- Copper-Mediated, Heterogeneous, Enantioselective Intramolecular Buchner Reactions of α-Diazoketones Using Continuous Flow Processing
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Enantioselective intramolecular Buchner reactions of α-diazoketones can be effected using heterogeneous copper-bis(oxazoline) catalysts in batch or using continuous flow processing in up to 83% ee. The catalyst can be reused up to 7 times without loss of activity. For α-diazoketones 3 and 4, the enantioselection achieved in flow with the immobilized catalyst was comparable with the standard homogeneous catalyzed process.
- Crowley, Daniel C.,Lynch, Denis,Maguire, Anita R.
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p. 3794 - 3805
(2018/04/14)
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- Potassium Channel Modulators
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Disclosed herein are KCNQ potassium channels modulators of formula (I) wherein R1, R2, R3, R4, and R5 are as defined in the specification. Compositions comprising such compounds; and methods for treating conditions and disorders using such compounds and compositions are also described.
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Page/Page column 39
(2012/05/21)
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- Preparation of α-amino acids by oxidative oxazoline-oxazinone rearrangement-hydrogenation (OOOH). Scope and limitations
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The range and scope of the oxidative oxazoline-oxazinone rearrangement-hydrogenation sequence (OOOH)-a short, direct asymmetric synthesis of α-amino acids from carboxylic acids-was explored. The highest yet reported diastereoselectivity for hydrogenation of the oxazinone C=N bond (d.r.=>80:1) is disclosed and rationalized with the aid of ab initio molecular calculations.
- Liu, Chaomin,Molinski, Tadeusz F.
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supporting information; experimental part
p. 2022 - 2027
(2011/11/29)
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- NOVEL BENZAMIDE DERIVATIVES AS MODULATORS OF THE FOLLICLE STIMULATING HORMONE
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The present invention provides new compounds of formula I, wherein Q, R1, R2, R4, R5, R6, Xi, R7, R8, M and G1 nare defined as in formula I; invention compounds are modulators of follicle-stimulating hormone - ("FSH") which are useful for male and female contraception as well as other disorders modulated by FSH receptor.
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- Pyrazolopyrimidines as therapeutic agents
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The present invention is directed to pyrazolopyrimidine derivatives of formula (I) wherein the substituents are defined herein, which are useful as kinase inhibitors and as such are useful for affecting angiogenesis and diseases and conditions associated with angiogenesis.
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- Pyrazolopyrimidines as therapeutic agents
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The present invention provides compounds of Formula I, including pharmaceutically acceptable salts and/or prodrugs thereof, where G, R2, and R3 are defined as described herein.
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- Rhodium chemzymes: Michaelis-Menten kinetics in dirhodium(II) carboxylate-catalyzed carbenoid reactions
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Rhodium carboxylate-mediated reactions of diazoketones involving cyclopropanation, C-H insertion, and aromatic C-C double bond addition/electrocyclic ring opening obey saturation (Michaelis-Menten) kinetics. Axial ligands for rhodium, including aromatic hydrocarbons and Lewis bases such as nitriles, ethers, and ketones, inhibit these reactions by a mixed kinetic inhibition mechanism, meaning that they can bind both to the free catalyst and to the catalyst - substrate complex. Substrate inhibition can also be exhibited by diazocompounds bearing these groupings in addition to the diazo group. The analysis of inhibition shows that the active catalyst uses only one of its two coordination sites at a time for catalysis. Some ketones exhibit the interesting property that they selectively bind to the catalyst - substrate complex. The similarity of the kinetic constants from different types of reactions with similar diazoketones, regardless of the linking unit or the environment of the reacting alkene, suggests that the rate-determining step is the generation of the rhodium carbenoid. A very useful rhodium carboxylate catalyst for asymmetric synthesis, Rh2(DOSP)4, shows slightly slower kinetic parameters than the achiral catalysts, implying that enantiose-lectivity of this catalyst is based on slowing reactions from one of the enantiotopic faces of the reactant, rather than any type of ligand-accelerated catalysis. A series of rhodium catalysts derived from acids with pKas spanning 4 orders of magnitude give very similar kinetic constants.
- Pirrung, Michael C.,Liu, Hao,Morehead Jr., Andrew T.
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p. 1014 - 1023
(2007/10/03)
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- Reactivity of 1,3-di-tert-butylaziridinones with phenyl substituents. A new fragmentation of α-lactams
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Several isolable aziridinones with bulky substituents were prepared and their reactions with nucleophiles, i.e., methanol, sodium methoxide and benzylamine, were investigated. A novel fragmentation of aziridinones having a phenyl group on the C3 moiety was found.
- Shimazu, Masako,Endo, Yasuyuki,Shudo, Koichi
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p. 735 - 744
(2007/10/03)
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