51264-60-9Relevant academic research and scientific papers
Gold catalysed Suzuki-Miyaura coupling of arenediazonium o-benzenedisulfonimides
Barbero, Margherita,Dughera, Stefano
, p. 5758 - 5769 (2018/09/10)
Arenediazonium o-benzenedisulfonimides have been used as efficient electrophilic partners in Au(I) catalysed Suzuki coupling reactions. The synthetic protocol is general, easy and produced either biaryls or heteroaryl arenes in good yields (51 positive examples, average yield 80%). o-Benzenedisulfonimide was recovered at the end of the reactions and was reused to prepare the starting salts for further reactions. Mechanistic insights suggest that the o-benzenedisulfonimide anion act as an electron transfer agent and promotes a catalytic cycle which does not require the presence of photocatalysts or external oxidants.
Rapid threefold cross-couplings with sterically bulky triarylbismuths under Pd-Cu dual catalysis
Rao, Maddali L. N.,Dhanorkar, Ritesh J.
, p. 1012 - 1017 (2016/01/16)
The threefold cross-coupling reactivity of sterically highly demanding bulky triarylbismuths was addressed with task specific Pd-Cu dual catalytic conditions. In this study, an unprecedented hitherto unknown cross-coupling reactivity of sterically bulky triarylbismuths was demonstrated with a diverse range of aryl iodides and bromides. The intermediacy and in situ formation of arylcopper was probed with mesitylcopper in support of the proposed dual catalysis. This study opened up an easy way forward for application of sterically bulky bismuth reagents in threefold aryl-aryl coupling reactions.
Synthesis, characterization, and catalytic activity of nickel(II) alkyl complexes supported by pyrrole-diphosphine ligands
Venkanna, Gopaladasu T.,Tammineni, Swetha,Arman, Hadi D.,Tonzetich, Zachary J.
, p. 4656 - 4663 (2013/09/23)
The organometallic Ni(II) chemistry of the pyrrole-based pincer ligands (P2RPyr)- (P2RPyr = 2,5-(R2PCH2)2C4H2N, R = Ph, Cy) is reported. Reactions of Grignard reagents with [NiCl(P 2RPyr)] afford a variety of alkyl and aryl complexes (methyl, ethyl, benzyl, phenyl, and allyl) that all display square-planar geometries about nickel. The hydride complex [NiH(P2 CyPyr)] can also prepared either through treatment of [NiCl(P 2CyPyr)] with LiHBEt3 or by reaction of H(P2RPyr) with [Ni(COD)2] (COD = 1,4-cyclooctadiene). Reactions of the methyl and hydride complexes with CO and CO2, respectively, evince clean migratory insertion chemistry of the Ni-C and Ni-H bonds. Both the alkyl and chloride complexes are active catalysts for the Kumada coupling of aryl chlorides and aryl or alkyl Grignard reagents at room temperature. The solid-state structures of several of the complexes are reported.
Biaryl and aryl ketone synthesis via Pd-catalyzed decarboxylase coupling of carboxylate salts with aryl triflates
Goossen, Lukas J.,Linder, Christophe,Rodriguez, Nuria,Lange, Paul P.
supporting information; experimental part, p. 9336 - 9349 (2010/04/03)
A bimetallic catalyst system has been developed that for the first time allows the decarboxylative crosscoupling of aryl and acyl carboxylates with aryl triflates. In contrast to aryl halides, these electrophiles give rise to non-coordinating anions as byproducts, which do not interfere with the decarboxylation step that leads to the generation of the carbon nucleophilic crosscoupling partner. As a result, the scope of carboxylate substrates usable in this transformation was extended from ortho-substituted or otherwise activated derivatives to a broad range of ortho-, meta-, and para-substituted aromatic carboxylates. Two alternative protocols have been optimized, one involving heating the substrates in the presence of CuI/1,10- phenanthroline (10-15 mol %) and PdI2/phosphine (23 mol%) in NMP for 1-24 h, the other involving CuI/l,10-phenanthroline (615mol%) and PdBr2/Tol-BINAP (2 mol % ) in NMP using microwave heating for 5-10 min. While most products are accessible using standard heating, the use of microwave irradiation was found to be beneficial especially for the conversion of non-activated carboxylates with functionalized aryl triflates. The synthetic utility of the transformation is demonstrated with 48 examples showing the scope and limitations of both protocols. In mechanistic studies, the special role of microwave irradiation is elucidated, and further perspectives of decarboxylase crosscouplings are discussed.
Palladium acetate immobilized in a hierarchical MFI zeolite-supported ionic liquid: A highly active and recyclable catalyst for Suzuki reaction in water
Jin, Myung-Jong,Taher, Abu,Kang, Hee-Jae,Choi, Minkee,Ryoo, Ryong
experimental part, p. 309 - 313 (2010/04/22)
Palladium acetate was immobilized in thin ionic liquid layers on the mesopore wall of hierarchical MFI zeolite, and tested as a catalyst for Suzuki coupling reaction in water. The catalyst exhibited very high activity in the coupling of various aryl bromides with arylboronic acids. Moreover, the catalyst could be recycled without a significant loss of catalytic activity.
