18254-00-7Relevant academic research and scientific papers
Mizoroki–Heck Cross-Coupling of Acrylate Derivatives with Aryl Halides Catalyzed by Palladate Pre-Catalysts
Islam, Mohammad Shahidul,Nahra, Fady,Tzouras, Nikolaos V.,Barakat, Assem,Cazin, Catherine S. J,Nolan, Steven P.,Al-Majid, Abdullah Mohammed
supporting information, p. 4695 - 4699 (2019/11/13)
The Mizoroki–Heck (MH) reaction involving aryl halides with various acrylates and acrylamides has been studied using air and moisture-stable imidazolium-based palladate pre-catalysts. These pre-catalysts can be converted into Pd-NHC species (NHC = N-heterocyclic carbene) under catalytic conditions and are capable of facilitating the Mizoroki–Heck reaction of aryl halides with various acrylates. The effects of solvent, catalyst loading, temperature and bases on the reaction outcome have been investigated. Various coupling partners were tolerated under the optimal reaction conditions catalyzed by palladate 1, [SIPr·H][Pd(η3-2-Me-allyl)Cl2]. The efficiency of the optimized synthetic methodology was tested on various aryl halides and substituted acrylates as well as acrylamides. The MH reaction yielded the coupled products in good to excellent isolated yields (up to 98%).
Selective and facile synthesis of α,β-unsaturated nitriles and amides with N-hydroxyphthalimide as the nitrogen source
Yan, Yiyan,Xu, Xiaohe,Jie, Xiaokang,Cheng, Jingya,Bai, Renren,Shuai, Qi,Xie, Yuanyuan
supporting information, p. 2793 - 2796 (2018/06/25)
The direct conversion of α,β-unsaturated aldehydes to corresponding nitriles promoted by Pd(OAc)2 and phthalic acid which was hydrolyzed from N-hydroxyphthalimide (NHPI) has been disclosed. Additionally, it was found that when water was used as the solvent, α,β-unsaturated amides was obtained as the main products in good to excellent yields. It was first reported that NHPI was utilized as the nitrogen source to synthesize α,β-unsaturated nitriles and amides from aldehydes. Control experiment demonstrated that aldehydes undergo a process of oximation and dehydration to form nitriles and amides.
Copper(II)-Catalyzed Reactions of α-Keto Thioesters with Azides via C-C and C-S Bond Cleavages: Synthesis of N-Acylureas and Amides
Maity, Rajib,Naskar, Sandip,Das, Indrajit
, p. 2114 - 2124 (2018/02/23)
Cu(II)-catalyzed reaction of α-keto thioesters with trimethylsilyl azide (TMSN3) proceeds with the transformation of the thioester group into urea through C-C and C-S bond cleavages, constituting a practical and straightforward synthesis of N-acylureas. When diphenyl phosphoryl azide (DPPA) is used instead as the azide source in an aqueous environment, primary amides are formed via substitution of the thioester group. The reactions are proposed to proceed through Curtius rearrangement of the initially formed α-keto acyl azide to generate an acyl isocyanate intermediate, which reacts further with an additional amount of azide or water and rearranges to afford the corresponding products. To demonstrate the potentiality of the method, one-step syntheses of pivaloylurea and isovaleroylurea, displaying anticonvulsant activities, have been carried out.
Optimization and Evaluation of 5-Styryl-Oxathiazol-2-one Mycobacterium tuberculosis Proteasome Inhibitors as Potential Antitubercular Agents
Russo, Francesco,Gising, Johan,?kerbladh, Linda,Roos, Annette K.,Naworyta, Agata,Mowbray, Sherry L.,Sokolowski, Anders,Henderson, Ian,Alling, Torey,Bailey, Mai A.,Files, Megan,Parish, Tanya,Karlén, Anders,Larhed, Mats
, p. 342 - 362 (2015/06/30)
This is the first report of 5-styryl-oxathiazol-2-ones as inhibitors of the Mycobacterium tuberculosis (Mtb) proteasome. As part of the study, the structure-activity relationship of oxathiazolones as Mtb proteasome inhibitors has been investigated. Furthermore, the prepared compounds displayed a good selectivity profile for Mtb compared to the human proteasome. The 5-styryl-oxathiazol-2-one inhibitors identified showed little activity against replicating Mtb, but were rapidly bactericidal against nonreplicating bacteria. (E)-5-(4-Chlorostyryl)-1,3,4-oxathiazol-2-one) was most effective, reducing the colony-forming units (CFU)/mL below the detection limit in only seven days at all concentrations tested. The results suggest that this new class of Mtb proteasome inhibitors has the potential to be further developed into novel antitubercular agents for synergistic combination therapies with existing drugs.
