61064-99-1Relevant academic research and scientific papers
Stereocontrolled synthesis of (E)-stilbene derivatives by palladium-catalyzed Suzuki-Miyaura cross-coupling reaction
Rau, Hailee H.,Werner, Nathan S.
, p. 2693 - 2696 (2018/04/30)
A general procedure for the stereocontrolled synthesis of (E)-stilbene derivatives by palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of (E)-2-phenylethenylboronic acid pinacol ester with aryl bromides was investigated. (E)-2-Phenylethenylboronic acid pinacol ester was prepared by 9-BBN-catalyzed hydroboration of phenylacetylene with pinacolborane. This reagent undergoes facile palladium-catalyzed cross-coupling with a diverse set of aryl bromides to provide the corresponding (E)-stilbene derivatives in moderate to good yield. The use of the sterically bulky t-Bu3PHBF4 ligand was crucial to the successful coupling of electron-rich and electron-poor aryl bromides. Complete stereochemical retention of the (E)-2-phenylethenylboronic acid pinacol ester alkene geometry was observed in all of the (E)-stilbene derivatives synthesized.
An efficient Pd-NHC catalyst system in situ generated from Na2PdCl4 and PEG-functionalized imidazolium salts for Mizoroki-Heck reactions in water
Sun, Nan,Chen, Meng,Jin, Liqun,Zhao, Wei,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
supporting information, p. 1735 - 1744 (2017/09/27)
Three PEG-functionalized imidazolium salts L1-L3 were designed and prepared from commercially available materials via a simple method. Their corresponding water soluble Pd-NHC catalysts, in situ generated from the imidazolium salts L1-L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki-Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium salt L1, bearing a pyridine-2-methyl substituent at the N3 atom of the imidazole ring, showed the best catalytic activity. Under the optimal conditions, a wide range of substituted alkenes were achieved in good to excellent yields from various aryl bromides and alkenes with the catalyst TON of up to 10,000.
An effective Pd nanocatalyst in aqueous media: Stilbene synthesis by Mizoroki-Heck coupling reaction under microwave irradiation
García, Carolina S.,Uberman, Paula M.,Martín, Sandra E.
, p. 1717 - 1727 (2017/09/27)
Aqueous Mizoroki-Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The reaction was carried out in a short reaction time and with low catalyst loading, leading to high turnover frequency (TOFs of the order of 100 h-1). The advantages like operational simplicity, high robustness, efficiency and turnover frequency, the utilization of aqueous media and simple product work-up make this protocol a great option for stilbene syntheses by Mizoroki-Heck reaction.
Gas-phase domino cyclization of phosphonium ylides leading to the total synthesis of Eustifoline D
Aitken, R. Alan,Murray, Lorna
supporting information, p. 4328 - 4332 (2017/10/17)
Six stabilised phosphonium ylides bearing ortho-benzylaminophenyl and cinnamoyl (or a heterocyclic analogue) groups have been prepared and upon flash vacuum pyrolysis at 800 °C were found to undergo cascade cyclization processes to give mainly 3-styrylquinolines but also in some cases ring-fused carbazoles and other fused-ring heterocyclic products. By starting with an appropriate ring-methylated precursor the natural product Eustifoline D was obtained in 19% yield in the pyrolysis in addition to the 3-(2-furylethenyl)quinoline (46%).
D -glucosamine as a green ligand for palladium-catalyzed cross-coupling of aryl and heteroaryl halides
Jha, Abadh Kishor,Shahni, Rahul Kumar,Jain, Nidhi
supporting information, p. 259 - 264 (2015/03/05)
Naturally occurring d-glucosamine works as an efficient green alternative to phosphines in palladium-catalyzed Heck coupling of aryl and heteroaryl halides. An array of trans-stilbene derivatives, aryl naphthyl alkenes, heteroaryl olefins, and β-aryl-substituted acrylates has been synthesized in short reaction times in moderate to high yields.
Bulky monodentate biphenylarsine ligands: Synthesis and evaluation of their structure effects in the palladium-catalyzed Heck reaction
Quinteros, Gisela J.,Uberman, Paula M.,Martín, Sandra E.
supporting information, p. 2698 - 2705 (2015/04/27)
Biphenyl-based arsine ligands were prepared in two-step fashion by Pd-catalyzed arsination and microwave-assisted Suzuki-Miyaura coupling, providing sterically demanding arsine ligands in overall isolated yields up to 82 % as air-stable solids. Short reaction times were achieved with the assistance of microwave irradiation in the direct and simple described protocol for the synthesis of biarylarsine ligands. The activities of the biphenyl arsine ligands were explored in Pd-catalyzed Heck coupling. As a general trend, the ligands with "blocked" ortho-positions on the non-arsine-containing ring of the biphenyl backbone performed more efficiently in the coupling reaction. This catalytic system allowed several interesting stilbenes to be obtained in very good yields. Sterically demanding biphenyl-based arsine ligands were prepared in high overall yields by microwave-assisted Suzuki-Miyaura coupling. The ligands were evaluated in the Pd-catalyzed Heck coupling reaction; the most active were those with "blocked" ortho-positions on the non-arsine-containing ring of the biphenyl backbone.
