combination with infrared or microwave as energy sources. The coupled products of these reactions were obtained in good to excellent yields, short reaction times and low catalyst loading.
- Balam-Villarreal,Sandoval-Chávez,Ortega-Jiménez,Toscano,Carreón-Castro,López-Cortés,Ortega-Alfaro
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- Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination
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A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner-Wadsworth-Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in situ. Subsequent deprotonative metalation of phosphonate esters followed by HWE with aldehydes furnishes enoates. This operationally convenient, mechanistically unique protocol converts the traditionally challenging aryl, alkenyl, and alkynyl esters to homologated enoates at room temperature within a single vessel.
- Dakarapu, Udaya Sree,Bokka, Apparao,Asgari, Parham,Trog, Gabriela,Hua, Yuanda,Nguyen, Hiep H.,Rahman, Nawal,Jeon, Junha
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supporting information
p. 5792 - 5795
(2015/12/11)
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- Selenium-catalyzed C(sp3)-H acyloxylation: Application in the expedient synthesis of isobenzofuranones
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Oxidative Se-catalyzed C(sp3)-H bond acyloxylation has been used to construct a diverse array of isobenzofuranones from simple ortho-allyl benzoic acid derivatives. The synthetic procedure employs mild reaction conditions and gives high chemoselectivity enabled by an inexpensive organodiselane catalyst. The presented approach offers a new synthetic pathway toward the core structures of phthalide natural products.
- Kr?tzschmar, Felix,Kassel, Martin,Delony, Daniel,Breder, Alexander
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supporting information
p. 7030 - 7034
(2015/05/05)
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- An Abnormal N-Heterocyclic Carbene-Based Palladium Dimer: Aqueous Oxidative Heck Coupling under Ambient Temperature
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Herein we report the synthesis of a new abnormal N-heterocyclic carbene (aNHC)-based ligand and its use in synthesizing an acetate bridged C-H activated palladium dimer (1). In complex 1, the carbene ligand displays an abnormal mode of binding with the palladium(II) ion. We used complex 1 as a catalyst for the oxidative Heck coupling reaction of arylboronic acids with electron-deficient as well as electron-rich olefins at ambient temperature in water to produce selectively the β-arylated products in good to excellent yields.
- Hota, Pradip Kumar,Vijaykumar, Gonela,Pariyar, Anand,Sau, Samaresh Chandra,Sen, Tamal K.,Mandal, Swadhin K.
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supporting information
p. 3162 - 3170
(2015/11/03)
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- A practical, chemoselective approach to O-methylation of carboxylic acids with dimethyl malonate
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A practical and chemoselective method is described for the O-methylation of carboxylic acids. Dimethyl malonate, a low toxic and commercially available compound was found to be an effective methylating reagent for a variety of carboxylic acids affording methyl ester products in good to high yields and with excellent chemoselectivity, without the use of strong bases as additives. A mechanism involving the utilization of potassium bromide is tentatively proposed.
- Mao, Jincheng,Liu, Defu,Li, Yongming,Zhao, Jinzhou,Rong, Guangwei,Yan, Hong,Zhang, Guoqi
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p. 9067 - 9072
(2015/11/09)
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- METHODS OF TREATMENT USING ARYLCYCLOPROPYLAMINE COMPOUNDS
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Described herein are methods of treating breast cancer using arylcyclopropylamine compounds.
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Paragraph 0298-0299
(2014/12/09)
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- Synthesis of [N,P] ligands based on pyrrole. Application to the total synthesis of arnottin i
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This paper describes the synthesis of a new class of [N,P] ligands based on pyrrole with a dimethylamino group as hard donor and a phosphine moiety as soft base. We have also modified the phosphine fragment to change the electronic and steric properties of these ligands. Palladium complex 3a proved to be very efficient in Heck cross-coupling reactions and in intramolecular aryl-aryl couplings of esters and amides. We have demonstrated the applicability and efficiency of this novel catalyst in the total synthesis of the natural product arnottin I.
