- Structural insight into the anion-water cluster: Stabilised by alcohol and carboxylic acid containing tripodal ligand
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A new flexible N-bridged, unsymmetrical, water-soluble tripodal ligand (L) bearing alcohol and carboxylic acid groups has been synthesised and its solid-state interaction with anions has been investigated. The fully deprotonated ligand encapsulates a sodium cation in a half cryptand bowl-shaped cavity (1). The chloride complex 2, contains a cyclohexane-like water cluster incorporating ligand OH groups. However, complexes with bromide and nitrate (3 and 4) are dimeric. Tetrahedral clusters containing two water molecules and two anions were found in complexes 3 and 4. Perchlorate complex 5 forms perchlorate-methanol adducts. Complex 1 forms a hydrophilic cation-water channel and complexes 2-4 form anion-water channels between the hydrophobic layers of the naphthalene moieties. Complexes 2, 5 and 3, 4 are isostructural in nature having similar packing structures.
- Hoque, Md. Najbul,Basu, Arghya,Das, Gopal
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Read Online
- Extending Cross Metathesis to Identify Selective HDAC Inhibitors: Synthesis, Biological Activities, and Modeling
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Dissymmetric cross metathesis of alkenes as a convergent and general synthetic strategy allowed for the preparation of a new small series of human histone deacetylases (HDAC) inhibitors. Alkenes bearing Boc-protected hydroxamic acid and benzamide and trityl-protected thiols were used to provide the zinc binding groups and were reacted with alkenes bearing aromatic cap groups. One compound was identified as a selective HDAC6 inhibitor lead. Additional biological evaluation in cancer cell lines demonstrated its ability to stimulate the expression of the epithelial marker E-cadherin and tumor suppressor genes like SEMA3F and p21, suggesting a potential use of this compound for lung cancer treatment. Molecular docking on all 11 HDAC isoforms was used to rationalize the observed biological results.
- Bouchet, Samuel,Linot, Camille,Ruzic, Dusan,Agbaba, Danica,Fouchaq, Benoit,Roche, Jo?lle,Nikolic, Katarina,Blanquart, Christophe,Bertrand, Philippe
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Read Online
- Fluorescence turn on sensor for sulfate ion in aqueous medium using tripodal-Cu2+ ensemble
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We report the selective recognition of sulfate anion in aqueous medium at biological pH 7.2 over the other interfering anions based on naphthoic acid bearing tripodal ligand by applying fluorescence turn off-on mechanism. The carboxylic acid groups in the ligand enhance the solubility in water and enable it to form complex with copper salt. Thus formed L-Cu2+ ensemble quench the fluorescence of the parent ligand and in turn recognize sulfate anion via revival of fluorescence intensity. The 1:2 stoichiometry was confirmed by ESI mass spectral data and Job's plot. The average binding constant was found to be 6.2∈×∈108 M-2. [Figure not available: see fulltext.]
- Hoque, Md. Najbul,Basu, Arghya,Das, Gopal
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Read Online
- Novel Thermal Rearrangement of 1-Alkoxycarbonyl-2-aryl-cyclopropanes
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2-Arylcyclopropanes substituted with either one acyl and one alkoxycarbonyl or two alkoxycarbonyl groups on C-1 yield 2-carbonyl-1-naphthol derivatives upon thermolysis at temperatures in the range 210-340 deg C in an unprecedented rearrangement of the cyclopropane ring.
- Alonso, Miguel E.,Chitty, A. Wladimir,Pekerar, Sarah,Borgo, Maria de L.
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Read Online
- Controlling the Gold(I)-Catalyzed 1,5-Allenene Reaction: Construction of Fused Rings with Excellent Diastereoselectivity
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In the present study, the gold(I)-catalyzed reaction of 1,5-allenenes was controlled in such a way that instead of a [2 + 3] cycloaddition, a 5-exo-cyclization with the formation of a carbocation occurred. The latter could be trapped with both oxygen and carbon nucleophiles. In the investigated system, fused tricyclic frameworks with three contiguous stereocenters with excellent chemo- and diastereoselectivity in up to 95% yield were obtained.
- Haberhauer, Gebhard,Semleit, Nina
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supporting information
p. 9635 - 9639
(2021/12/06)
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- CFTR-MODULATING ARYLAMIDES
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The present disclosure relates to heterocyclic compounds, pharmaceutically acceptable salts thereof, and pharmaceutical preparations thereof. Also described herein are compositions and the use of such compounds in methods of treating diseases and conditions mediated by deficient CFTR activity, in particular cystic fibrosis.
