27951-92-4Relevant academic research and scientific papers
Water-Sculpting of a Heterogeneous Nanoparticle Precatalyst for Mizoroki-Heck Couplings under Aqueous Micellar Catalysis Conditions
Pang, Haobo,Hu, Yuting,Yu, Julie,Gallou, Fabrice,Lipshutz, Bruce H.
supporting information, p. 3373 - 3382 (2021/04/07)
Powdery, spherical nanoparticles (NPs) containing ppm levels of palladium ligated by t-Bu3P, derived from FeCl3, upon simple exposure to water undergo a remarkable alteration in their morphology leading to nanorods that catalyze Mizoroki-Heck (MH) couplings. Such NP alteration is general, shown to occur with three unrelated phosphine ligand-containing NPs. Each catalyst has been studied using X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and cryogenic transmission electron microscopy (cryo-TEM) analyses. Couplings that rely specifically on NPs containing t-Bu3P-ligated Pd occur under aqueous micellar catalysis conditions between room temperature and 45 °C, and show broad substrate scope. Other key features associated with this new technology include low residual Pd in the product, recycling of the aqueous reaction medium, and an associated low E Factor. Synthesis of the precursor to galipinine, a member of the Hancock family of alkaloids, is suggestive of potential industrial applications.
Metal-Free Synthesis of Alkenylazaarenes and 2-Aminoquinolines through Base-Mediated Aerobic Oxidative Dehydrogenation of Benzyl Alcohols
Batra, Sanjay,Dahatonde, Dipak J.,Ghosh, Aritra
, p. 2746 - 2751 (2021/06/25)
A metal-free, base-mediated, and atom-efficient oxidative dehydrogenative coupling of substituted phenylmethanols (benzyl alcohols) with methyl azaarenes or phenylacetonitriles to afford substituted alkenylazaarenes or 2-aminoquinolines, respectively is described. CsOH.H2O was discovered to be the base of choice for obtaining optimal yields of the title compounds, although the reaction could proceed with KOH as well. The protocol that works efficiently in the presence of air is amenable over broad range of substrates.
Copper-catalyzed asymmetric silyl addition to alkenyl-substituted N -heteroarenes
Zeng, Ya-Li,Chen, Bo,Wang, Ya-Ting,He, Cheng-Yu,Mu, Zi-Yuan,Du, Ji-Yuan,He, Long,Chu, Wen-Dao,Liu, Quan-Zhong
supporting information, p. 1693 - 1696 (2020/02/20)
Asymmetric conjugate addition of PhMe2SiBPin to a wide range of N-heteroaryl alkenes proceeded in the presence of a copper catalyst coordinated with an easily accessible chiral phosphoramidite ligand to afford useful β-silyl N-heteroarenes in high yields (up to 96%) and excellent enantioselectivities (up to 97% ee).
Continuous Flow Synthesis of Quinolines via a Scalable Tandem Photoisomerization-Cyclization Process
Di Filippo, Mara,Baumann, Marcus
, p. 6199 - 6211 (2020/08/26)
A continuous photochemical process is presented that renders a series of quinoline products via an alkene isomerization and cyclocondensation cascade. It is demonstrated that a high-power LED lamp generates the desired targets with higher productivity and efficiency than a medium-pressure Hg-lamp. The scope of this tandem process is established and allows for the generation of various substituted quinolines in high yields and with throughputs of greater than one gram per hour. Finally, this effective flow process is coupled with a telescoped hydrogenation reaction to render a series of tetrahydroquinolines including the antimalarial natural product galipinine.
NaCl as Catalyst and Water as Solvent: Highly E-Selective Olefination of Methyl Substituted N-Heteroarenes with Benzyl Amines and Alcohols
Hazra, Susanta,Tiwari, Vikas,Verma, Ashutosh,Dolui, Pritam,Elias, Anil J.
supporting information, p. 5496 - 5501 (2020/07/14)
Oxidative coupling of benzylamines and alcohols with methyl substituted N-heteroarenes such as quinolines and quinoxalines has been achieved using chloride, a sea abundant anion as the catalyst for practical synthesis of a wide range of E-disubstituted olefins in aqueous medium. Detailed mechanistic studies and control experiments were carried out to deduce the reaction mechanism which indicated that in situ formed ClO2- is the active form of the catalyst. We have successfully carried out a 1 g scale reaction using this methodology, and five pharmaceutically relevant conjugated olefins were also synthesized by this method in moderate to good yields.