- Suárez-Meneses, Jesús V.,Bonilla-Reyes, Edgar,Blé-González, Ever A.,Ortega-Alfaro, M. Carmen,Toscano, Rubén Alfredo,Cordero-Vargas, Alejandro,López-Cortés, José G.
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supporting information
p. 1422 - 1430
(2014/02/14)
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- Part I: The development of the catalytic wittig reaction
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We have developed the first catalytic (in phosphane) Wittig reaction (CWR). The utilization of an organosilane was pivotal for success as it allowed for the chemoselective reduction of a phosphane oxide. Protocol optimization evaluated the phosphane oxide precatalyst structure, loading, organosilane, temperature, solvent, and base. These studies demonstrated that to maintain viable catalytic performance it was necessary to employ cyclic phosphane oxide precatalysts of type 1. Initial substrate studies utilized sodium carbonate as a base, and further experimentation identified N,N-diisopropylethylamine (DIPEA) as a soluble alternative. The use of DIPEA improved the ease of use, broadened the substrate scope, and decreased the precatalyst loading. The optimized protocols were compatible with alkyl, aryl, and heterocyclic (furyl, indolyl, pyridyl, pyrrolyl, and thienyl) aldehydes to produce both di- and trisubstituted olefins in moderate-to-high yields (60-96 %) by using a precatalyst loading of 4-10 mol %. Kinetic E/Z selectivity was generally 66:34; complete E selectivity for disubstituted α,β-unsaturated products was achieved through a phosphane-mediated isomerization event. The CWR was applied to the synthesis of 54, a known precursor to the anti-Alzheimer drug donepezil hydrochloride, on a multigram scale (12.2 g, 74 % yield). In addition, to our knowledge, the described CWR is the only transition-/heavy-metal-free catalytic olefination process, excluding proton-catalyzed elimination reactions. A point of difference: By utilizing an organosilane to chemoselectively reduce a phosphane oxide precatalyst to a phosphane (see scheme), the first catalytic (in phosphane) Wittig reaction has been developed. The methodology has been applied to the synthesis of 22 disubstituted and 24 trisubstituted olefins, including a multigram synthesis of a precursor to the anti-Alzheimer drug donepezil hydrochloride.
- O'Brien, Christopher J.,Nixon, Zachary S.,Holohan, Andrew J.,Kunkel, Stephen R.,Tellez, Jennifer L.,Doonan, Bryan J.,Coyle, Emma E.,Lavigne, Florie,Kang, Lauren J.,Przeworski, Katherine C.
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supporting information
p. 15281 - 15289
(2013/11/06)
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- METHODS OF TREATMENT USING ARYLCYCLOPROPYLAMINE COMPOUNDS
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Described herein are methods of treating Parkinson's disease using arylcyclopropylamine compounds.
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Paragraph 0215; 0216; 0217
(2013/07/19)
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- Discovery of novel 5,5-diarylpentadienamides as orally available transient receptor potential vanilloid 1 (TRPV1) antagonists
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We have developed a novel and potent chemical series of 5,5-diphenylpentadienamides for targeting TRPV1 in vitro and in vivo. In this investigation, we examined a variety of replacements for the 5-position of dienamides with the goal of addressing issues related to pharmacokinetics. Our data suggest that substitution with alkoxy groups on the phenyl ring at the 5-position increases their ability to penetrate the blood-brain barrier. This investigation culminated in the discovery of compound (R)-36b, which showed a good pharmacokinetic profile. In vivo, compound (R)-36b was found to be effective at reversing mechanical allodynia in rats in a dose-dependent manner, and it reversed thermal hyperalgesia in a model of neuropathic pain induced by sciatic nerve injury.
