- Total synthesis of chromanol 293B and cromakalim via stereoselective amination of chiral benzylic ethers
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Stereoselective benzylic amination reaction is important for their further application as pharmaceuticals and agrochemicals, and other chemical entities. Herein, we describe the diastereoselective amination of 1,2-anti-dialkoxychromane on chromane framewo
- Ma, Sang-Ho,Kim, Yeon Su,Jung, Jun Min,Boggu, Pulla Reddy,Kim, Seung Chan,Kim, In Su,Jung, Young Hoon
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- CONTROLLED-DELIVERY CROMAKALIM PRODRUGS
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The present invention provides cromakalim prodrugs, compositions, and their use for the modulation of ATP-sensitive potassium (KATP) channels for therapeutic purposes.
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Page/Page column 167-169
(2021/06/22)
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- Chiral Manganese Aminopyridine Complexes: the Versatile Catalysts of Chemo- and Stereoselective Oxidations with H2O2
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In the last decade, manganese(II) complexes with N-donor tetradentate aminopyridine ligands emerged as efficient catalysts of enantioselective epoxidation of olefins and direct selective oxidation of C?H groups in complex organic molecules, with environmentally benign oxidant hydrogen peroxide. In this personal account, we summarize the progress of these catalysts with regard to ligands design, structure-reactivity correlations, evaluation of the substrate scope, as well as mechanistic studies, shedding light on the nature of active sites and the mechanisms of selective oxygenations. Several practically promising catalytic syntheses with the aid of Mn aminopyridine catalysts are exemplified.
- Ottenbacher, Roman V.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
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- Asymmetric epoxidation of alkenes catalyzed by a porphyrin-inspired manganese complex
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A novel strategy for catalytic asymmetric epoxidation of a wide variety of olefins by a porphyrin-inspired chiral manganese complex using H 2O2 as a terminal oxidant in excellent yield with up to greater than 99% ee has been successfully developed.
- Dai, Wen,Li, Jun,Li, Guosong,Yang, Hua,Wang, Lianyue,Gao, Shuang
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p. 4138 - 4141
(2013/09/12)
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- Immobilized dimeric chiral Mn(III) salen complex on short channel ordered mesoporous silica as an effective catalyst for the epoxidation of non-functionalized alkenes
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Chiral dimeric Mn(III) salen complex with 1R, 2R-(-)-diaminocyclohexane collar was immobilized on short channel large pore sized silica through a long linker of {(CH2)3-NH-melamine-piperazine} to investigate its performance in enanti
- Roy, Tamal,Kureshy, Rukhsana I.,Khan, Noor-Ul H.,Abdi, Sayed H.R.,Sadhukhan, Arghya,Bajaj, Hari C.
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experimental part
p. 6314 - 6322
(2012/08/28)
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- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
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Page/Page column 45-49; 55
(2010/12/31)
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- Development of new HPLC chiral stationary phases based on native and derivatized cyclofructans
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An unusual class of chiral selectors, cyclofructans, is introduced for the first time as bonded chiral stationary phases. Compared to native cyclofructans (CFs), which have rather limited capabilities as chiral selectors, aliphatic-and aromatic-functionalized CF6s possess unique and very different enantiomeric selectivities. Indeed, they are shown to separate a very broad range of racemic compounds. In particular, aliphatic-derivatized CF6s with a low substitution degree baseline separate all tested chiral primary amines. It appears that partial derivatization on the CF6 molecule disrupts the molecular internal hydrogen bonding, thereby making the core of the molecule more accessible. In contrast, highly aromaticfunctionalized CF6 stationary phases lose most of the enantioselective capabilities toward primary amines, however they gain broad selectivity for most other types of analytes. This class of stationary phases also demonstrates high "loadability" and therefore has great potential for preparative separations. The variations in enantiomeric selectivity often can be correlated with distinct structural features of the selector. The separations occur predominantly in the presence of organic solvents.
- Sun, Ping,Wang, Chunlei,Breitbach, Zachary S.,Zhang, Ying,Armstrong, Daniel W.
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experimental part
p. 10215 - 10226
(2010/05/01)
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- Asymmetric epoxidation of cis-alkenes mediated by iminium salts: Highly enantioselective synthesis of levcromakalim
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(Chemical Equation Presented) A range of cis-substituted olefins has been epoxidized with a new dihydroisoquinolinium salt catalyst, using tetraphenylphosphonium monoperoxysulfate as the stoichiometric oxidant, giving ee's of up to 97%. The reaction has been used as the key step in an enantioselective synthesis of the antihypertensive agent levcromakalim.
- Page, Philip C. Bulman,Buckley, Benjamin R.,Heaney, Harry,Blacker, A. John
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p. 375 - 377
(2007/10/03)
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- Use of a combination of active substances containing bioquinones for the production of cosmetic or dermatological preparations
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The invention relates to the use of a compound or several compounds from the group of bioquinones a) in combination with a compound or several compounds from the group of potassium channel openers and/or b) in combination with a compound or several compounds from the group of 5-alpha-reductase inhibitors, for the production of cosmetic or dermatological preparations for treatment of the scalp and for hair in order to prolong the anagenic phase and/or for the treatment and prophylaxis of seborrhoeic symptoms, optionally by additionally using one or several compounds from the group formed from carnitine, arginine, succinic acid, folic acid, conjugated fatty acids and respectively the derivatives thereof, in addition to antioxidants.
