78347-97-4Relevant academic research and scientific papers
Palladium Loaded Dendronized Polymer as Efficient Polymeric Sustainable Catalyst for Heck Coupling Reaction
Hiba, K.,Krishna, G. Anjali,Prathapan, S.,Sreekumar, K.
, (2021/08/18)
The palladium incorporated amine-functionalized dendronized polymer was synthesized by the addition of palladium acetate to dendronized polymer in methanol at room temperature. Palladium species are immobilized onto the dendritic structure by their coordination with amino functional groups. The newly developed dendritic system showed high palladium content in the low generation level itself, which was found to be 4.19?mmol/g. This was fairly higher than, the other palladium-based catalysts. Energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, UV–Visible spectroscopy, and X-ray photoelectron spectroscopy were used to confirm the successful synthesis of the new catalyst. It was used as a homogeneous palladium catalyst for Heck coupling reaction between olefins and differently substituted aryl halides and the products were isolated in high yield. The products isolated were in trans configuration, which indicated the selectivity of the newly developed catalytic system. Also, this catalyst system was reused up to nine times without a significant decrease in its catalytic activity. The easy accessibility of catalytic sites, stability, resistance to metal leaching, high catalytic activity and remarkable stereoselectivity with a low amount of catalyst are all due to the dendritic support. The docking study was carried out for all the stilbene derivatives obtained by the Heck coupling reaction against DprE1 protein to study its potential antitubercular activity. All the compounds displayed superior docking score values over the range ??6.5 to ??8.2?kcal/mol, compared to the standard drug isoniazid with docking score of ??6.1?kcal/mol against DprE1. Graphic Abstract: [Figure not available: see fulltext.]
Wittig Olefination Using Phosphonium Ion-Pair Reagents Incorporating an Endogenous Base
Vetter, Anna C.,Gilheany, Declan G.,Nikitin, Kirill
, p. 1457 - 1462 (2021/03/08)
Despite common perception, the use of strong bases in Wittig chemistry is utterly unnecessary: we report a series of novel ion-pair phosphonium carboxylate reagents which are essentially "storable ylides". These reagents are straightforwardly prepared in excellent yields, and their fluxional nature permits clean olefination of a broad range of aldehydes and even hemiacetals.
New 1,2,3-triazole based bis- And trisphosphine ligands: Synthesis, transition metal chemistry and catalytic studies
Balakrishna, Maravanji S.,Butcher, Ray J.,Kunchur, Harish S.,Namdeo, Pavan K.,Radhakrishna, Latchupatula
, p. 3434 - 3449 (2020/03/27)
The syntheses and transition metal chemistry of triazole-based bis- and tris-phosphines, 5-(diphenylphosphanyl)-1-(2-(diphenylphosphanyl)phenyl)-4-phenyl-1H-1,2,3-triazole (2), 5-(diphenylphosphanyl)-4-(2-(diphenylphosphanyl)phenyl)-1-phenyl-1H-1,2,3-tria
Syntheses of diarylethenes by perylene-catalyzed photodesulfonylation from ethenyl sulfones
Adachi, Kazumasa,Dakegata, Aki,Fukuyama, Takahide,Okuda, Yasuhiro,Orita, Akihiro,Ryu, Ilhyong,Takemoto, Mai,Wakamatsu, Kan,Watanabe, Hikaru
supporting information, p. 409 - 412 (2020/04/27)
Diarylethenes were obtained from the corresponding ethenyl sulfones by photocatalyzed desulfonylation using UV or blue LEDs. When perylene and i-Pr2NEt were used as a photocatalyst and a sacrificing reagent, respectively, this desulfonylation proceeded smoothly to afford the desired ethenes with the functional groups such as chloro, alkoxy and heteroaromatic rings remaining untouched. The use of a flow photoreactor enabled this desulfonylation to proceed more rapidly to finish in an hour of residence time.
Ruthenium-Catalyzed E-Selective Alkyne Semihydrogenation with Alcohols as Hydrogen Donors
Ekebergh, Andreas,Begon, Romain,Kann, Nina
, p. 2966 - 2975 (2020/03/04)
Selective direct ruthenium-catalyzed semihydrogenation of diaryl alkynes to the corresponding E-alkenes has been achieved using alcohols as the hydrogen source. The method employs a simple ruthenium catalyst, does not require external ligands, and affords the desired products in > 99% NMR yield in most cases (up to 93% isolated yield). Best results were obtained using benzyl alcohol as the hydrogen donor, although biorenewable alcohols such as furfuryl alcohol could also be applied. In addition, tandem semihydrogenation-alkylation reactions were demonstrated, with potential applications in the synthesis of resveratrol derivatives.