- Saku, Osamu,Ishida, Hiroshi,Atsumi, Eri,Sugimoto, Yoshiyuki,Kodaira, Hiroshi,Kato, Yoshimitsu,Shirakura, Shiro,Nakasato, Yoshisuke
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experimental part
p. 3436 - 3451
(2012/06/04)
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- Pd-catalyzed sequential C-C bond formation and cleavage: Evidence for an unexpected generation of arylpalladium(II) species
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A Pd(II)-catalyzed reaction engaging alkenyl β-keto esters is reported that leads to the formation of 1-naphthols and an unexpected generation of arylpalladium(II) species. Interception of the in situ generated arylpalladium(II) species in a Mizoroki-Heck reaction, together with additional mechanistic studies, provided strong evidence in support of the first aromatization-driven β-carbon elimination process. A single Pd catalyst served to promote a series of both C-C bond forming and cleavage events in an unprecedented manner.
- Youn, So Won,Kim, Byung Seok,Jagdale, Arun R.
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supporting information; experimental part
p. 11308 - 11311
(2012/08/28)
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- Regioselective hydroformylation of allylic alcohols
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A highly regioselective hydroformylation of allylic alcohols is reported toward the synthesis of β-hydroxy-acid and aldehyde products. The selectivity is achieved through the use of a ligand that reversibly binds to alcohols in situ, allowing for a directed hydroformylation to occur. The application to trisubstituted olefins was also demonstrated, which yields a single diastereomer product consistent with a stereospecific addition of CO and hydrogen.
- Lightburn, Thomas E.,De Paolis, Omar A.,Cheng, Ka H.,Tan, Kian L.
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supporting information; experimental part
p. 2686 - 2689
(2011/06/28)
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- Emission wavelength prediction of a full-color-tunable fluorescent core skeleton, 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one
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In this paper we report on a novel fluorescent core skeleton, 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one, which we named Seoul-Fluor, having tunable and predictable photophysical properties. Using a concise and practical one-pot synthetic procedure, a 68-member library of new fluorescent compounds was synthesized with diverse substituents. In Seoul-Fluor, the electronic characteristics of the substituents, as well as their positional changes, have a close correlation with their photophysical properties. The systematic perturbation of electronic densities on the specific positions of Seoul-Fluor, guided with the Hammett constant, allows emission wavelength tunability covering the full color range. On the basis of these observations and a computational analysis, we extracted a simple first-order correlation of photophysical properties with the theoretical calculation and accurately predicted the emission wavelength of Seoul-Fluors through the rational design. In this study, we clearly demonstrate that Seoul-Fluor can provide a powerful gateway for the generation of desired fluorescent probes without the need for a tiresome synthesis and trial-and-error process.
- Kim, Eunha,Koh, Minseob,Lim, Byung Joon,Park, Seung Bum
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supporting information; experimental part
p. 6642 - 6649
(2011/06/19)
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- α,β-Unsaturated acyl azoliums from N-heterocyclic carbene catalyzed reactions: Observation and mechanistic investigation
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Caught in the act: Acyl azoliums have long been thought to be key reactive intermediates in N-heterocyclic carbene catalysis, but they have never been observed under catalytic conditions. Now, this has been successfully achieved by the characterization of α,β-unsaturated acyl azoliums (see scheme) using different spectroscopic techniques. Kinetic studies revealed the origin of their unexpected chemoselectivity in acylation and annulation reactions.
- Mahatthananchai, Jessada,Zheng, Pinguan,Bode, Jeffrey W.
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supporting information; experimental part
p. 1673 - 1677
(2011/04/21)
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- Pd-catalyzed enantioselective allyl-allyl cross-coupling
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The Pd-catalyzed cross-coupling of allylic carbonates and allylB(pin) is described. The regioselectivity of this reaction is sensitive to the bite angle of the ligand, with small-bite-angle ligands favoring the branched substitution product. This mode of
- Zhang, Ping,Brozek, Laura A.,Morken, James P.