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- Process for preparing benzoypyranol derivatives
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A process for the preparation of a pure (3S,4R)-isomer of a compound of formula (A): STR1 wherein the substituents are herein defined in which the pyrrolidonyl or piperidonyl ring is formed by cyclizing an appropriate precursor dihydrobenzopyranol compound that has already been resolved to the (3S,4R)-configuration, or a mixture in which the (3S,4R)-configuration predominates with respect to the (3S,4R)-configuration.
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- Structural Modifications of the Potassium Channel Activator Cromakalim: The C-3 Position
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The syntheses of a selection of C-3 analogues of 6-cyano-3,4-dihydro-2,2-dimethyl-4-(2-oxopyrrolidin-1-yl)-2H-1-benzopyran-3-ol, the potassium channel activator cromakalim 1, are described.Particular interest has focused on the corresponding 3-ketone 2 and compounds in which the hydroxy group of 1 has been replaced by fluorine, carbon and nitrogen containing residues.The hindered neopentylic nature of the C-3 hydroxy group in 1 has a marked effect on its reactivity and has necessitated the independent synthesis of many of these analogues from simpler precursors rather than from the direct modification of compound 1 itself.
- Buckle, Derek R.,Houge-Frydrych, Catherine S. V.,Pinto, Ivan L.,Smith, David G.,Tedder, John M.
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- Enantiomerically pure epoxychromans via asymmetric catalysis
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A practical and highly effective process for the asymmetric epoxidation of several 2,2-dimethylchromene derivatives is reported. Catalysis by Mn(salen) complex 4 in all cases affords epoxychromans with >90% ee, and this method has been applied to the synthesis of two recently developed antihypertensive agents in enantiomerically pure form.
- Lee,Muci,Jacobsen
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p. 5055 - 5058
(2007/10/02)
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- AN UNUSUAL HYDROXYL INVERSION MEDIATED BY DAST
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Trans-3-hydroxy-4-(2-oxopyrrolidin-1-yl) benzopyrans have been shown to undergo inversion to cis-3-hydroxy-4-(2-oxopyrrolidin-1-yl) benzopyrans in moderate yield on treatment with diethylaminosulphur trifluoride (DAST).
- Houge-Frydrych, Catherine S.V.,Pinto, Ivan L.
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p. 3349 - 3350
(2007/10/02)
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- 4-(2-hydroxy-1-pyrrolidinyl and 1-piperidinyl)-2H-benzo[b]-pyran-3-ol derivatives
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Compounds of formula (I): STR1 wherein: either one of R1 and R2 is hydrogen and the other is selected from the class of C1-6 alkylcarbonyl, benzoyl, C1-6 alkoxycarbonyl, C1-6 alkylcarbonyloxy, C1-6 alkylhydroxymethyl, nitro, cyano, chloro, trifluoromethyl, C1-6 alkylsulphinyl, C1-6 alkylsulphonyl, C1-6 alkoxysulphinyl, C1-6 alkoxysulphonyl, C1-6 alkylcarbonylamino, C1-6 alkoxycarbonylamino, C1-6 alkyl-thiocarbonyl, C1-6 alkoxy-thiocarbonyl, C1-6 alkyl-thiocarbonyloxy, C1-6 alkyl-thiolmethyl, formyl or aminosulphinyl, aminosulphonyl or aminocarbonyl, the amino moiety being optionally substituted by one or two C1-6 alkyl groups, or C1-6 alkylsulphinylamino, C1-6 alkylsulphonylamino C1-6 alkoxysulphinylamino or C1-6 alkoxysulphonylamino or ethylenyl terminally substituted by C1-6 alkylcarbonyl, nitro or cyano, or --C(C1-6 alkyl)NOH or --C(C1-6 alkyl)NNH2, or one of R1 and R2 is nitro, cyano or C1-3 alkylcarbonyl and the other is methoxy or amino optionally substituted by one or two C1-6 alkyl or by C2-7 alkanoyl; one of R3 and R4 is hydrogen or C1-4 alkyl and the other is C1-4 alkyl or R3 and R4 together are C2-5 polymethylene having anti-hypertensive activity.
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- Chromanol derivatives
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Compounds of formula (I): STR1 wherein: either one of R1 and R2 is hydrogen and the other is selected from C1-6 alkylcarbonyl, C1-6 alkoxycarbonyl, C1-6 alkylcarbonyloxy, C1-6 alkylhydroxymethyl, nitro, cyano, chloro, trifluoromethyl, C1-6 alkylsulphinyl, C1-6 alkylsulphonyl, C1-6 alkoxysulphinyl,C1-6 alkoxysulphonyl, C1-6 alkylcarbonylamino, C1-6 alkoxycarbonylamino, C1-6 alkyl-thiocarbonyl, C1-6 alkoxy-thiocarbonyl, C1-6 alkyl-thiocarbonyloxy, C1-6 alkyl-thiolmethyl, formyl or aminosulphinyl, aminosulphonyl or aminocarbonyl, the amino moiety being optionally substituted by one or two C1-6 alkyl groups, or C1-6 alkylsulphinylamino, C1-6 alkylsulphonylamino C1-6 alkoxysulphinylamino or C1-6 alkoxysulphonylamino or ethylenyl terminally substituted by C1-6 alkylcarbonyl, nitro or cyano, or --C(C1-6 alkyl)NOH or --C(C1-6 alkyl)NNH2, or one of R1 and R2 is nitro, cyano or C1-3 alkylcarbonyl and the other is methoxy or amino optionally substituted by one or two C1-6 alkyl or by C2-7 alkanoyl;
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- Benzopyrans
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Compounds of formula (I): STR1 wherein: one of R1 and R2 is hydrogen and the other is selected from the class of alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, alkylhydroxymethyl, nitro, cyano, chloro, trifluoromethyl, alkylsulphin
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