Heck, Sonogashira, and Hiyama reactions catalyzed by palladium nanoparticles stabilized by tris-imidazolium salt
Planellas, Marc,Moglie, Yanina,Alonso, Francisco,Yus, Miguel,Pleixats, Roser,Shafir, Alexandr
, p. 3001 - 3008 (2014/05/20)
Palladium nanoparticles, prepared by the hydrogenation of Pd(dba) 2 in the presence of a tris-imidazolium iodide as stabilizer, act as an efficient catalyst for Heck and copper-free Sonogashira reactions with a range of aryl iodides and bromides at 0.2 mol-% Pd loading. Moreover, we describe a convenient protocol for the fluoride-free Hiyama coupling of vinylsilanes with aryl iodides that involves the use of sodium hydroxide as promoter in a methanol/water mixture. Under the developed conditions, one-pot, double Heck and Hiyama-Heck reactions are successfully achieved.
Mizoroki-Heck reactions catalyzed by palladium dichloro-bis(aminophosphine) complexes under mild reaction conditions. the importance of ligand composition on the catalytic activity
Oberholzer, Miriam,Frech, Christian M.
supporting information, p. 1678 - 1686 (2013/10/01)
Dichloro-bis(aminophosphine) complexes of palladium with the general formula [(P{(NC5H10)3-n(C6H 11)n})2Pd(Cl)2] (where n = 0-2) are easily accessible, cheap and air stable, highly active and universally applicable C-C cross-coupling catalysts, which exhibit an excellent functional group tolerance. The ligand composition of amine-substituted phosphines (controlled by the number of P-N bonds) was found to effectively determine their catalytic activity in the Heck reaction, for which nanoparticles were demonstrated to be their catalytically active form. While dichloro{bis[1, 1′,1′′-(phosphinetriyl)tripiperidine]}palladium (1), the least stable complex (towards protons) within the series of [(P{(NC5H 10)3-n(C6H11)n}) 2Pd(Cl)2] (where n = 0-3), is a highly active Heck catalyst at 100 °C and, hence, a rare example of an effective and versatile Heck catalyst that efficiently operates under mild reaction conditions (100 °C or below), a significant successive drop in activity was noticed for dichloro-bis(1,1′-(cyclohexylphosphinediyl)dipiperidine)palladium (2, with n = 1), dichloro-bis(1-(dicyclohexylphosphinyl)piperidine)palladium (3, with n = 2) and dichloro-bis(tricyclohexylphosphine)palladium (4, with n = 3), of which the latter is essentially inactive (at least under the reaction conditions applied). This trend was explained by the successively increasing complex stability and its ensuing retarding effect on the (water-induced) generation of palladium nanoparticles thereof. This interpretation was experimentally confirmed (initial reductions of 1-4 into palladium(0) complexes of the type [Pd(P{(NC5H10)3-n(C6H 11)n})2] (where n = 0-3) were excluded to be the reason for the activity difference observed as well as molecular (Pd 0/PdII) mechanisms were excluded to be operative) and thus demonstrates that the catalytic activity of dichloro-bis(aminophosphine) complexes of palladium can-in reactions where nanoparticles are involved-effectively be controlled by the number of P-N bonds in the ligand system.
Microwave-assisted C-C cross-coupling reactions of aryl and heteroaryl halides in water
Dawood, Kamal M.,El-Deftar, Moteaa M.
experimental part, p. 319 - 330 (2010/10/03)
The catalytic activity of a benzimidazole-oxime Pd(II)-complex towards Suzuki and Heck C-C cross-coupling reactions of activated and deactivated aryl- and heteroaryl bromides under microwave irradiation as well as thermal heating using water as a green solvent was evaluated. The turnover frequency reached 420,000 under microwave condition ARKAT USA, Inc.
Heck reaction with heteroaryl halides in the presence of a palladium-tetraphosphine catalyst
Berthiol, Florian,Feuerstein, Marie,Doucet, Henri,Santelli, Maurice
, p. 5625 - 5628 (2007/10/03)
cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/1/2[PdCl (C3H5)]2 system catalyses efficiently the Heck reaction of heteroaryl halides with n-butyl acrylate, styrene, vinylpyridine and vinyl ether derivatives. High turnover numbers can be obtained for the reactions with halo pyridines, quinolines, furans or thiophenes.