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supporting information; scheme or table
p. 10686 - 10688
(2010/11/04)
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- PYRROLIDINE CARBOXAMIDE COMPOUNDS
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Pyrrolidine carboxamide compounds are provided. Some such pyrrolidine carboxamide compounds include agonists of sst4 which may be useful for the treatment and prevention of pain and inflammatory disorders.
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Page/Page column 30
(2010/07/10)
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- CATALYTIC WITTIG AND MITSUNOBU REACTIONS
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A catalytic Wittig method utilizing a phosphine including the steps of providing a phosphine oxide precatalyst and reducing the phosphine oxide precatalyst to produce the phosphine; forming a phosphonium ylide precursor from the phosphine and a reactant; generating a phosphonium ylide from the phosphonium ylide precursor; reacting the phosphonium yiide precursor with the aldehyde, ketone, or ester to form the olefin and the phosphine oxide which then reenters the cycle. The invention is also directed to a Mitsunobu reaction catalytic in phosphine.
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Page/Page column 16
(2010/11/03)
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- Structure-activity relationships of phenylpropanoids as antifeedants for the pine weevil Hylobius abietis
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Ethyl cinnamate has been isolated from the bark of Pinus contorta in the search for antifeedants for the pine weevil, Hylobius abietis. Based on this lead compound, a number of structurally related compounds were synthesized and tested. The usability of the Topliss scheme, a flow diagram previously used in numerous structure-activity relationship (SAR) studies, was evaluated in an attempt to find the most potent antifeedants. The scheme was initially followed stepwise; subsequently, all compounds found in the scheme were compared. In total, 51 phenylpropanoids were tested and analyzed for SARs by using arguments from the field of medicinal chemistry (rational drug design). Individual Hansch parameters based on hydrophobicity, steric, and electronic properties were examined. The effects of position and numbers of substituents on the aromatic ring, the effects of conjugation in the molecules, and the effects of the properties of the parent alcohol part of the esters were also evaluated. It proved difficult to find strong SARs derived from single physicochemical descriptors, but our study led to numerous new, potent, phenylpropanoid antifeedants for the pine weevil. Among the most potent were methyl 3-phenylpropanoates monosubstituted with chloro, fluoro, or methyl groups and the 3,4-dichlorinated methyl 3-phenylpropanoate.
- Bohman,Nordlander,Nordenhem,Sunnerheim,Borg-Karlson,Unelius
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p. 339 - 352
(2008/09/18)
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- Facile synthesis of substituted trans-2-arylcyclopropylamine inhibitors of the human histone demethylase LSD1 and monoamine oxidases A and B
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A facile synthetic route to substituted trans-2-arylcyclopropylamines was developed to provide access to mechanism-based inhibitors of the human flavoenzyme oxidase lysine-specific histone demethylase LSD1 and related enzyme family members such as monoamine oxidases A and B.
- Gooden, David M.,Schmidt, Dawn M.Z.,Pollock, Julie A.,Kabadi, Ami M.,McCafferty, Dewey G.
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p. 3047 - 3051
(2008/12/23)
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- Quantitative structure-activity relationships of pine weevil antifeedants, a multivariate approach
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Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abietis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active antifeedants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeedant activity.
