24393-56-4Relevant articles and documents
Tuning and enhancement of the Mizoroki-Heck reaction using polarized Pd nanocomposite carbon aerogels
Martín, Laura,Molins, Elies,Vallribera, Adelina
, p. 10208 - 10212 (2016)
The application of a positive electric field on a Pd(0)-carbon aerogel nanocomposite enhances the reaction rate of the Mizoroki-Heck reaction. By contrast, when a negative potential is employed the reaction is inhibited. On the other hand, chronoamperometry measurements have revealed the polarizing current intensity as an indirect measure of the reaction evolution. The cationic nature of the reaction intermediates was unambiguously confirmed and a polar mechanism has been finally proposed.
A microreactor for microwave-assisted capillary (continuous flow) organic synthesis
Comer, Eamon,Organ, Michael G.
, p. 8160 - 8167 (2005)
A capillary-based flow system has been developed for conducting microscale organic synthesis with the aid of microwave irradiation. The capillary internal diameter investigated ranged from 200 to 1200 μm, while the flow rate was varied between 2 and 40 μL/min, which corresponds to the sample being irradiated approximately 4 min. Other parameters investigated include reaction concentration and power setting of the microwave. Excellent conversion was observed in a variety of cross coupling and ring-closing metathesis (RCM) reactions employing metal catalysts and in nucleophilic aromatic substitution and Wittig reactions that do not employ metals. Reactions that have solids in them do not seem to pose a significant concern for the method, such as blocked channels. It was shown that capillaries coated internally with thin films of Pd metal show tremendous rate accelerations and that the thin films themselves are capable of catalyzing Suzuki-Miyaura reactions with no exogenous catalyst added. Importantly, it has been demonstrated that reagents in separate syringes can be coinjected into the capillary, mix, and react with none of the laminar flow problems that plague microreactor (lab on a chip) technology. This paves the way to use microwave-assisted, flow capillary synthesis as a powerful and efficient means to replace "one-at-a-time" microwave synthesis to provide libraries of compounds in a scale suitable for biological screening purposes.
Barium Hydroxide as Catalyst in Organic Reactions; V. Application in the Horner Reaction under Solid-Liquid Phase-Transfer Conditions
Sinisterra, J. V.,Mouloungui, Z.,Delmas, M.,Gaset, A.
, p. 1097 - 1100 (1985)
A new application of a barium hydroxide catalyst for the Horner reaction is described.The scope of the synthetic method is shown; furthermore, the yields are higher and the reaction times shorter than those previously reported for similar experimental conditions (solid-liquid).Ethyl 3-(1'-pyrenyl)-acrylate and the 3-(1'-pyrenyl)-acrylonitrile are described for the first time.
Photoinduced Regioselective Olefination of Arenes at Proximal and Distal Sites
Ali, Wajid,Anjana, S. S.,Bhattacharya, Trisha,Chandrashekar, Hediyala B.,Goswami, Nupur,Guin, Srimanta,Maiti, Debabrata,Panda, Sanjib,Prakash, Gaurav,Saha, Argha,Sasmal, Sheuli,Sinha, Soumya Kumar
supporting information, p. 1929 - 1940 (2022/02/01)
The Fujiwara-Moritani reaction has had a profound contribution in the emergence of contemporary C-H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had
Pd/Cu-Free Cobalt-Catalyzed Suzuki and Heck Using Green Bio-Magnetic Hybrid and DFT-Based Theoretical Study
Hajipour, Abdol R.,Khorsandi, Zahra,Ahmadi, Mehnoosh,Jouypazadeh, Hamidreza,Mohammadi, Bahareh,Farrokhpour, Hossein
, p. 2842 - 2850 (2021/02/01)
Abstract: Several highly efficient and magnetically recyclable cobalt catalytic systems were prepared using magnetic chitosan and some safe and available organic compounds (Co-ligand@MNPs/Ch). The structure of these nanocomposites was confirmed by various physicochemical techniques such as FT-IR, XRD, TGA, VSM, TEM, SEM, CHNS and ICP-OES. These nano composites exhibit remarkable catalytic efficiency for Suzuki and Heck cross-coupling reactions in mild and green reaction conditions. The facile accessibility of starting materials, possible performance in air and eco-friendly conditions are merits of our catalysts. In addition, to describe and go insight to role and effect of ligands present in these catalysts, electrostatic interactions, density functional theory (DFT) model in molecular method were employed. Graphic Abstract: [Figure not available: see fulltext.]
