- Hydrazines and azides via the metal-catalyzed hydrohydrazination and hydroazidation of olefins
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The discovery, study, and implementation of the Co- and Mn-catalyzed hydrohydrazination and hydroazidation reactions of olefins are reported. These reactions are equivalent to direct hydroaminations of C-C double bonds with protected hydrazines or hydrazoic acid but are based on a different concept in which the H and the N atoms come from two different reagents, a silane and an oxidizing nitrogen source (azodicarboxylate or sulfonyl azide). The hydrohydrazination reaction using di-tert-butyl azodicarboxylate is characterized by its ease of use, large functional group tolerance, and broad scope, including mono-, di-, tri-, and tetrasubstituted olefins. Key to the development of the hydroazidation reaction was the use of sulfonyl azides as nitrogen sources and the activating effect of tert-butyl hydroperoxide. The reaction was found to be efficient for the functionalization of mono-, di-, and trisubstituted olefins, and only a few functional groups are not tolerated. The alkyl azides obtained are versatile intermediates and can be transformed to the free amines or triazoles without isolation of the azides. Preliminary mechanistic investigations suggest a rate-limiting hydrocobaltation of the alkene, followed by an amination reaction. Radical intermediates cannot be ruled out and may be involved.
- Waser, Jerome,Gaspar, Boris,Nambu, Hisanori,Carreira, Erick M.
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p. 11693 - 11712
(2007/10/03)
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- One-step conversion of pyridine N-oxides to tetrazolo[1,5-a]pyridines
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(Chemical Equation Presented) Pyridine N-oxides were converted to tetrazolo[1,5-a]pyridines in good to excellent yield by heating in the presence sulfonyl or phosphoryl azides and pyridine in the absence of solvent. Various sulfonyl and phosphoryl azides were screened for reactivity under a standard set of conditions. Diphenyl phosphorazidate was the most convenient reagent and gave high yields. Reaction optimization, scope, and scalability are discussed.
- Keith, John M.
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p. 9540 - 9543
(2007/10/03)
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- Delivery of a substance to a pre-determinated site
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The invention is concerned with delivery vehicles for delivering a substance of interest to a predetermined site, said vehicle comprising said substance and a means for inducing availability of at least one compartment of said vehicle toward the exterior, thereby allowing access of said substance to the exterior of said vehicle at said predetermined site. The invention is further concerned with uses of said vehicle and methods for preparing it.
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- COMPOUNDS AND METHODS
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This invention relates to libraries of non-peptide compounds each comprised of a core structure and methods for making such libraries. This invention also relates to novel silicon-based polymer resins and silane linkers, methods for their preparation and their use in the synthesis of libraries of compounds to be screened as pharmaceutical agents.
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- Microspheres of diamide-dicarboxylic acids
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Diamide-dicarboxylic acid microspheres are provided. The diamide-dicarboxylic acids may be combined with active agent(s). The resultant composition may be in microsphere form. Also disclosed are methods for administering the microsphere and/or composition that includes the active agent. The microsphere, with or without active agent, may be prepared by (A) solubilizing, in a solvent, at least one diamide-dicarboxylic acid, to yield a first solution; and (B) contacting the first solution with a precipitator solution in which the diamide-carboxylic acid is insoluble and optionally with an active agent.
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- Multicatalytic protease inhibitors
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Disclosed herein are inhibitors of the multicatalytic protease enzyme which are represented by the general formula: STR1 Constituent members and preferred constituent members are disclosed herein. Methodologies for making and using the disclosed compounds are also set forth herein.
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- PERHYDROTHIAZEPINE DERIVATIVES, THEIR PREPARATION AND THEIR THERAPEUTIC USE
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Compounds of formula (I): STR1 (wherein: R 1 represents an optionally substituted alkyl, cycloalkyl, aryl, partially hydrogenated aryl or heterocyclic group; R 2, R 3, R 4 and R. sup.5 represent hydrogen or an optionally substituted alkyl, cycloalkyl, aralkyl, aryl, heterocyclic or heterocyclic-alkyl group or any adjacent pair thereof form a cyclic structure, at least one not being hydrogen; A represents a bond, or a methylene, ethylene, oxymethyl or thiomethyl group; B represents an alkylene, alkylidene, cycloalkylene or cycloalkylidene group; and n is 0, 1 or 2) and salts and esters thereof are hypotensive agents.
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- New methods and reagents in organic synthesis. 35. A new synthesis of some non-steroidal anti-inflammatory agents with the 2-arylpropionic acid skeleton by the use of diphenyl phosphorazidate (DPPA) as a 1,3-dipole
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Reaction of diphenylphosphonic azide (8) with the pyrrolidine enamine 13 of 4-isobutylpropiophenone afforded two amidines 15a and 16a, which were derived from the 1,3-dipolar cycloadduct 14a by the expulsion of nitrogen followed by 1,2-aryl migration (path a) and by 1,3-dipolar elimination (path b), respectively. Although diphenylthiophosphinic azide (9) and ethyl phenylthiophosphonoazidate (10) also gave similar results, diphenylphosphorazidate (DPPA, (C6H5O)2P(O)N3) furnished the amidine 15d formed via path a as the sole isolable product. Hydrolysis of 15d with potassium hydroxide afforded ibuprofen (3) in good yield. Other nonsteroidal antinflammatory agents, naproxene (4), ketoprofen (5), and flurbiprofen (6), were analogously and conveniently prepared from the ketones 17, 22, and 25, respectively, by a similar three-step operation using pyrrolidine, DPPA, and potassium hydroxide. 2-(2-Dibenzofuranyl)-propionic acid (7) was also prepared from the ketone 28 by the three-step procedure.
- Kawai,Kato,Hamada,Shioiri
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p. 3139 - 3148
(2007/10/02)
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- DIARYLPHOSPHINIC AZIDES. PHOTOCHEMICAL REACTIONS INCLUDING REARRANGEMENT IN METHANOL
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On photolysis in methanol the diarylphosphinic azides Ar2P(O)N3 (Ar=phenyl, p-tolyl, p-anisyl, p-chlorophenyl) rearrange with loss of nitrogen to form (monomeric) metaphosphonimidates which are trapped by the solvent to give methyl NP-diarylphosphonamidates (7) (41-53percent).Diarylphosphinic amides (18-42percent) are also usually formed, presumably from (triplet) nitrenes.The limited evidence available suggests that the rearrangements take place directly from the photo-excited azides rather than via (singlet) nitrene intermediates.One of the products of rearrangement, methyl NP-di(p-chlorophenyl)phosphonamidate, suffers extensive photochemical dechlorination giving methyl N-phenyl-P-p-chlorophenylphosphonamidate.
- Harger, Martin J.P.,Westlake, Sally
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p. 1511 - 1516
(2007/10/02)
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