A recyclable triethylammonium ion-tagged diphenylphosphine palladium complex for the Suzuki-Miyaura reaction in ionic liquids
Lombardo, Marco,Chiarucci, Michel,Trombini, Claudio
experimental part, p. 574 - 579 (2010/04/23)
Suzuki-Miyaura reactions of aryl bromides and arylboronic acids proceed in good to excellent yields in a pyrrolidinium ionic liquid by using a preformed air stable and easily handled triethylammonium-tagged diphenylphosphine palladium(ii) complex (2). The reaction requires short reaction times and mild temperature conditions and does not show any tendency towards the formation of palladium black. After extraction of the product, the catalyst containing ionic liquid phase is easily recycled for 6 times, with no significant loss of catalytic activity.
Structurally simple inhibitors of lanosterol 14α-demethylase are efficacious in a rodent model of acute Chagas disease
Suryadevara, Praveen Kumar,Olepu, Srinivas,Lockman, Jeffrey W.,Ohkanda, Junko,Karimi, Mandana,Verlinde, Christophe L. M. J.,Kraus, James M.,Schoepe, Jan,Van Voorhis, Wesley C.,Hamilton, Andrew D.,Buckner, Frederick S.,Gelb, Michael H.
experimental part, p. 3703 - 3715 (2010/04/24)
We report structure-activity studies of a large number of dialkyl imidazoles as inhibitors of Trypanosoma cruzi lanosterol-14α-demethylase (L14DM). The compounds have a simple structure compared to posaconazole, another L14DM inhibitor that is an anti-Chagas drug candidate. Several compounds display potency for killing T. cruzi amastigotes in vitro with values of EC 50 in the 0.4-10 nM range. Two compounds were selected for efficacy studies in a mouse model of acute Chagas disease. At oral doses of 20-50 mg/kg given after establishment of parasite infection, the compounds reduced parasitemia in the blood to undetectable levels, and analysis of remaining parasites by PCR revealed a lack of parasites in the majority of animals. These dialkyl imidazoles are substantially less expensive to produce than posaconazole and are appropriate for further development toward an anti-Chagas disease clinical candidate.
Palladium-phosphinous acid-catalyzed cross-coupling of aryl and acyl halides with aryl-, alkyl-, and vinylzinc reagents
Xu, Hanhui,Ekoue-Kovi, Kekeli,Wolf, Christian
, p. 7638 - 7650 (2008/12/22)
(Chemical Equation Presented) Several palladium-phosphinous acids have been prepared and employed in cross-coupling reactions of aryl or acyl halides with aliphatic and aromatic organozinc reagents. The POPd7-catalyzed reaction of aryl halides, including electron-rich aryl chlorides, and arylzinc reagents was found to afford biaryls exhibiting alkoxy, alkylthio, amino, ketone, cyano, nitro, ester, and heteroaryl groups in 75-93% yield. Excellent results were obtained with sterically hindered substrates which gave di- and tri-ortho-substituted biaryls in up to 92% yield. Aryl halides also undergo POPd7-catalyzed aryl-vinyl and aryl-alkyl bond formation under mild conditions. Styrenes and alkylarenes were prepared in 79-93% yield from aryl halides and vinyl or alkylzinc reagents. The replacement of aryl halides by acyl halides provides access to ketones which were produced in up to 98% yield when POPd was used as catalyst. This approach overcomes the limited substrate scope, reduced regiocontrol, and low functional group tolerance of traditional Friedel-Crafts acylation methods.
Microwave-assisted Suzuki coupling reactions with an encapsulated palladium catalyst for batch and continuous-flow transformations
Baxendale, Ian R.,Griffiths-Jones, Charlotte M.,Ley, Steven V.,Tranmer, Geoffrey K.
, p. 4407 - 4416 (2008/02/07)
This article describes the design, optimisation and development of a Suzuki cross-coupling protocol mediated by an efficient palladium-en-capsulated catalyst (Pd EnCat) under microwave irradiation. The methodology has been used in both batch mode for classical library preparation and in continuous-flow applications furnishing multigram quantities of material. Described is a method that uses direct focused microwave heating whilst applying an external cooling source. This enables a lower than normal bulk temperature to be maintained throughout the reaction period leading to significant improvements in the overall yield and purity of the reaction products. Additional aspects of this novel heating protocol are discussed in relation to the prolonged lifetime and enhanced reactivity of the immobilised catalyst system.
Non-cross-linked polystyrene-supported triphenylphosphine-microencapsulated palladium: An efficient and recyclable catalyst for Suzuki-Miyaura reactions
He, Helen Song,Yan, Jessie Jing,Shen, Ruxiang,Zhuo, Shangjun,Toy, Patrick H.
, p. 563 - 566 (2007/10/03)
A recyclable, all-in-one, polystyrene-microencapsulated palladium catalyst has been developed and used as a heterogeneous catalyst in Suzuki-Miyaura coupling reactions. This catalyst can be recovered and reused with only minimal palladium leaching observed. Georg Thieme Verlag Stuttgart.