The Mizoroki-Heck reaction in mesoionic 1-butyl-3-methyltetrazolium-5-olate
Araki, Shuki,Hirashita, Tsunehisa,Kurabayashi, Hideaki
, (2021/10/12)
1-Butyl-3-methyltetrazolium-5-olate (1), a mesoionic compound, exists as a liquid at room temperature and can be used as a polar solvent for the Mizoroki-Heck reaction, wherein it has been proven to be a superior solvent to other solvents. The reaction of iodobenzene with ethyl acrylate in the presence of palladium acetate in mesoionic liquid 1 at 40 °C for 24 h gave ethyl cinnamate in 78% yield in the absence of ligands, while the use of other solvents, such as [bmim][BF4], [bmim][PF6], and DMF gave lower yields (43%, 37%, and 17%, respectively) under the same conditions. Heck-type coupling reactions of electron-deficient or electron-rich aryl iodides and bromobenzenes with olefins (15 examples, 7%–97%) were performed in 1. When a phosphine ligand was added to the reaction mixture, aryl bromides could be used, and the mesoionic liquid containing the catalysts could be reused at least five times.
Asymmetric synthesis of piperidines using the nitro-Mannich reaction☆
Anderson, James C.,Bouvier-Israel, Eva,Rundell, Christopher D.,Zhang, Xiangyu
, (2020/12/21)
A method for the synthesis of functionalized piperidines containing 3 contiguous stereocentres in the 2-,3- and 4- positions uses a diastereoselective nitro-Mannich to control stereochemistry. The nitro-Mannich reaction between a β-aryl/heteroaryl substituted nitroalkanes and glyoxylate imine provides β-nitro-amines with good selectivity (70:30 to >95:5) for the syn, anti-diastereoisomers. Reductive cyclisation with BF3.OEt2 and Et3SiH gave, after purification, stereochemically pure piperidines in 19–57% yield for ten examples with different 4-aryl/heteroaryl substituents.
Intramolecular Sakurai Allylation of Geminal Bis(silyl) Enamide with Indolenine. A Diastereoselective Cyclization to Form Functionalized Hexahydropyrido[3,4- b]Indole
Chen, Yi,Gao, Lu,Song, Xuanyi,Song, Zhenlei
supporting information, p. 124 - 128 (2021/01/13)
A fluoride-promoted intramolecular Sakurai allylation of geminal bis(silyl) enamide with indolenine has been developed. The reaction facilitates an efficient cyclization to give hexahydropyrido[3,4-b]indoles in good yields with high diastereoselectivity. The resulted cis, trans-stereochemistry further enables the ring-closing metathesis (RCM) reaction of two alkene moieties, giving a tetracyclic N-hetereocycle widely found as the core structure in akuammiline alkaloids.
Photoinduced Oxidative Alkoxycarbonylation of Alkenes with Alkyl Formates
Tang, Wan-Ying,Chen, Ling,Zheng, Ming,Zhan, Le-Wu,Hou, Jing,Li, Bin-Dong
supporting information, p. 3939 - 3943 (2021/05/26)
A photoinduced oxidative alkoxycarbonylation of alkenes initiated by intermolecular addition of alkoxycarbonyl radicals has been demonstrated. Employing alkyl formates as alkoxycarbonyl radical sources, a range of α,β-unsaturated esters were obtained with good regioselectivity and E selectivity under ambient conditions.
Palladium Nanoparticles Anchored on Magnesium Organosilicate: An Effective and Selective Catalyst for the Heck Reaction
Dos Santos, Beatriz F.,Da Silva, Beatriz A. L.,De Oliveira, Aline R.,Sarragiotto, Maria H.,Rinaldi, Andrelson W.,Domingues, Nelson Luís C.
supporting information, p. 1301 - 1306 (2020/11/04)
A new and effective palladium catalyst supported on a magnesium organosilicate for application in the Heck reaction is presented. A group of compounds comprising 22 examples were synthesized in moderate to high yields (up to 99%) within a short time. The palladium supported on magnesium organosilicate catalyst was characterized as an amorphous solid by SEM, containing around 33% of palladium inside the solid, and even with this low quantity of palladium, the catalyst was very efficient in the Heck reaction. Besides, based on the Scherrer equation, the crystallite size of the synthesized palladium nanoparticles was ultrasmall (around 1.3 nm). This strategy is a simple and efficient route for the formation of C-C bonds via the Heck cross-coupling reaction.
