- Preparation method of high-temperature-resistant composite cross-linking agent
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The invention belongs to the technical field of preparation of crosslinking agents, and particularly relates to a preparation method of a high-temperature-resistant composite crosslinking agent, which comprises 20 - 40 parts of a zirconium oxychloride sol
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Paragraph 0044; 0055; 0061; 0072; 0078; 0089; 0095; 0106
(2021/06/22)
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- Selective Cross-Coupling of (Hetero)aryl Halides with Ammonia to Produce Primary Arylamines using Pd-NHC Complexes
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Herein we report the first example of (hetero)arylation of ammonia using a monoligated palladium-NHC complex. The new, rationally designed, precatalyst (DiMeIHeptCl)Pd(allyl)Cl featuring highly branched alkyl chains has been shown to be effective in selective aminations across a range of challenging substrates, including nitrogen-containing heterocycles and those featuring base-sensitive functionality. The less bulky Pd-PEPPSI-IPentCl precatalyst performs well for ortho-substituted aryl halides, giving monoarylated products in high yield with good selectivity.
- Lombardi, Christopher,Day, Jonathan,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Farmer, Jennifer L.,Organ, Michael G.
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supporting information
p. 251 - 254
(2017/04/26)
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- Palladium-catalyzed coupling of ammonia with aryl chlorides, bromides, iodides, and sulfonates: A general method for the preparation of primary arylamines
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We report that the complex generated from Pd[P(o-tol)3] 2 and the alkylbisphosphine CyPF-t-Bu is a highly active and selective catalyst for the coupling of ammonia with aryl chlorides, bromides, iodides, and sulfonates. The couplings of ammonia with this catalyst conducted with a solution of ammonia in dioxane form primary arylamines from a variety of aryl electrophiles in high yields. Catalyst loadings as low as 0.1 mol % were sufficient for reactions of many aryl chlorides and bromides. In the presence of this catalyst, aryl sulfonates also coupled with ammonia for the first time in high yields. A comparison of reactions in the presence of this catalyst versus those in the presence of existing copper and palladium systems revealed a complementary, if not broader, substrate scope. The utility of this method to generate amides, imides, and carbamates is illustrated by a one-pot synthesis of a small library of these carbonyl compounds from aryl bromides and chlorides, ammonia, and acid chlorides or anhydrides. Mechanistic studies show that reactions conducted with the combination of Pd[P(o-tol)3]2 and CyPF-t-Bu as catalyst occur with faster rates and higher yields than those conducted with CyPF-t-Bu and palladiun(II) as catalyst precursors because of the low concentration of active catalyst that is generated from the combination of palladium(II), ammonia, and base.
- Vo, Giang D.,Hartwig, John F.
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supporting information; scheme or table
p. 11049 - 11061
(2009/12/05)
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- Non-peptidic HIV protease inhibitors: C2-symmetry-based design of bis- sulfonamide dihydropyrones
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Potent, non-peptidic, dihydropyrone sulfonamide HIV protease inhibitors have been previously described. Crystallographic analysis of dihydropyrone sulfonamide inhibitor/HIV protease complexes suggested incorporation of a second, C2 symmetry-rel
- Janakiraman, Musiri N.,Watenpaugh, Keith D.,Tomich, Paul K.,Chong, Kong-Teck,Turner, Steve R.,Tommasi, Ruben A.,Thaisrivongs, Suvit,Strohbach, Joseph W.
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p. 1237 - 1242
(2007/10/03)
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- PYRANONE COMPOUNDS USEFUL TO TREAT RETROVIRAL INFECTIONS
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The present invention relates to compounds of formulae (I) and (II) which are pyran-2-ones, 5,6-dihydro-pyran-2-ones, 4-hydroxy-benzopyran-2-ones, 4-hydroxy-cycloalkyl[b]pyran-2-ones, and derivatives thereof, useful for inhibiting a retrovirus in a mammalian cell infected with said retrovirus, wherein R 10 and R 20 taken together are formulae (III) and (IV). STR1
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- Facile Hydrodehalogenation with H2 and Pd/C Catalyst under Multiphase Conditions. 2. Selectivity and Kinetics
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Hydrodehalogenation of polyhalogenated aromatics with Pd/C catalyst carried out in the presence of a quaternary onium salt follows zero-order kinetics in the substrate and first-order kinetics in the Pd/C catalyst; the related rate constants were determined for o-, m- and p-bromotoluenes, o-, m- and p-chloroalkylbenzenes (methyl, ethyl, and propyl derivatives), and other aryl halides.Reaction rates, depending on the aromatic to be reduced, may be strongly enhanced by the presence of quaternary onium salts: the isomeric chloroethylbenzenes were reduced 50 times faster when operating in the presence of Aliquat 336 (1).Also the hindered 2-chloro-m-xylene easily yielded m-xylene.The cocatalyst onium salts operate by being adsorbed on the Pd/C surface, as shown when kinetic constants are reported by varying the onium salt amount: classical Langmuir adsorption isotherms are observed.The presence of the onium salt may also influence selectivity in the reduction of isomeric aryl halides: when 1 is present, p-dichlorobenzene reacts in diethyl ether at 20 deg C, 5-fold slower than the ortho isomer; whereas the reduction rates of the two compounds are almost the same in its absence.
- Marques, Carlos Alberto,Selva, Maurizio,Tundo, Pietro
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p. 3830 - 3837
(2007/10/02)
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- 3' Cyanophenylalkanolamines: a contribution to the search for selective β adrenomimetic compounds
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Some derivatives of 1 (3' cyanophenyl) 2 aminoethanol have been synthesized in which OH is substituted at the nucleus, methyl or ethyl at the α carbon atom and isopropyl or t butyl at the nitrogen atom. The pharmacological research has shown that by combi
- Pratesi,Grana,Villa
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p. 753 - 765
(2007/10/06)
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