- Ligand-free palladium catalysis of the Suzuki reaction in water using microwave heating
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(figure presented) We report the ligand-free palladium catalysis of the Suzuki reaction in water using microwave heating. Our methodology uses low palladium loadings (0.4 mol %), is fast (5-10 min reaction time), and is useful for couplings involving boronic acids and aryl iodides, bromides, and chlorides.
- Leadbeater, Nicholas E.,Marco, Maria
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- Organic Solvent-Free, Pd(II)-Salan Complex-Catalyzed Synthesis of Biaryls via Suzuki-Miyaura Cross-Coupling in Water and Air
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With use of a Pd(II)-sulfosalan complex as a water-soluble catalyst, we have developed an efficient synthesis of biaryls via Suzuki-Miyaura cross-coupling in water under aerobic conditions. The water-insoluble target molecules were isolated by simple filtration in analytical purity after washing with 0.01 M aqueous HCl (20 examples). In most cases, palladium contamination was below 5 ppm considered acceptable for active pharmaceutical ingredients. The established method is scalable, reproducible, and provides biaryl products in isolated yields up to 91%.
- Bunda, Szilvia,Udvardy, Antal,Voronova, Krisztina,Joó, Ferenc
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- A liquid-phase approach to functionalized janus dendrimers: Novel soluble supports for organic synthesis
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A new kind of functionalized Janus dendrimer has been synthesized via a liquid-phase approach, which could easily be purified using a simple precipitation method without the need for chromatographic separation. Their use for liquid-phase organic synthesis has been achieved in the Pd-catalyzed Suzuki coupling reactions, giving biaryl products in excellent yields after cleavage.
- Feng, Yu,He, Yan-Mei,Zhao, Li-Wen,Huang, Yi-Yong,Fan, Qing-Hua
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- An efficient protocol for the palladium-catalysed Suzuki-Miyaura cross-coupling
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The palladacyclic catalyst precursor received by ortho-palladation of ([1,1′-biphenyl]-2-yloxy)diisopropyl-phosphine represents a highly active system for Suzuki-Miyaura cross-coupling reactions when used in neat water. An efficient, broadly applicable and sustainable aqueous protocol was developed using 2.5 eq. of Na2CO3 as base, allowing the reaction to be performed under air and at ambient temperature with Pd loadings of 0.04 mol%. Coupling products are obtained in high yields and excellent purity by simple filtration with no organic solvents needed throughout the whole reaction. A broad variety of functional groups are tolerated and a large number of substrates can be applied with this protocol. The crystal structure of the palladacyclic catalyst precursor is presented as well as investigations targeting the nature of catalyst activation and the active catalytic species.
- Marziale, Alexander N.,Jantke, Dominik,Faul, Stefan H.,Reiner, Thomas,Herdtweck, Eberhardt,Eppinger, Joerg
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- A general approach to N-heterocyclic carbenes with a fused tetracyclic core: Ligands for suzuki-miyaura cross-coupling reaction
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The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading. Copyright
- Sutar, Revannath L.,Kumar, Vinod,Shingare, Rahul D.,Thorat, Shridhar,Gonnade, Rajesh,Reddy, D. Srinivasa
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- Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance
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Water-soluble salan ligands were synthesized by hydrogenation and subsequent sulfonation of salens (N,N’-bis(slicylidene)ethylenediamine and analogues) with various bridging units (linkers) connecting the nitrogen atoms. Pd (II) complexes were obtained in reactions of sulfosalans and [PdCl4]2?. Characterization of the ligands and complexes included extensive X-ray diffraction studies, too. The Pd (II) complexes proved highly active catalysts of the Suzuki–Miyaura reaction of aryl halides and arylboronic acid derivatives at 80 ?C in water and air. A comparative study of the Pd (II)–sulfosalan catalysts showed that the catalytic activity largely increased with increasing linker length and with increasing steric congestion around the N donor atoms of the ligands; the highest specific activity was 40,000 (mol substrate) (mol catalyst × h)?1. The substrate scope was explored with the use of the two most active catalysts, containing 1,4-butylene and 1,2-diphenylethylene linkers, respectively.
- Bunda, Szilvia,Joó, Ferenc,Kathó, ágnes,Udvardy, Antal,Voronova, Krisztina
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supporting information
(2020/09/18)
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- Synthesis of water soluble Pd-Piperidoimidazolin-2-ylidene complexes and their catalytic activities in neat water
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Through the strategy of water soluble N-heterocyclic carbene (NHC) ligand, Pd-catalyzed reactions were developed in aqueous media. Therefore, four new piperidoimidazolinium salts (1a-d) consisting of sulfonate (a), esther (b, c) and carboxylic acid (d) functionalities and their water-soluble Pd-NHC complexes (2a-d) were synthesized. The new compounds were characterized by elemental analysis, FTIR, TGA, UV–vis and NMR spectroscopy. The catalytic activities of water soluble Pd-NHC complexes (2a-d) were investigated using the Suzuki-Miyaura (S-M) reaction and the reduction of nitroarenes. We found that the water-soluble polar or ionic groups on piperidoimidazolin-2-ylidine had an effect on the catalytic activity. The water-soluble catalyst can be recycled efficiently and reused six times with only a very slight loss of catalytic activity.