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Page/Page column 69; 70; 71
(2021/06/11)
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- Condensed fluorene derivative comprising heterocyclic ring
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The present invention relates to a condensed fluorene derivative comprising a heterocyclic ring and, more particularly, to an intermediate product for manufacturing a heterocyclic ring compound which can show excellent luminance and luminous efficiency when used as an organic light emitting material, while exhibiting excellent element characteristics with a long lifespan.COPYRIGHT KIPO 2020
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Paragraph 0529-0535
(2019/12/25)
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- Visible-Light-Mediated Stereoselective 1,2-Iodoalkylation of Alkynes
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A visible-light-mediated and photocatalyst/initiator-free addition to alkynes has been developed. An atom transfer radical addition (ATRA) mechanistic afforded a broad scope of valuable iodo-substituted alkenyl derivatives with high E/Z-selectivities, which are versatile intermediates for the synthesis of various tri- and tetra- substituted alkenes. (Figure presented.).
- Liu, Jie-Jie,Lan, Ling,Gao, Yu-Ting,Liu, Qi,Cheng, Liang,Wang, Dong,Liu, Li
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supporting information
(2019/02/19)
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- Organic light-emitting diode with high efficiency
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The present disclosure relates to an organic light-emitting diode exhibiting high luminance efficiency, low-voltage operation, and long lifespan and, more particularly, to an organic light-emitting diode, comprising: a first electrode; a second electrode facing the first electrode; and a light-emitting layer and an electron density control layer sequentially arranged between the first electrode and the second electrode wherein the light-emitting layer includes at least one of the amine compounds represented by Chemical Formula A or B and the electron density control layer includes at least one of the compounds represented by Chemical Formulas F to H. The structures of Chemical Formulas A, B, and F to H are as described in the specification.
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Paragraph 0191-0192
(2018/09/02)
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- Novel amine-based compound and organic light emitting device comprising the same
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The present invention relates to a novel amine-based compound and an organic light emitting device comprising the same. The compound is represented by chemical formula 1 or 2, and can be used as a material for an organic material layer of an organic light emitting device for improving the efficiency, the low driving voltage, and/or the lifetime characteristic in the organic light emitting device.COPYRIGHT KIPO 2018
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Paragraph 0277-0280
(2018/09/02)
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- Gold promoted arylative cyclization of alkynoic acids with arenediazonium salts
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Alkynoic acids derived from salicylic acid and analogues undergo arylative cyclization with arenediazonium salts promoted by gold in the absence of external ligands. The reaction is thermally induced and proceeds even in the absence of light. A difference in regioselectivity has been found compared with that observed in the cycloisomerization process of the same type of compounds.
- Carrillo-Arcos, Ulises A.,Porcel, Susana
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supporting information
p. 1837 - 1842
(2018/03/23)
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- BENZOISOQUINOLINONE M1 RECEPTOR POSITIVE ALLOSTERIC MODULATORS
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The present invention is directed to substituted benzoisoquinolinone compounds, their salts, pharmaceutical compositions comprising them and their use in therapy. In particular, the invention is directed substituted benzoisoquinolinone compounds which are muscarinic M1 receptor positive allosteric modulators. The present invention is also directed to uses of the compounds described herein in the potential treatment or prevention of neurological and psychiatric disorders and diseases in which M1 receptors are involved. The present invention is also directed to compositions comprising these compounds. The present invention is also directed to uses of these compositions in the potential prevention or treatment of such diseases in which M1 receptors are involved.
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Page/Page column 34; 35; 45
(2018/02/28)
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- Differentially Substituted Phosphines via Decarbonylation of Acylphosphines
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A new route to phosphines was developed by a method that features a "pre-join and transform" process that proceeds via acylphosphine intermediates that may be readily prepared from carboxylic acids and disubstituted phosphines. The efficient decarbonylations of these acylphosphines using a nickel catalyst delivered the corresponding phosphines. This method shows that the carboxyl group can play a role similar to halides or triflates for introducing a substituted phosphorus atom on an aromatic ring.
