- Carbonylative Suzuki coupling reactions catalyzed by ONO pincer–type Pd(II) complexes using chloroform as a carbon monoxide surrogate
-
Benzoylhydrazone Schiff base–ligated three new ONO pincer–type palladium(II) complexes, [(PdL1(PPh3)] (1), [(PdL2(PPh3)] (2), and [(PdL3(PPh3)] (3), were synthesized by the reaction of the respective ligand, N-(2-hydroxybenzylidene)benzohydrazide (HL1), N-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (HL2), or N-(5-bromo-2-hydroxybenzylidene) benzohydrazide (HL3), with Pd(OAc)2 and PPh3 in methanol and isolated as air-stable reddish-orange crystalline solids in high yields (78%–83%). All three complexes were fully characterized by elemental analysis, Fourier-transform infrared spectroscopy, UV–Visible, 1H nuclear magnetic resonance (NMR), 13C{1H} NMR, and 31P{1H} NMR spectroscopic studies. The molecular structure of all three complexes was established unambiguously by single-crystal X-ray diffraction studies which revealed a distorted square planar geometry of all three complexes. The ONO pincer–type ligands occupied three coordination sites at the palladium, while the fourth site is occupied by the monodentate triphenylphosphine ligand. The catalytic potential of all three complexes was explored in the carbonylative Suzuki coupling of aryl bromides and iodides with arylboronic acids to yield biaryl ketones, using CHCl3 as the source of carbonyl. The reported protocol is convenient and safe as it obviates the use of carbon monoxide (CO) balloons or pressured CO reactors which are otherwise needed for the carbonylation reactions. The methodology has been successfully applied to the synthesis of two antineoplastic drugs, namely, phenstatin and naphthylphenstatin, in good yields (81% and 85%, respectively). Under the optimized reaction conditions, complex 2 exhibited the best catalytic activity in the carbonylative Suzuki couplings. The reported catalysts have wide reaction scope with good functional group tolerance. All catalysts could be retrieved from the reaction after completion and recycled up to three times with insignificant loss in the catalytic activity.
- Layek, Samaresh,Agrahari, Bhumika,Ganguly, Rakesh,Das, Parthasarathi,Pathak, Devendra D.
-
-
- Analysis of the degradation mechanism of the polyarylene ether anion-exchange membrane for alkaline fuel cell and water-splitting cell applications
-
Model compounds of benzyltrimethylammonium (BTMA)-modified polyethersulfone, polyetheretherketone, and polyetheroctafluorobiphenyl were synthesized to analyze the degradation mechanism in alkaline fuel cell and water-splitting cell applications. From the
- Miyanishi, Shoji,Yamaguchi, Takeo
-
p. 8036 - 8044
(2017/08/14)
-
- Synthesis on novel Tamoxifen derivatives
-
The design and synthesis of derivatives of 4-hydroxy-Tamoxifen as potential antagonists of the nuclear receptor LRH-1 are described. Stereoselective McMurry coupling was used to generate the desired internal alkene and a novel method for the synthesis of
- Rey, Jullien,Hu, Haipeng,Snyder, James P.,Barrett, Anthony G.M.
-
p. 9211 - 9217
(2012/11/07)
-
- An improved synthesis of hydroxy aryl ketones by fries rearrangement with methanesulfonic acid/methanesulfonic anhydride
-
Methanesulfonic acid treated with methanesulfonic anhydride effectively mediates the Fries rearrangement of aryl esters to give hydroxy aryl ketones with high yields. Georg Thieme Verlag Stuttgart · New York.
- Jeon, Ingyu,Mangion, Ian K.
-
experimental part
p. 1927 - 1930
(2012/10/08)
-
- PROCESS FOR DEMETHYLATING AROMATIC METHYL ETHERS USING 3 -MERCAPTOPROPIONIC ACID
-
The present application discloses a process for demethylating aromatic methyl ethers by reaction with 3 -mercaptopropionic acid or salts thereof. One preferred example is the demethylation of venlafaxine forming 0 - desmethylvenlafaxine.
- -
-
Page/Page column 16
(2012/01/04)
-
- Process for demethylating aromatic methyl ethers using 3-mercaptopropionic acid
-
The present application discloses a process for demethylating aromatic methyl ethers by reaction with 3-mercaptopropionic acid or salts thereof. One preferred example is the demethylation of venlafaxine forming O-desmethylvenlafaxine.
- -
-
Page/Page column 10
(2012/01/03)
-
- Tuning the color switching of naphthopyrans via the control of polymeric architectures
-
A range of polymerisable photochromic naphthopyrans were prepared via the synthesis of an acrylate moiety on either the naphthalene ring (R) and/or the di-aryl (Ar) rings on the 3-position of the naphthopyran. The monomers obtained (NA) were copolymerised
- Sriprom, Wilasinee,Neel, Marjorie,Gabbutt, Christopher D.,Heron, B. Mark,Perrier, Sebastien
-
p. 1885 - 1893
(2008/02/05)
-
- Tandem catalysis: Access to ketones from aldehydes and arylboronic acids via rhodium-catalyzed addition/oxidation
-
Direct cross-coupling reactions of aromatic aldehydes with arylboronic acids afforded ketones in high yields and under mild conditions in the presence of a rhodium catalyst, acetone and a base. This new reaction, involving a formal aldehyde C-H bond activation, is believed to proceed via a tandem process involving addition of the organometallic species to the aldehyde followed by oxidation by β-hydride transfer.