- Sunnerheim, Kerstin,Nordqvist, Anneli,Nordlander, Goeran,Borg-Karlson, Anna-Karin,Unelius, C. Rickard,Bohman, Bjoern,Nordenhem, Henrik,Hellqvist, Claes,Karlen, Anders
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p. 9365 - 9372
(2008/03/17)
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- Diastereoselective method of preparing olefins by means of the horner-wadsworthemmons reaction, comprising the addition of a tris-(polyoxaalkyl)-amine sequestering agent
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The invention relates to a process for the diastereoselective preparation of olefins via the Homer-Wadsworth-Emmons reaction, which consists in reacting at low temperature a phosphonate with a carbonyl derivative in the presence of a base in a suitable solvent, characterized in that a tris(polyoxaalkyl)amine sequestering reagent of formula (I): N—[CHR1—CHR2—O—(CHR3—CHR4—O)n—R5]3 (I), wherein: n is an integer between 0 and 10; R1, R2, R3 and R4 may be identical or different, and represent a hydrogen atom or an alkyl radical containing from 1 to 4 carbon atoms; R5 represents a hydrogen atom, an alkyl or cycloalkyl radical containing up to 12 carbon atoms, a phenyl radical or a radical of formula —CμH2μ-Φ, or CmH2m+1-Φ-, with m being an integer between 1 and 12 and Φ being a phenyl radical; is added in an amount that is sufficient to increase the diastereoselectivity of the olefin.
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Page/Page column 5-6
(2010/11/08)
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- Intermolecular rhodium-catalyzed carbometalation/Heck-type reaction in water
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(Chemical Equation Presented) Only in water: A fully intermolecular rhodium-catalyzed domino coupling reaction, in which aryl boronic acids react with alkynes and acrylates to afford substituted 1,3-dienes, can only be successfully carried out in water. The reaction predominantly provides 1,4-addition products in aqueous THF and Heck-type addition products in a homogenized system with sodium decyl sulfate. cod = 1,5-cyclooctadiene.
- Kurahashi, Takuya,Shinokubo, Hiroshi,Osuka, Atsuhiro
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p. 6336 - 6338
(2007/10/03)
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- A highly stereospecific synthesis of (E)-α,β-unsaturated esters
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CrCl2-induced olefination of aldehydes using methyl dichloroacetate exclusively generates (E)-α,β-unsaturated esters in excellent yields. The intermediate α-chloro-β-hydroxy adducts could also be isolated in good yields under conditions of limited reagent.
- Barma, Deb K.,Kundu, Asish,Bandyopadhyay, Anish,Kundu, Abhijit,Sangras, Bhavani,Briot, Anne,Mioskowski, Charles,Falck
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p. 5917 - 5920
(2007/10/03)
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- A catalytic asymmetric synthesis of chiral glycidic acid derivatives through chiral dioxirane-mediated catalytic asymmetric epoxidation of cinnamic acid derivatives
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A novel and practical asymmetric synthesis of chiral glycidic acid derivatives involving methyl (2R,3S)-3-(4-methoxyphenyl)glycidate ((2R,3S)-2a), a key intermediate for diltiazem hydrochloride (1), was developed. Treatment of methyl (E)-4-methoxycinnamate ((E)-3a) with chiral dioxirane, generated in situ from a catalytic amount (5 mol %) of an 11-membered C2-symmetric binaphthyl ketone (R)-7a, provided (2R,3S)-2a in 92% yield and 80% ee. Other cinnamic acid esters and amides were epoxidized by the use of the same procedure to give the corresponding chiral glycidic acid derivatives with up to 95% yield and 92% ee. Higher enantioselectivities in the asymmetric epoxidation of (E)-cinnamates than that of (E)-stilbene derivatives were observed and were proposed to be attributed to a dipole-dipole repulsion between oxygen atoms of an ester group in the cinnamates and those of the lactone moieties in the binaphthyl dioxirane.
- Imashiro, Ritsuo,Seki, Masahiko
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p. 4216 - 4226
(2007/10/03)
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- New and efficient conditions for the Z-selective synthesis of unsaturated esters by the Horner-Wadsworth-Emmons olefination
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The Horner-Wadsworth-Emmons reaction of both 1 (Still's reagent) and 2 (Ando's reagent) with aldehydes was studied. Tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1) was shown to be an efficient additive when the reaction was performed in THF at -78°C. Selectivities close to 95% were obtained in the condensation of 1 with aromatic aldehydes. The use of a 5-fold excess of 18C6 in this reaction had already been reported. However, we have defined conditions in which only catalytic amounts are required.