- Yu, Rongrong,Chen, Xingyu,Martin, Stephen F.,Wang, Zhiqian
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p. 1808 - 1811
(2017/04/11)
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- Novel compounds for organic light-emitting diode and organic light-emitting diode including the same
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The present invention relates to a compound represented by chemical formula B, and an organic light-emitting device including the same. In the chemical formula B, cyclic groups A1 to A3, structural formulas Q1 and Q2, R1 and R2, L1 to L4, Ar1 to Ar4, E, and F are the same as defined in the present specification. More specifically, provided is a compound for organic light-emitting devices exhibiting excellent device properties such as low voltage driving properties and luminous efficiency.COPYRIGHT KIPO 2017
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Paragraph 0304; 0305-0310
(2017/08/29)
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- Organic light-emitting element capable of low-voltage drive and having long life
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The present invention relates to an organic light-emitting element capable of low-voltage drive and also having a long life, and, more specifically, relates to an organic light-emitting element comprising: a first electrode; a second electrode facing the first electrode; and a light-emitting layer interposed between the first electrode and the second electrode, wherein the light-emitting layer comprises at least one amine compound represented by [chemical formula A] or [chemical formula B], and at least one compound represented by [chemical formula D], and the structures of [chemical formula A], [chemical formula B] and [chemical formula D] are the same as given in the detailed description of the invention.
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Paragraph 0254; 0255; 0256; 0258; 0259
(2017/10/13)
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- ORGANIC LIGHT-EMITTING DIODE WITH HIGH EFFICIENCY AND LONG LIFETIME
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The present invention relates to an organic light-emitting diode exhibiting high efficiency and longevity. The organic light-emitting diode comprises: a first electrode; a second electrode facing the first electrode; and a light-emitting layer interposed between the first electrode and the second electrode, wherein the light-emitting layer contains at least one of the amine compounds represented by Chemical Formula A or Chemical Formula B and at least one of the compounds represented by Chemical Formulas H1 to H7, Chemical Formulas A, B, and H1 to H7 being the same as in the specification.
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Paragraph 0202; 0203
(2018/01/03)
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- Design and Synthesis of a Series of l-trans-4-Substituted Prolines as Selective Antagonists for the Ionotropic Glutamate Receptors Including Functional and X-ray Crystallographic Studies of New Subtype Selective Kainic Acid Receptor Subtype 1 (GluK1) Antagonist (2S,4R)-4-(2-Carboxyphenoxy)pyrrolidine-2-carboxylic Acid
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Ionotropic glutamate receptor antagonists are valuable tool compounds for studies of neurological pathways in the central nervous system. On the basis of rational ligand design, a new class of selective antagonists, represented by (2S,4R)-4-(2-carboxyphenoxy)pyrrolidine-2-carboxylic acid (1b), for cloned homomeric kainic acid receptors subtype 1 (GluK1) was attained (Ki = 4 μM). In a functional assay, 1b displayed full antagonist activity with IC50 = 6 ± 2 μM. A crystal structure was obtained of 1b when bound in the ligand binding domain of GluK1. A domain opening of 13-14° was seen compared to the structure with glutamate, consistent with 1b being an antagonist. A structure-activity relationship study showed that the chemical nature of the tethering atom (C, O, or S) linking the pyrrolidine ring and the phenyl ring plays a key role in the receptor selectivity profile and that substituents on the phenyl ring are well accommodated by the GluK1 receptor.
- Krogsgaard-Larsen, Niels,Delgar, Claudia G.,Koch, Karina,Brown, Patricia M. G. E.,M?ller, Charlotte,Han, Liwei,Huynh, Tri H. V.,Hansen, Stinne W.,Nielsen, Birgitte,Bowie, Derek,Pickering, Darryl S.,Kastrup, Jette Sandholm,Frydenvang, Karla,Bunch, Lennart
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p. 441 - 457
(2017/04/26)
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- Assembly and inhibitory activity of monovalent mannosides terminated with aromatic methyl esters: The effect of naphthyl groups
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A series of monovalent α-D-mannoside ligands terminated with aromatic methyl esters have been synthesized in excellent yields using the Cu(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition (“click chemistry”). These mannosides were designed to have a unique aglycone moiety (tail) that combines a triazole ring attached to aromatic methyl esters via a six carbon alkyl chain. The mannose unit of these ligands was linked at the ortho, meta, and para positions of substituted methyl benzoates and 1-, 3-, and 6-substituted methyl 2-napthaoates. In hemagglutination assays, ligands (32A-38A) showed better inhibitory activities than the standard inhibitor, methyl α-D-mannopyranoside. Overall, the naphthyl-based mannoside ligand (37A) showed the best activity and therefore merits further development.