Heck arylation of conjugated alkenes with aryl bromides or chlorides catalyzed by immobilization of palladium in MCM-41
Yao, Fang,Liu, Jiaqin,Cai, Mingzhong
, p. 681 - 686 (2013/07/26)
A new 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-PdCl2] was conveniently synthesized from commercially available and cheap 3-(2-aminoethylamino) propyltrimethoxysilane via immobilization on MCM-41, followed by reacting with palladium chloride. It was found that this heterogeneous palladium complex is a highly efficient catalyst for Heck arylation of conjugated alkenes with aryl bromides or chlorides using tetrabutylammonium bromide as additive and can be reused for at least six consecutive trials without any decreases in activity.
The acid-mediated ring opening reactions of α-aryl-lactams
King, Frank D.,Caddick, Stephen
supporting information; experimental part, p. 3244 - 3252 (2012/06/01)
4-Aryl-azetidin-2-ones (β-lactams) undergo ring opening with triflic acid to give cinnamamides which, in benzene, react further to give 3-aryl-3-phenyl-propionamides. Prolonged reaction times in benzene give 3,3-diphenyl-propionamide via an aryl/phenyl ex
Solid supported palladium(0) nano/microparticle: A ligand-free efficient recyclable heterogeneous catalyst for mono- and β,β-double-Heck reaction
Sharma, Dharminder,Kumar, Sandeep,Shil, Arun K.,Guha, Nitul Ranjan,Bandna,Das, Pralay
supporting information, p. 7044 - 7051 (2013/01/15)
Solid supported palladium nano/microparticles were found to be active catalysts to perform mono- and β,β-double-Heck reactions. Different β-unsubstituted and substituted alkenes including acrylate, methacrylate, crotonate, styrene, acrylonitrile, and acrylamide were investigated successfully for mono- and β,β-double-Heck reactions with aryl iodide under milder reaction condition. One-pot β,β-double-Heck reaction of aryl iodides with α,β-unsaturated ester, amide, nitrile, and styrene derivatives were also performed under standard reaction conditions. Wide functional group tolerance, easy catalyst recovery, and recyclability up to twelve times without significant loss of catalytic activity added extra importance to the present process.
The acid-mediated ring opening/cyclisation reaction of N-benzyl-α- aryl-azetidinones
King, Frank D.,Caddick, Stephen
, p. 9350 - 9354 (2012/11/07)
N-Benzyl-4-aryl-azetidinones undergo ring opening with triflic acid to form N-benzyl-cinnamamides, which either undergo cyclisation to give 5-aryl-benzazepin-3-ones or N-debenzylation to give cinnamamides.
Binaphthyl-bridged bis-imidazolinium salts as N-heterocyclic carbene ligand precursors in the palladium-catalyzed Heck reaction
Wu, Hui,Jin, Can,Huang, Guoli,Wang, Lianjun,Jiang, Juli,Wang, Leyong
experimental part, p. 951 - 956 (2012/02/05)
Two new bis-imidazolinium salts (4a, 4b) have been synthesized as precursors of N-heterocyclic carbenes (NHCs) from the commercially available (R)-2,2′-dihydroxy-1,1′-binaphthalene. The two bis-imidazolinium salts were used as efficient precursor of NHC ancillary ligands in the palladium-catalyzed Heck reaction. Good to excellent yields and high stereoselectivities were obtained with ethyl acrylate, acrylonitrile, and acrylamide as starting materials. The structure of bis-imidazolinium salt 4b was further characterized by single crystal X-ray diffraction analysis. Science China Press and Springer-Verlag Berlin Heidelberg 2011.