- Touchard, Fran?ois P.
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p. 5519 - 5523
(2007/10/03)
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- A novel thiourea ligand applied in the Pd-catalyzed Heck, Suzuki and Suzuki carbonylative reactions
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A novel C2 symmetrical and sterically bulky thiourea ligand 1 has been successfully applied to Heck, Suzuki and Suzuki-type carbonylative coupling reactions under aerobic conditions. Since the metal-sulfur bond in the thiourea complexes is stronger than the metal-phosphorus bond of typical phosphine complexes, thiourea ligands generally do not easily dissociate from the metal center under catalytic conditions, which establishes the thiourea 1-based palladium complexes as effective catalysts for the palladium-catalyzed cross-coupling reactions.
- Mingji, Dai,Liang, Bo,Wang, Cuihua,You, Zejin,Xiang, Jing,Dong, Guangbin,Chen, Jiahua,Yang, Zhen
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p. 1669 - 1673
(2007/10/03)
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- An N-C-N pincer palladium complex as an efficient catalyst precursor for the Heck reaction
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The Heck reaction of iodobenzene and methyl acrylate took place smoothly in NMP at 140°C in the presence of 1 mol ppb of the pincer palladium complex [4-tert-butyl-2,6-bis{(3R,7aS)-2-phenylhexahydro-1H-pyrrolo[1,2-c] imidazole-1-on-3-yl}-phenyl]chloropall
- Takenaka, Kazuhiro,Uozumi, Yasuhiro
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p. 1693 - 1696
(2007/10/03)
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- Synthesis of novel palladacycles and their application in heck and Suzuki reactions under aerobic conditions
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(Chemical Equation Presented) Design and synthesis of a novel family of furancarbothioamide-based palladacycles are reported herein. These palladacycles are thermally stable, not sensitive to air or moisture, and are applied effectively in the Heck reaction of aryl halides with terminal olefins and in the Suzuki reaction of aryl halides with arylboronic acids. These reactions were performed under aerobic conditions, leading to turnover numbers (TONs) up to 1 × 105.
- Xiong, Zhengchang,Wang, Nengdong,Dai, Mingji,Li, Ang,Chen, Jiahua,Yang, Zhen
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p. 3337 - 3340
(2007/10/03)
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- Synthesis of N-glyoxyl prolyl and pipecolyl amides and thioesters and evaluation of their in vitro and in vivo nerve regenerative effects
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The recent discovery that small molecule ligands for the peptidyl-prolyl isomerase (PPIase) FKBP12 possess powerful neuroprotective and neuroregenerative properties in vitro and in vivo suggests therapeutic utility for such compounds in neurodegenerative disease. The neurotrophic effects of these compounds are independent of the immunosuppressive pathways by which drugs such as FK506 and rapamycin operate. Previous work by ourselves and other groups exploring the structure-activity relationships (SAR) of small molecules that mimic only the FKBP binding domain portion of FK506 has focused on esters of proline and pipecolic acid. We have explored amide and thioester analogues of these earlier structures and found that they too are extremely potent in promoting recovery of lesioned dopaminergic pathways in a mouse model of Parkinson's disease. Several compounds were shown to be highly effective upon oral administration after lesioning of the dopaminergic pathway, providing further evidence of the potential clinical utility of a variety of structural classes of FKBP12 ligands.
- Hamilton, Gregory S.,Wu, Yong-Qian,Limburg, David C.,Wilkinson, Douglas E.,Vaal, Mark J.,Li, Jia-He,Thomas, Christine,Huang, Wei,Sauer, Hansjorg,Ross, Douglas T.,Soni, Raj,Chen, Yi,Guo, Hongshi,Howorth, Pamela,Valentine, Heather,Liang, Shi,Spicer, Dawn,Fuller, Mike,Steiner, Joseph P.
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p. 3549 - 3557
(2007/10/03)
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