- Synthesis and Catalytic Use of Gold(I) Complexes Containing a Hemilabile Phosphanylferrocene Nitrile Donor
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Removal of the chloride ligand from [AuCl(1-κP)] (2) containing a P-monodentate 1′-(diphenylphosphanyl)-1-cyanoferrocene ligand (1), by using silver(I) salts affords cationic complexes of the type [Au(1)]X, which exist either as cyclic dimers [Au(1)]2X2 (3a, X=SbF6; 3 c, X=NTf2) or linear coordination polymers [Au(1)]nXn (3 a′, X=SbF6; 3 b′, X=ClO4), depending on anion X and the isolation procedure. As demonstrated for 3 a′, the polymers can be readily cleaved by the addition of donors, such as Cl-, tetrahydrothiophene (tht) or 1, giving rise to the parent compound 2, [Au(tht)(1-κP)][SbF6] (5 a) or [Au(1-κP)2][SbF6] (4 a), respectively, of which the last two compounds can also be prepared by stepwise replacement of tht in [Au(1-κP)2][SbF6]. The particular combination of a firmly coordinated (phosphane) and a dissociable (nitrile) donor moieties renders complexes 3/3′ attractive for catalysis because they can serve as shelf-stable precursors of coordinatively unsaturated AuI fragments, analogous to those that result from the widely used [Au(PR3)(RCN)]X catalysts. The catalytic properties of the Au-1 complexes were evaluated in model annulation reactions, such as the synthesis of 2,3-dimethylfuran from (Z)-3-methylpent-2-en-4-yn-1-ol and oxidative cyclisation of alkynes with nitriles to produce 2,5-disubstituted 1,3-oxazoles. Of the compounds tested (2, 3 a′, 3 b′, 3 a, 4 a and 5 a), the best results were consistently achieved with dimer 3 c, which has good solubility in organic solvents and only one firmly bound donor at the gold atom. This compound was advantageously used in the key steps of annuloline and rosefuran syntheses.
- ?koch, Karel,Císa?ová, Ivana,?těpni?ka, Petr
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supporting information
p. 15998 - 16004
(2015/11/03)
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- Wittig Olefination Using Phosphonium Tetraphenylborate in the Absence of Additional Base
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The thermal decomposition of (substituted methyl)triphenylphosphonium tetraphenylborates, which can also be generated in situ from the corresponding phosphonium halide and NaBPh4, with an aldehyde affords olefins in 22-100% yields. This Wittig olefination does not need use additional base to form phosphorus ylide, and is highly tolerant of benzoic acid.
- Huang, Wenhua,Zhao, Shuang-Hong,Dong, Guang-Ping
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supporting information
p. 1802 - 1810
(2015/10/29)
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- PROCESS FOR THE SYNTHESIS OF (2E)-3-(3,4-DIMETHOXYPHENYL)PROP-2-ENENITRILE, AND APPLICATION IN THE SYNTHESIS OF IVABRADINE AND ADDITION SALTS THEREOF WITH A PHARMACEUTICALLY ACCEPTABLE ACID
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Process for the synthesis of the compound of formula (I): Application in the synthesis of ivabradine, addition salts thereof with a pharmaceutically acceptable acid and hydrates thereof.
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Paragraph 0030-0032
(2014/05/20)
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- PROCESS FOR THE SYNTHESIS OF 3-(2-BROMO-4,5-DIMETHOXYPHENYL)PROPANENITRILE, AND APPLICATION IN THE SYNTHESIS OF IVABRADINE AND ADDITION SALTS THEREOF WITH A PHARMACEUTICALLY ACCEPTABLE ACID
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Process for the synthesis of the compound of formula (I): Application in the synthesis of ivabradine, addition salts thereof with a pharmaceutically acceptable acid and hydrates thereof.
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Paragraph 0038-0040
(2014/05/07)
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- A biocompatible alkene hydrogenation merges organic synthesis with microbial metabolism
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Organic chemists and metabolic engineers use orthogonal technologies to construct essential small molecules such as pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small-molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Reported herein is a method for alkene hydrogenation which utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe, and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering. Reduction to practice: A hydrogenation reaction has been developed that employs hydrogen generated in situ by a microorganism and a biocompatible palladium catalyst to reduce alkenes on a synthetically useful scale. This type of transformation, which directly combines tools from organic chemistry with the metabolism of a living organism for small-molecule production, represents a new strategy for chemical synthesis.
- Sirasani, Gopal,Tong, Liuchuan,Balskus, Emily P.
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supporting information
p. 7785 - 7788
(2014/08/05)
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- Total synthesis of (+)-virgatusin via AlCl3-catalyzed [3+2] cycloaddition
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The AlCl3-catalyzed cycloaddition of a donor-acceptor (don-acc) cyclopropane and piperonal succinctly provides the core of virgatusin in a selective, high-yielding manner. The Royal Society of Chemistry 2009.
- Sanders, Shanina D.,Ruiz-Olalla, Andrea,Johnson, Jeffrey S.
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supporting information; experimental part
p. 5135 - 5137
(2009/12/08)
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- Total synthesis of siphonazole and its O-methyl derivative, structurally unusual bis-oxazole natural products
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The details of the first syntheses of the unusual bis-oxazole natural products siphonazole and its O-methyl derivative are reported. The cinnamyl substituted oxazole was constructed using diazocarbonyl chemistry, whereby the cinnamamide was reacted with the rhodium carbene derived from methyl 2-diazo-3-oxobutanoate to give a β-ketoamide that was cyclodehydrated to the corresponding oxazole-4-ester. Reduction to the corresponding aldehyde was followed by coupling with a zinc reagent derived from methyl 2-iodomethyl-5-methyloxazole-4-carboxylate, also prepared using rhodium carbene chemistry, to give, after oxidation of the resulting secondary alcohol, the desired bis-oxazole ketone. The syntheses were completed by hydrolysis of the ester and coupling of the 2,4-pentadienylamine side chain. The 2008 Royal Society of Chemistry.
- Linder, Joerg,Blake, Alexander J.,Moody, Christopher J.
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supporting information; experimental part
p. 3908 - 3916
(2009/06/28)
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- TOTAL SYNTHESIS OF SCELETIUM (AIZOACEAE) ALKALOIDS. THE CINNAMONITRILE ROUTE. THE TOTAL SYNTHESIS OF RACEMIC O-METHYL JOUBERTIAMINE AND MESEMBRINE
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A new method of synthesis of Sceletium (Aizoaceae) alkaloids based on the introduction of a "formyl anion" equivalent at the β-position of a cinnamonitrile, followed by Robinson annulation and final modification of the resulting cyanomethyl side is described.The method has been succesfully applied to the total synthesis of racemic O-methyljoubertiamine (1) and mesembrine (2).
- Sanchez, Ignacio H.,Tallabs, F. Ramon
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p. 891 - 894
(2007/10/02)
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