- ?ak?r, Sinem,Türkmen, Hayati
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- PdEDTA held in an ionic liquid brush as a highly efficient and reusable catalyst for Suzuki reactions in water
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(Chemical Equation Presented) An efficient and reusable catalyst with PdEDTA immobilized in an ionic liquid brush and a green procedure have been developed for coupling aryl iodides and bromides with phenylboronic acid. These reactions were conducted in water under aerobic conditions with water-insoluble or even solid aryl halides. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability. There was no apparent loss of catalyst efficiency until the 10th cycle.
- Wei, Jun-Fa,Jiao, Jiao,Feng, Jin-Juan,Lv, Jing,Zhang, Xi-Ru,Shi, Xian-Ying,Chen, Zhan-Guo
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supporting information; experimental part
p. 6283 - 6286
(2009/12/24)
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- Solid-phase Suzuki cross-coupling reactions using a phosphine ligand based on a phospha-adamantane framework
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The use of a catalyst system based on Pd2dba3· CHCl3 and 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phenyl-6-phospha- adamantane allows for Suzuki coupling aryl halides with an array of boronic acids on a solid-phase platform. The reactions can be carried out at room temperature with low palladium loadings in high yields.
- Ohnmacht, Stephan A.,Brenstrum, Tim,Bleicher, Konrad H.,McNulty, James,Capretta, Alfredo
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p. 5661 - 5663
(2007/10/03)
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- N-acylsulfonamide apoptosis promoters
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N-Benzoyl arylsulfonamides having the formula are BCL-Xl inhibitors and are useful for promoting apoptosis. Also disclosed are BCL-Xl inhibiting compositions and methods of promoting apoptosis in a mammal.
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- N-Acylsulfonamide apoptosis promoters
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N-Benzoyl arylsulfonamides having the formula Are BCL-X1 inhibitors and are useful for promoting apoptosis. Also disclosed are BCL-X1 inhibiting compositions and methods of promoting apoptosis in a mammal.
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- 2-(BIPHENYL-4-YL)-5-PHENYL-1,3,4-OXADIAZOLE (PBD): ELECTROPHILIC 4'-SUBSTITUTION AND FOLLOWING TRANSFORMATIONS
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PBD was converted into 4'-substituted derivatives I-XII using usual electrophilic reagents.The decompositions of PBD, 4'-acetyl derivative I and 4'-nitro derivative VI with hydroiodic acid gave 4'-substituted 4-biphenylcarboxylic acids XIIIa-XIIIc and benzoic acid, respectively.The regioselectivity of the reactions was also proved by means of high resolution NMR spectroscopy.
- Kurfuerst, Antonin,Lhotak, Pavel,Nadenik, Petr,Raclova-Pavlikova, Frantiska,Kuthan, Josef
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p. 1495 - 1504
(2007/10/02)
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- AROYLNITRENES WITH SINGLET GROUND STATES: PHOTOCHEMISTRY OF ACETYL-SUBSTITUTED AROYL AND ARYLOXYCARBONYL AZIDES
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The photochemistry of 4-acetylbenzoyl azide (ABA), 4-acetyl-4'-biphenoyl azide (ADA), and 4-acetylphenoxycarbonyl azide (APA) shows unusual wavelength and structrural effects.Irradiation of ABA or ADA into their ?-?* bands with deep-UV light leads to formation of 4-acetylbenzoylnitrene (ABN) and 4-acetyl-4'-biphenylnitrene (ADN), respectively, in competition with photo-Curtis rearrangement to form isocyanates.Irradiation of these azides into their n-?* bands with near-UV light gives only the aroylnitrenes.The triplet excited states of the azides were detected chemically and by transient spectroscopic techniques.Nitrogen loss following near-UV irradiation occurs exclusively from the excited triplet azides.However, the chemical properties of ABN and ADN are consistent only with reactions originating from their singlet states.An ESR spectrum is observed at 8 K for ((4-acetylphenoxy)carbonyl)nitrene (APN) but not for 4-acetylbenzoylnitrene (ABN) of 4-acetyl-4'-biphenylcarbonylnitrene (ADN).The chemical properties of APN in tert-butyl alcohol show that its triplet is no more than 5 kcal/mol below its lowest single state.In contrast, the chemical properties of ABN and ADN indicate that these niterenes have singlet ground states.
- Sigman, Michael E.,Autrey, Tom,Schuster, Gary B.
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p. 4297 - 4305
(2007/10/02)
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