- Al-Mughaid, Hussein,Al-Zoubi, Raed M.,Khazaaleh, Maha,Grindley, T. Bruce
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- M1 RECEPTOR POSITIVE ALLOSTERIC MODULATORS AND METHODS OF USE THEREOF
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The present invention is directed to compounds of general formula (I) or pharmaceutically acceptable salts thereof, which are M1 receptor positive allosteric modulators and that are useful in the treatment of diseases in which the M1 receptor is involved, such as Alzheimer's disease, schizophrenia, pain or sleep disorders. The invention is also directed to pharmaceutical compositions comprising the compounds, or pharmaceutically acceptable salts thereof, and to the use of the compounds and compositions in the treatment of diseases mediated by the M1 receptor.
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Page/Page column 28; 29; 30
(2017/10/13)
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- Manganese triacetate oxidation of methyl 1-hydroxy-2-naphthalene carboxylates
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Manganese-triacetate mediated oxidation of 1-hydroxy-2-napthalene carboxylates in benzene under anhydrous conditions delivers the dimerized product. However, acetoxylation on the ortho- or para-position, or oxidation to quinones occurs on the 1-hydroxy-3-substituted 2-napthalene carboxylates depending on the nature of the substituents when the reaction is carried out in a mixture of acetic acid/acetonitrile.
- Munive, Laura,Gómez-Calvario, Víctor,Olivo, Horacio F.
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supporting information
p. 2445 - 2447
(2017/05/31)
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- Solvent-Free Synthesis of Salen Ligands and Pd(II)- and Cu(II)-Salen Complexes: Their Use in the Oxidation of α-Tetralones to α-Naphthols
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Racemic trans -cyclohexane-1,2-diamine was allowed to react with eleven aldehydes with different patterns of substitution at the aromatic ring, in the absence of solvent, by manually milling the reagents. The corresponding imines were obtained in moderated to high chemical yields, in only 10 minutes of reaction. A one-pot, two-step preparation of stable complexes of selected imines with Pd(OAc) 2 and Cu(OAc) 2 and the use of these complexes as catalysts in the aromatization of methyl 1-oxo-1,2,3,4-tetrahydronaphthalene-2-carboxylate to the corresponding methyl 1-hydroxynaphthalene-2-carboxylates, is also reported.
- Cívicos, José F.,Coimbra, Juliana S. M.,Costa, Paulo R. R.
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p. 3998 - 4006
(2017/08/29)
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- Condensed fluorene derivative comprising heterocyclic ring
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The present invention relates to a condensed fluorene derivative comprising a heterocyclic ring and, more particularly, to an intermediate product for manufacturing a heterocyclic ring compound which can show excellent luminance and luminous efficiency when used as an organic light emitting diode, while having excellent element characteristics with long lifespan. The heterocyclic ring compound of the present invention is represented by chemical formula A and chemical formula B.COPYRIGHT KIPO 2016
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Paragraph 0529-0535
(2016/10/08)
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- Copper- versus palladium-catalyzed aromatization of 2-(methoxycarbonyl) tetralones: Synthesis of methyl 1-hydroxy-2-naphthoates
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The aromatization of α-tetralones substituted at the β-position by an ester group is reported using either CuI or Pd2(dba)3. In the case of using CuI (10 mol %) as catalyst and Cs2CO3 as base in dioxane, 2-(methoxycarbonyl)-α-tetralones are smoothly converted into the corresponding methyl 1-hydroxy-2-naphthoates at 70 °C under air. Alternatively, Pd2(dba)3 (1.25 mol %) can also be used as catalyst in the presence of K3PO4 as base in toluene also at 70 °C under argon. These are the most straightforward methodologies for the aromatization of these types of α-tetralones. CuI is the catalyst of choice due to higher efficiency, economical and practical reasons.
- Cívicos, José F.,Ribeiro, Carlos M.R.,Costa, Paulo R.R.,Nájera, Carmen
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p. 1897 - 1902
(2016/04/05)
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- Novel aromatic compounds for organic light-emitting diode and organic light-emitting diode including the same
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The present invention relates to an organic light emitting compound represented by chemical formula A, and to an organic light emitting device comprising the same. In the chemical formula A, a cyclic group A_1 to A_3, R_1 to R_11, L, n, a structural formula Q, and a structural formula Aandprime; are the same as described in the specification.COPYRIGHT KIPO 2016
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Paragraph 0302-0308
(2016/10/09)
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- Heterocyclic compound comprising aromatic amine group and organic light-emitting diode including the same
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The present invention relates to a heterocyclic compound comprising an aromatic amine group and an organic light emitting device including the same and, more specifically, to a heterocyclic compound, which has excellent luminance, luminance efficiency, and outstanding long lifespan characteristics when being used as an organic light emitting material. In addition, the present invention further relates to an organic light emitting device including the same.COPYRIGHT KIPO 2016
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Paragraph 0499-0504
(2016/10/07)
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- Oxidative cyclization of alkenoic acids promoted by AgOAc
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Alkenoic acids derived from salicylic acid and analogues undergo an unexpected oxidative cyclization process triggered by AgOAc leading to 4H-benzo[d][1,3]dioxin-4-ones. The process is affected by the substitution on the aryl and the allyl units.
