- Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
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An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
- Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
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supporting information
p. 17887 - 17896
(2020/08/19)
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- Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts
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An efficient synthesis of methoxy-substituted thioxanthylium salts has been developed. The reaction of diaryl sulfides with benzoyl chlorides in the presence of TfOH smoothly proceeded to give the desired thioxanthylium salts in good yields. In their UV–vis spectra, the maximum absorption wavelengths of methoxy-functionalized thioxanthylium salts were observed at around 460 nm, which show a drastic red shift compared to the parent thioxanthylium salts. The present reaction provides a versatile access to functionalized thioxanthylium salts, and therefore it constitutes a promising tool for the synthesis of biologically and photochemically active molecules.
- Tanaka, Kenta,Tanaka, Yuta,Kishimoto, Mami,Hoshino, Yujiro,Honda, Kiyoshi
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p. 2105 - 2112
(2019/09/30)
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- Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
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Current methods for functional group interconversion have, for the most part, relied on relatively strong driving forces which often require highly reactive reagents to generate irreversibly a desired product in high yield and selectivity. These approaches generally prevent the use of the same catalytic strategy to perform the reverse reaction. Here we describe a catalytic functional group metathesis approach to interconvert, under CO-free conditions, two synthetically important classes of electrophiles that are often employed in the preparation of pharmaceuticals and agrochemicals—aroyl chlorides (ArCOCl) and aryl iodides (ArI). Our reaction design relies on the implementation of a key reversible ligand C–P bond cleavage event, which enables a non-innocent, metathesis-active phosphine ligand to mediate a rapid aryl group transfer between the two different electrophiles. Beyond enabling a practical and safer approach to the interconversion of ArCOCl and ArI, this type of ligand non-innocence provides a blueprint for the development of a broad range of functional group metathesis reactions employing synthetically relevant aryl electrophiles.
- Lee, Yong Ho,Morandi, Bill
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p. 1016 - 1022
(2018/09/06)
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- Functional Group Transposition: A Palladium-Catalyzed Metathesis of Ar-X σ-Bonds and Acid Chloride Synthesis
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We describe the development of a new method to use palladium catalysis to form functionalized aromatics: via the metathesis of covalent σ-bonds between Ar-X fragments. This transformation demonstrates the dynamic nature of palladium-based oxidative addition/reductive elimination and offers a straightforward approach to incorporate reactive functional groups into aryl halides through exchange reactions. The reaction has been exploited to assemble acid chlorides without the use of high energy halogenating or toxic reagents and, instead, via the metathesis of aryl iodides with other acid chlorides.
- De La Higuera Macias, Maximiliano,Arndtsen, Bruce A.
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supporting information
p. 10140 - 10144
(2018/08/23)
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- Acid Chloride Synthesis by the Palladium-Catalyzed Chlorocarbonylation of Aryl Bromides
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We report a palladium-catalyzed method to synthesize acid chlorides by the chlorocarbonylation of aryl bromides. Mechanistic studies suggest the combination of sterically encumbered PtBu3 and CO coordination to palladium can rapidly equilibrate the oxidative addition/reductive elimination of carbon-halogen bonds. This provides a useful method to assemble highly reactive acid chlorides from stable and available reagents, and can be coupled with subsequent nucleophilic reactions to generate new classes of carbonylated products. The Good, the Bad and the Bulky! By employing a sterically encumbered phosphine ligand, tri-tert-butyl phosphine, under palladium catalysis inert aryl bromides are chlorocarbonylated to create reactive acid chlorides by reversible carbon-halogen bond reductive elimination. This general platform allows for an expanded scope of the Heck carbonylation reaction to include previously incompatible nucleophiles.
- Quesnel, Jeffrey S.,Kayser, Laure V.,Fabrikant, Alexander,Arndtsen, Bruce A.