- Mora, Guilhem,Darses, Sylvain,Genet, Jean-Pierre
-
p. 1180 - 1184
(2008/09/16)
-
- Chiral organic radical cation and dication. A reversible chiroptical redox switch based on stepwise transformation of optically active tetrakis(p-alkoxyphenyl)ethylenes to radical cations and dications
-
Optically active tetrakis(p-alkoxyphenyl)ethylenes were found to function as reversible chiroptical switches upon redox transformations. Successive one-electron oxidations of chirally modified tetraarylethylene to the corresponding radical cation and then to the dication led to dramatic changes in the electronic absorption and circular dichroism (CD) spectra. The neutral species showed no color or CD in the visible region, while the radical ion was blue in color and exhibited a weak Cotton effect, with the dication green and giving an intense Cotton effect and a sign opposite that observed for the radical cation, at a longer wavelength. Molecular orbital calculations and X-ray crystallographic studies clearly indicate that the olefinic C=C bond is significantly twisted in the dication to minimize the electrostatic and steric repulsions. By lowering the temperature of the dication, the twist around the double bond is more firmly fixed in either P or M chirality to give a stronger Cotton effect and a larger anisotropy (g) factor. Since the spectral changes are completely reversible and reproducible for multiple redox cycles, this chiral redox system can be used in novel redox-driven chiroptical applications, such as molecular switches and memory devices, in which the information is written/read chiroptically in the ternary mode, giving zero CD signal in the neutral form, positive CD for the radical cation, and negative CD for the dication at a given wavelength.
- Mori, Tadashi,Inoue, Yoshihisa
-
p. 2728 - 2740
(2008/03/14)
-
- Benzophenone derivatives and related compounds as potent histamine H3-receptor antagonists and potential PET/SPECT ligands
-
Para-substituted aromatic ethers with benzophenone or related structural elements and a 3-(1H-imidazol-4-yl)propyloxy moiety were prepared by Mitsunobu-type ether synthesis or SNAr reaction. Most of the title compounds possess high antagonist potency in histamine H3-receptor assays in vitro as well as in vivo in mouse CNS following oral administration. After defining 4-(3-(1H-imidazol-4-yl)propyloxy)phenyl phenyl methanone as a new lead, structure-activity relationships were investigated for this new class of compounds. Substitution of the meta′-position of the benzophenone moiety with halogen atoms (e.g., iodine, fluorine) led to compounds with high antagonist potency in vitro as well as in vivo (Ki = 9.3 and 4.3 nM, ED50 = 0.7 and 0.47 mg/kg p.o., 18 and 12, respectively). A receptor profile of several functional in vitro assays for several biogenic amine receptors for the meta′-iodinated derivative demonstrated high selectivity toward the histamine H3 receptor.
- Sasse, Astrid,Ligneau, Xavier,Sadek, Bassem,Elz, Sigurd,Pertz, Heinz H.,Ganellin, C. Robin,Arrang, Jean-Michel,Schwartz, Jean-Charles,Schunack, Walter,Stark, Holger
-
-
- Envirocat EPIC(R) as a novel catalyst for acylation of anisole using benzoic acids
-
Friedel-Crafts acylation of anisole has been carried out using Envirocat EPIC(R) as a novel heterogenous catalyst and benzoic acids under reflux condition. This method is suitable for regioselective acylation of activated aromatics with benzoic acids having electron-donating substituents.
- Bandgar,Sadavarte
-
p. 2587 - 2590
(2007/10/03)
-
- Studies on the topography of biomembranes: regioselective photolabelling in vesicles with the tandem use of cholesterol and a half-membrane phospholipidic probe
-
The synthesis of two photosensitive phospholipids built to be incorporated into a monolayer of DMPC vesicles is described.Upon irradiation of bilayer systems containing them, they do label the DMPC chains, with very poor site-selectivity.Addition of chole
- Hahn, Wolfgang,Fredriksen, Siw Bodil,Dolle, Valerie,Nakatani, Yoichi,Ourisson, Guy
-
p. 915 - 926
(2007/10/03)
-
- Polymerisation and Related Reactions involving Nucleophilic Aromatic Substitution. Part 1. The Rates of Reaction of Substituted 4-Halogenobenzophenones with the Potassium Salts of Substituted 4-Hydroxybenzophenones
-
The rate of displacement of fluorine from 4'-X,4-fluorobenzophenones by the potassium salts of 4'-X,4-hydroxybenzophenones (X = CF3, Cl, F, H, OPh, and OMe) has been studied at 175-225 deg C in diphenyl sulphone as solvent.Comparison with the corresponding rate of displacement of chlorine indicates that the reaction is a bimolecular nucleophilic aromatic substitution.The reaction obeys the Hammett equation using normal ? values for substitution in both the substrate (ρ 1.19) and the phenolate (ρ -0.53).There is also a marked salt effect on the reaction rate and this has been included with the substituent constants in a general equation for the calculation of rate coefficients.The effect of an O- substituent is more marked than would have been expected from the previous range of ? values ascribed to this substituent.
- Ridd, John H.,Yousaf, Taher I.,Rose, John B.
-
p. 1729 - 1734
(2007/10/02)
-
- Production of hydroxy arylophenones
-
Production of a hydroxy arylophenone by reacting an aromatic carboxylic acid Ar(--CO2 H)p where Ar is an aromatic radical, (--CO2 H) is an aromatic carboxylic acid group, and p is 1 or 2 with an aromatic compound H--Ar'--OH where Ar' is an aromatic radical and --H and --OH are aromatically bound para to each other in a benzenoid ring, in the presence of an alkyl sulphonic acid, particularly methane sulphonic acid, to produce a hydroxy arylophenone of formula Ar(--CO--Ar'--OH)p where the carbonyl and hydroxyl groups are para to each other in the hydroxyl-containing benzenoid ring of Ar'. The production of the hydroxy arylophenone proceeds through the intermediate ester (H--Ar'--O--CO--)p Ar and the production of the hydroxy arylophenone starting from the ester is also claimed.
- -
-
-