- Carrillo-Arcos, Ulises A.,Rojas-Ocampo, Jonathan,Porcel, Susana
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supporting information
p. 479 - 483
(2016/01/09)
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- Silver(I) and gold(I)-promoted synthesis of alkylidene lactones and 2H-chromenes from salicylic and anthranilic acid derivatives
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Ag(I) and Au(I) efficiently catalyze the cycloisomerization of terminal alkynoic acids into methylene seven-membered ring lactones. Depending on the metal, divergent reaction pathways were found for non terminal alkynoic acids. While Ag(I) led to lactones, Au(I) led to 2H-chromenes coming from the hydroarylation of the alkyne.
- Nolla-Saltiel, Roberto,Robles-Marín, Elvis,Porcel, Susana
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supporting information
p. 4484 - 4488
(2014/08/05)
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- Synthesis of chiral porphyrins and their use in photochemical oxidation of carbonyl compounds
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A series of chiral A4, A2B2, and AB 3 porphyrins bearing proline moieties at the meso-phenyl group has been synthesized. Photostability studies revealed that the number of L-proline units and their position on meso-phenyl rings strongly influence the decomposition rate of the catalyst. 5,10,15-Tris(mesityl)-20-(3- prolinanilidylphenyl)-21,23H-porphyrin is the most stable while porphyrin bearing four 3-prolinanilidylphenyl substituents completely decomposes in CHCl3 within 3 h. Singlet oxygen quantum yields of the conjugates were determined by measuring the peak areas of the NIR emission of 1O2 (1280 nm) generated by these compounds and compared to that generated by the reference standard TPP. Selected porphyrins were tested as catalysts in the photooxidation of carbonyl compounds at the α-position.
- Walaszek, Dominika J.,Maximova, Ksenia,Rybicka-Jasińska, Katarzyna,Lipke, Agnieszka,Gryko, Dorota
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p. 493 - 505
(2014/07/21)
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- Mechanism of alkoxy groups substitution by Grignard reagents on aromatic rings and experimental verification of theoretical predictions of anomalous reactions
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The mechanism of direct displacement of alkoxy groups in vinylogous and aromatic esters by Grignard reagents, a reaction that is not observed with expectedly better tosyloxy leaving groups, is elucidated computationally. The mechanism of this reaction has been determined to proceed through the inner-sphere attack of nucleophilic alkyl groups from magnesium to the reacting carbons via a metalaoxetane transition state. The formation of a strong magnesium chelate with the reacting alkoxy and carbonyl groups dictates the observed reactivity and selectivity. The influence of ester, ketone, and aldehyde substituents was investigated. In some cases, the calculations predicted the formation of products different than those previously reported; these predictions were then verified experimentally. The importance of studying the actual system, and not simplified models as computational systems, is demonstrated.
- Jimenez-Oses, Gonzalo,Brockway, Anthony J.,Shaw, Jared T.,Houk
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p. 6633 - 6642
(2013/06/04)
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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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- α-Hydroxylation of 1,3-dicarbonyl compounds catalyzed by polymer-incarcerated gold nanoclusters with molecular oxygen
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α-Hydroxylation of 1,3-dicarbonyl compounds was successfully catalyzed by carbon-stabilized polymer-incarcerated gold nanoclusters (PI/CB-Au). The reaction proceeded under mild conditions using molecular oxygen as oxidant with wide substrate scopes and the catalyst could be recovered and reused by a simple operation. The control experiments and the reaction monitoring revealed that α-peroxide compounds were reaction intermediates, and PI/CB-Au also catalyzed isomerization.
- Miyamura, Hiroyuki,Kobayashi, Shu
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p. 976 - 978
(2012/10/30)
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- Direct displacement of alkoxy groups of vinylogous esters by grignard reagents
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The direct displacement of alkoxy groups from the β position of aromatic and unsaturated esters and ketones is described. The reaction is chemo- and regioselective, displaying wide substrate scope.
- Brockway, Anthony J.,González-López, Marcos,Fettinger, James C.,Shaw, Jared T.