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supporting information
p. 9550 - 9555
(2015/06/30)
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- Cu(II)-mediated C-H amidation and amination of arenes: Exceptional compatibility with heterocycles
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A Cu(OAc)2-mediated C-H amidation and amination of arenes and heteroarenes has been developed using a readily removable directing group. A wide range of sulfonamides, amides, and anilines function as amine donors in this reaction. Heterocycles present in both reactants are tolerated, making this a broadly applicable method for the synthesis of a family of inhibitors including 2-benzamidobenzoic acids and N-phenylaminobenzoates.
- Shang, Ming,Sun, Shang-Zheng,Dai, Hui-Xiong,Yu, Jin-Quan
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supporting information
p. 3354 - 3357
(2014/03/21)
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- A palladium-catalyzed carbonylation approach to acid chloride synthesis
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We describe a new approach to acid chloride synthesis via the palladium-catalyzed carbonylation of aryl iodides. The combination of sterically encumbered phosphines (PtBu3) and CO coordination has been found to facilitate the rapid carbonylation of aryl iodides into acid chlorides via reductive elimination from (tBu3P)(CO) Pd(COAr)Cl. The formation of acid chlorides can also be exploited to perform traditional aminocarbonylation reactions under exceptionally mild conditions (ambient temperature and pressure), and with a range of weakly nucleophilic substrates.
- Quesnel, Jeffrey S.,Arndtsen, Bruce A.
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supporting information
p. 16841 - 16844
(2013/12/04)
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- Method for preparing a benzylic-type ether
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The invention concerns a method for preparing a benzylic-type ether from an aromatic compound. The inventive method for preparing a benzylic-type ether from an aromatic compound is characterised in that it consists in: in a first step, acylating an aromatic compound by reacting said aromatic compound with an acylating agent, in the presence of an efficient amount of zeolite or a Friedel-Crafts catalyst leading to a ketonic compound; in a second step, reducing the carbonyl group into carbinol leading to a benzylic alcohol; in a third step, etherifying the hydroxyl group, by reacting the benzylic alcohol with another alcohol, in the presence of an efficient amount of zeolite.
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- Monomeric bile acid derivatives, processes for their preparation and the use of these compounds as medicaments
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Monomeric bile acid derivatives, processes for their preparation and the use of these compounds as medicaments Monomeric bile acid derivatives of the formula I in which GS, X and Z have the meanings given, and processes for their preparation are described. The compounds have useful pharmacological properties and can therefore be used as medicaments.
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- N-cyanoalkyl-N-haloalkylthio carboxamides as fungicides
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N-cyanoalkyl-N-haloalkylthio alkyl-, aryl- and aralkyl-carboxamides of the general formula: STR1 wherein R is alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, lower alkenyl of 2 to 6 carbon atoms or lower alkynyl of 2 to 6 carbon atoms, all optionally substituted with 1 to 4 halogen atoms; lower alkoxyalkylene; aryl of 6 to 12 carbon atoms; aralkyl of 7 to 16 carbon atoms; or substituted aryl or substituted aralkyl both substituted with 1 to 3 substituents independently selected from phenyl, lower alkyl of 1 to 6 carbon atoms, lower alkoxy of 1 to 6 carbon atoms, lower alkylthio of 1 to 6 carbon atoms, halogen, nitro, cyano, STR2 wherein R4 is hydrogen or lower alkyl of 1 to 6 carbon atoms, STR3 wherein R5 and R6 are independently hydrogen or lower alkyl of 1 to 6 carbon atoms; R1 and R2 are independently hydrogen, or lower alkyl of 1 to 6 carbon atoms; and R3 is alkyl of 1 to 3 carbon atoms substituted with 3 to 6 halogen atoms or trihalovinyl are fungicidal.
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- Process for preparing amides by reaction in presence of molecular sieve
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There is provided a process for preparing amides which comprises reacting an amine, or an amide, and an acid halide, or anhydride, in suitable molecular proportions, in an inert organic diluent, in the presence of an effective amount of a molecular sieve, until the reaction is completed, separating the molecular sieve, and recovering the amide from the organic mother liquor.
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