Preparation method of trans-disubstituted olefin
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Paragraph 0046-0053, (2020/02/27)
The invention relates to the technical field of organic chemical synthesis, and in particular, relates to a preparation method of trans-disubstituted olefin. According to the preparation method, primary alcohol and methyl azacycle are taken as raw materials, transition metal salt, nitric oxide and alkali are taken as catalysts, an organic solution is taken as a reaction medium, and reaction is carried out in an oxygen atmosphere. According to the preparation method, a reaction by-product is only water, the environment is not polluted, the required transition metal catalyst is cheap and easy toobtain, the reaction does not need high temperature, and the reaction cost and the requirements on reaction conditions can be reduced.
Nickel-catalysed direct α-olefination of alkyl substituted N-heteroarenes with alcohols
Das, Jagadish,Vellakkaran, Mari,Banerjee, Debasis
supporting information, p. 7530 - 7533 (2019/07/04)
Catalytic α-olefination of alkylheteroarenes with primary alcohols via dehydrogenative coupling is presented. A simple nickel catalyst system stabilised by readily available nitrogen ligands enables a series of interesting E-configured vinylarenes (confirmed by X-ray crystal-structure analysis) to be synthesised in good to excellent yields with olefin/alkane selectivity of >20:1. Hydrogen and water are generated as byproducts and quantitative determination of H2 was performed.
Iron-Catalyzed Coupling of Methyl N-Heteroarenes with Primary Alcohols: Direct Access to E-Selective Olefins
Das, Jagadish,Vellakkaran, Mari,Sk, Motahar,Banerjee, Debasis
supporting information, p. 7514 - 7518 (2019/10/02)
An efficient Fe-catalyzed system is reported for direct α-olefination of methyl-substituted N-heteroarenes with primary alcohols. The catalytic dehydrogenative coupling enables a series of functionalized E-olefinated N-heteroaromatics with excellent selectivity (>99%). Initial mechanistic studies including deuterium-labeling experiments provide evidence for the participation of the benzylic C-H/D bond of alcohols.
Manganese-Catalyzed Direct Olefination of Methyl-Substituted Heteroarenes with Primary Alcohols
Barman, Milan K.,Waiba, Satyadeep,Maji, Biplab
supporting information, p. 9126 - 9130 (2018/07/25)
Herein, we present the first catalytic direct olefination of methyl-substituted heteroarenes with primary alcohols through an acceptorless dehydrogenative coupling. The reaction is catalyzed by a complex of the earth-abundant transition metal manganese that is stabilized by a bench-stable NNN pincer ligand derived from 2-hydrazinylpyridine. The reaction is environmentally benign, producing only hydrogen and water as byproducts. A large number of E-disubstituted olefins were selectively obtained with high efficiency.
A concise and efficient synthesis of tetrahydroquinoline alkaloids using the phase transfer mediated Wittig olefination reaction
Diaz-Mu?oz, Gaspar,Isidorio, Raquel Geralda,Miranda, Izabel Luzia,de Souza Dias, Gabriel Nunes,Diaz, Marisa Alves Nogueira
, p. 3311 - 3315 (2017/07/27)
The present study describes the total synthesis of 1,2,3,4-tetrahydroquinoline alkaloids (±)-galipinine, (±)-cuspareine, (±)-galipeine and (±)-angustureine, in three steps and high yields (78%, 76%, 74%, and 66%, respectively) from common aldehyde and the ylide respectives. The key step of this approach is based on an unusual Wittig reaction by using the phase transfer medium (aq. NaOH/CH2Cl2 1:1 or t-BuOK/t-BuOH/CH2Cl2 1:1), affording olefinic intermediates in high yields.