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supporting information; experimental part
p. 3515 - 3518
(2011/06/24)
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- Design, synthesis, structure, and dehydrogenation reactivity of a water soluble o-iodoxybenzoic acid derivative bearing a trimethylammonium group
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5-Trimethylammonio-1, 3-dioxo-1, 3-dihydro-1λ5-benzo[d][1, 2]iodoxol-1-ol anion (AIBX 1a), an o-iodoxybenzoic acid (IBX) derivative having the trimethylammonium moiety on its phenyl ring, possesses very good solubility in water and distinct oxidative properties from IBX, which is demonstrated in the oxidation of various β-keto esters to the corresponding dehydrogenated products using water as cosolvent. The regeneration of AIBX 1a can be easily realized from the reaction mixture due to its good water solubility.2011 American Chemical Society.
- Cui, Li-Qian,Dong, Zhi-Lei,Liu, Kai,Zhang, Chi
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p. 6488 - 6491
(2012/02/02)
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- MOLECULARLY IMPRINTED SMART POLYMERS (MISPs)
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Molecularly imprinted smart polymers (MISPs) are provided herein, as well as novel monomers for preparing MISPs, and processes for preparing MISPs. The MISPs can be used applications such as, for example, detecting/absorbing or isolating biological and non-biological agents. The MISPs described herein comprise responsive monomeric units which undergo a physico-chemical change (e.g., a bond formation or cleavage) in response to an external change, such that the MISP selectively binds to a target molecule and releases a bound target molecule in response to the external change.
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- Rapid access to benzo-annelated heterocycles, naphthalenes, and polysubstituted benzenes through a novel benzannulation reaction
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A novel, efficient, and powerful methyl mercaptoacetate triggered benzannulation reaction is described. The precursors are heterocyclic, aromatic or acyclic compounds bearing a carbonyl group at ortho position to an internal alkyne. The methodology does not require transition-metal catalysts and moreover it is general for the preparation of wide range of benzo-annelated heterocycles, naphthalenes and benzenes.
- Cikotiene, Inga,Buksnaitiene, Rita,Sazinas, Rokas
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experimental part
p. 706 - 717
(2011/03/19)
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- Synthesis and application of oxadiazines as chiral ligands for the enantioselective addition of diethylzinc to aldehydes
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A series of oxadiazines derived from l-phenylalanine bearing phenolic substituents have been synthesized in a multistep, one pot process. This process involves the reaction of a mixed anhydride with a β-hydrazino alcohol, methanesulfonylation of the alcohol moiety, and base induced cyclization. The resultant oxadiazines were employed in the asymmetric addition of diethylzinc to aldehydes.
- Dean, Melissa A.,Hitchcock, Shawn R.
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experimental part
p. 2471 - 2478
(2011/02/22)
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- Facile photochemical synthesis of 1,1′-binaphthyls
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The photochemical synthesis of highly functionalized 1,1′-binaphthyls 9 by photodehydro-DielsAlder reaction of esters 8 is reported. It was found that -stacking interactions between a naphthyl moiety already present in the reactants 8 and an aryl group tethered in the propargyl position of these esters clearly influence the regio- and diastereoselectivity of the reaction. The formation of undesired phenanthrenes 10 could be suppressed by introduction of a blocking methoxy group in the 2-position of the naphthyl moiety. In one case, a diastereomeric ratio of 32:68 was achieved. This is the first example of an atropselective synthesis of biaryls by a photodehydro-DielsAlder reaction. CSIRO 2008.
- Wessig, Pablo,Mller, Gunnar
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p. 569 - 572
(2008/12/22)
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- A novel multicomponent reaction of arynes, β-keto sulfones, and Michael-type acceptors: A direct synthesis of polysubstituted naphthols and naphthalenes
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(Chemical Equation Presented) A novel multicomponent reaction of arynes, β-keto sulfones, and Michael-type acceptors is presented, providing an efficient method for the synthesis of polysubstituted naphthols and polysubstituted naphthalenes. Further investigation suggests that the tandem reaction may proceed via a sequential nucleophilic attack to arynes, intramolecular nucleophilic substitution followed by a Michael addition, and a ring closure - elimination process.
- Huang, Xian,Xue, Jian
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p. 3965 - 3968
(2008/02/01)
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- α-EWG-substituted enones: Suitable substrates for ring-closing metathesis
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The A-ring of hexacyclinic acid has been synthesised, using a ring-closing metathesis involving an α-EWG-substituted enone as the key step. We have then explored the scope of this reaction, which gives access to various 5- and 6-membered rings. Georg Thieme Verlag Stuttgart.
- Toueg, Julie,Prunet, Jo?lle
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p. 2807 - 2811
(2008/02/11)
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- Factors affecting the selection of products from a photochemically generated singlet biradical
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The chemistries of a monoradical of the ultrafast "radical-clock" type and a structurally related singlet biradical, generated by Norrish type II photochemistry, are compared. The monoradical is found to undergo the characteristic ring-opening reaction of its class at about 1010 s-1 at room temperature. However, the singlet biradical shows no evidence of the analogous ring-opening reaction. The contrasting chemistry is traced not to a fundamental difference in electronic structure of the two intermediates, but rather to a steric interaction that the biradical alone would have to suffer during the ring opening. Although the magnitude of the steric hindrance is small (estimated 15-20 kJ mol-1), it is enough to shut down the reaction, because the biradical has other facile product-forming reactions available. The Royal Society of Chemistry 2005.
- Broyles, David A.,Carpenter, Barry K.
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p. 1757 - 1767
(2007/10/03)
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- The six-membered intramolecular hydrogen bond position as a switch for inducing an excited state intramolecular proton transfer (ESIPT) in esters of o-hydroxynaphthoic acids
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The substituted naphthalene compounds investigated in this paper, i.e., methyl 2-hydroxy-3-naphthoate (MHN23), methyl l-hydroxy-2-naphthoate (MHN12), and methyl 2-hydroxy-l-naphthoate (MHN21), show a strong intramolecular hydrogen bond {-IMHB) in their ground electronic state. The relative position of the IMHB in the naphthalene skeleton acts as a switch and controls the yield of an excited state intramolecular proton transfer (ESIPT) process. As a matter of fact, only MHN23 exhibits a proton transfer (PT) emission and possesses a theoretically proved ESIPT mechanism. The role that the ESIPT mechanism plays on the photostability of the molecule MHN23 is unravelled by comparison with the model compounds methyl salicylate (MS), MHN12, and MHN21. On one hand, the low photoreaction quantum yield, N = 0.00015, and therefore the high photostability of MS, under direct ultraviolet (UV) irradiation, has been explained due to the photophysics of its proton transfer tautomer. On the other hand, (a) the two benzene-fused ring derivatives of methyl salicylate, MHN12 and MHN21, also possess a great photostability to UV radiation, and they do not support an ESIPT mechanism; and (b) although MHN23 exhibits an excited state proton transfer, its efficiency is only of 1.8%, and the photostability is 5 times larger than that of MS. As a result, the photostability of MHN23, MHN12, and MHN21 does not rely on the photophysics of their proton transfer tautomers but on the nonradiative dynamics of their respective normal tautomers. We present experimental evidence which supports the above-mentioned statement on the existence of distinctive nonradiative channels for the molecules MHN23, MHN12, and MHN21.
- Catalan, Javier,Del Valle, Juan C.,Palomar, Jose,Diaz, Cristina,De Paz, Jose L. G.
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p. 10921 - 10934
(2007/10/03)
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- Palladium-catalyzed carbonylative cyclization of 1-iodo-2-alkenylbenzenes
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The Pd-catalyzed carbonylation of ω-vinyl-substituted o-iodoalkenylbenzenes 1-4 can provide up to modest yields (50-60%) of 5- and 6-membered Type I cyclic acylpalladation products, i.e., α,β-unsaturated cyclic ketones, in the absence of an external nucleophile and high yields of 5- and 6-membered Type II cyclic acylpalladation products, i.e., α- or β-((alkoxycarbonyl)methyl)substituted cyclic ketones in the presence of an alcohol, e.g., MeOH. In cases where no such processes are available, other side reactions, such as cyclic carbopalladation, polymeric acylpalladation, and trapping of acylpalladiums via esterification and other processes may become predominant. Neither smaller, i.e., 3- or 4-membered, nor 7-membered or larger cyclic ketones appear to be accessible by the reaction. In most cases, the exo-mode cyclic acylpalladation takes place exclusively. However, the cyclic acylpalladation of 3 proceeds exclusively via endo-mode cyclization to give 5-membered ketones. Substitution of one or more hydrogens in the ω-vinyl group with carbon groups has significant effects on the reaction course. Those substrates containing a 1,2-disubstituted alkenyl group in place of a vinyl group, i.e., 19-22 and 24 excluding 25, can give monomeric cyclic acylpalladation products in high yields. These results represent a major deviation from those obtained with 1 and 2. In the absence of an external nucleophile, formation of Type I cyclic acylpalladation products is, in some cases, accompanied by Type III cyclic acylpalladation involving trapping of acylpalladiums by internal enolates. In the presence of MeOH or other alcohols, Type II acylpalladation products have been obtained in respectable yields from 19-20, 23, and 24. In the presence of an alcohol, premature esterification can be a serious side reaction. However, this problem can be alleviated using i-PrOH or t-BuOH in place of MeOH in combination with appropriate solvents, typically those of lower polarity. Heteroatom-containing substituents on the ω-vinyl groups also exert significant effects on cyclic acylpalladation. Electron-donating substituents tend to lead to high yields of cyclic acylpalladation products, while electron-withdrawing alkoxycarbonyl groups conjugated with the ω-alkenyl group tend to give lower yields of cyclic acylpalladation products. With Me3Si and alkoxycarbonyl groups products of apparent endo-mode cyclic acylpalladation, i.e., naphthols, have been obtained in significant yields (25-50%). Free OH and other nucleophilic heteroatom groups can seriously interfere with cyclic acylpalladation, and they must be appropriately protected in most cases, although there are indications that acylpalladation-lactonization tandem processes similar to Type II cyclic acylpalladation might be developed.
- Negishi, Ei-Ichi,Copéret, Christophe,Ma, Shengming,Mita, Takeshi,Sugihara, Takumichi,Tour, James M.
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p. 5904 - 5918
(2007/10/03)
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- Anionic Cycloaddition with Thiophthalides: an Integrated Approach to the Synthesis of Olivin and Pillaromycinone
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A systematic study of the potential reactivity of the thiophthalides 4 and 18 - 20 as 1,4-dipolar synthons, has shown that 3-phenylthiothiophthalide 19 is the best annulating agent for the preparation of tricyclic intermediates related to olivin.The reagent 19 underwent anionic cycloaddition with cyclohex-2-enone 5a in the presence of lithium tert-butoxide to give the anthracenones 24a and 25 in a combined yield of 90percent.
- Majumdar, Gita,Pal, Ranjan,Murty, Kadiyala V. S. N.,Mal, Dipakranjan
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p. 309 - 316
(2007/10/02)
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- REACTION OF SINGLET OXYGEN WITH ENOLIC TAUTOMERS OF β-DICARBONYLS. α-HYDROXYLATION OF 2-ACYL- AND 2-CARBOALKOXY-3,4-DIHYDRONAPHTHALEN-1(2H)-ONES
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Dye-sensitized photooxidation of enolic tautomers of naphthalenones (5) gave hydroperoxynaphthalenones (6) and naphthols (7).Deoxygenation of 6 by triphenylphosphine gave hydroxynaphthalenones (8).
- Yoshioka, Michikazu,Nishioka, Takashi,Hasegawa, Tadashi
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p. 1471 - 1474
(2007/10/02)
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- N-1H-tetrazol-5-yl-2-naphthalene carboxamides and their use as antiallergy and antiinflammatory agents
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Novel naphthalene derivatives having antiallergy and antiinflammatory activity.
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- BORON TRICHLORIDE CATALYZED ORTHO CARBONYLATION OF PHENOLS: SYNTHESIS OF 2-HYDROXY-ARYL-CARBOXYAMIDES AND -KETONES.
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In the presence of equimolar quantity of BCl3, phenols 1 react with isocyanates and acyl chlorides to give, usually with good-excellent yields, 2-hydroxy-aryl-carboxy-amides 2 and 2-hydroxy-aryl-ketones 3 respectively.A distinctive behaviour of BCl3 in comparison with other Lewis acids is observed.
- Piccolo, Oreste,Filippini, Lucio,Tinucci, Laura,Valoti, Ermanno,Citterio, Attilio
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p. 885 - 892
(2007/10/02)
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- Strong Base Induced Cycloaddition of Homophthalic Anhydrides Leading to peri-Hydroxy Polycyclic Compounds
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A new and exceptionally facile cycloaddition of the alkaline metal salt of homophthalic anhydrides (1a,b) is described.The anions of the anhydrides 1a,b undergo cycloadditions with various dienophiles (5-14) to give the corresponding peri-hydroxy polycyclic compounds (15-26) in good yields under extremely mild conditions, whereas thermal cycloaddition of 1a,b requires high temperatures.
- Tamura, Yasumitsu,Sasho, Manabu,Nakagawa, Kiyomi,Tsugoshi, Teruhisha,Kita, Yasuyuki
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p. 473 - 478
(2007/10/02)
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