Method for synthesizing trans-olefin compound
-
Paragraph 0095-0098, (2020/06/20)
The invention discloses a trans-olefin compound synthesis method, which comprises: carrying out a heating reaction on an alkyne compound represented by a general formula (I), a reducing agent and a solvent to obtain a trans-olefin compound represented by a general formula (II), wherein the synthesis route is as follows: R1 and R2 are independently selected from hydrogen, alkyl, cycloalkyl or aryl;wherein the reducing agent is a sulfur-containing compound and is selected from at least one of thioacetamide, N,N-dimethyl dithiocarbamate dimethyl ammonium salt, dimethyl amino sodium dithioformatedihydrate, potassium ethyl xanthate and potassium isopropyl xanthate. According to the method, a cheap, efficient and safe reducing agent is utilized to realize high-selectivity reduction of alkyne to prepare trans-olefin under the condition of no transition metal catalysis, so that the method is simple and easy to implement, wide in substrate application range and easy to realize industrialization.
Xanthate-mediated synthesis of (E)-alkenes by semi-hydrogenation of alkynes using water as the hydrogen donor
Luo, Xianglin,Chen, Xiuwen,Chen, Lu,Zhang, Kun,Li, Yibiao
supporting information, p. 2170 - 2173 (2019/02/24)
Semi-hydrogenation of alkynes is one of the most widely used methods for obtaining alkenes in laboratory preparation and in industry. Transition metal catalysts have been extensively studied for this transformation, but the tolerance of functional groups, such as pyridine,-OH,-NH2,-Bpin, and halides, and the toxicity of the trace amount of transition metal catalysts are still highly challenging. In this study, we report a general and robust strategy to achieve the semi-hydrogenation of alkynes using inexpensive and commercially available xanthate as the mediator. Mechanism studies support a non-radical process and H2O acts as the hydrogen donor.
Catalytic Chemoselective and Stereoselective Semihydrogenation of Alkynes to E-Alkenes Using the Combination of Pd Catalyst and ZnI2
Maazaoui, Radhouan,Abderrahim, Raoudha,Chemla, Fabrice,Ferreira, Franck,Perez-Luna, Alejandro,Jackowski, Olivier
supporting information, p. 7544 - 7549 (2019/01/03)
An efficient E-selective semihydrogenation of internal alkynes was developed under low dihydrogen pressure and low reaction temperature from commercially available reagents: Cl2Pd(PPh3)2, Zn0, and ZnI2. Kinetic studies and control experiments underline the significant role of ZnI2 in this process under H2 atmosphere, establishing that the transformation involves syn-hydrogenation followed by isomerization. This simple and easy-to-handle system provides a route to E-alkenes under mild conditions.
Synthesis of 1,2-diarylethylenes by Pd-catalyzed one-pot reaction of benzyl halides, tosylhydrazide, and aryl aldehydes
Shen, Xu,Liu, Ping,Liu, Yan,Dai, Bin
, p. 709 - 715 (2018/07/14)
Background: Substituted olefins are versatile functional groups and intermediates in chemistry, medicine, electronics, and optics and materials science fields because of their unique properties. One important class of substituted olefins 1,2-diarylethylenes have attracted considerable attention due to their presence in both natural products and pharmacologically active substances. Methods: In this paper, we developed a one-pot two-step coupling reaction of aryl aldehydes, tosylhydrazide with benzyl halides by using inexpensive Pd(PPh3)4 as catalyst, leading to a variety of 1,2- diphenylethenes derivatives with moderate to good yields. Results: The desired 1,2-diarylethylenes were obtained in 46-96% yields via Pd(0)-catalyzed one-pot reaction of benzyl halides, tosylhydrazide, and aryl aldehydes. Conclusion: The catalytic system presented here enables the use of easily accessible starting materials and good functional group tolerance.
Determining the excited-state substituent constants of furyl and thienyl groups
Qu, Junyan,Cao, Chao-Tun,Cao, Chenzhong
supporting information, (2018/04/24)
Six series of styrene derivatives XCH═CHArY (total of 65) containing the styrene parent molecular skeleton were synthesized (here, Y is OMe, Me, H, F, Cl, CF3, CN, and NO2, and X is 2-furyl, 3-furyl, 2′-methyl-2-furyl, 2-thienyl, 3-thienyl, and 2′-methyl-2-theniyl). Their ultraviolet absorption spectra were measured in anhydrous ethanol, and their wavelength of absorption maximum λmax was recorded. For the wavenumber νmax (cm?1, νmax?=?1/λmax) of the obtained λmax, a quantitative correlation analysis was performed, and 6 excited-state substituent constants σexcc(p) of groups X were obtained by means of curve-fitting method. Taking the νmax values of total 90 compounds of styrene derivatives as a data set (including 25 compounds from reference and 65 compounds of this work), a quantitative correlation analysis was performed, and the reliability of the obtained σexcc(p) was verified. In addition, 12 samples of disubstituted Schiff bases (XCH═NArY) involving the above groups X were synthesized, and their νmax values were recorded. Using these 12 νmax together with the 14 νmax values of Schiff bases taken from reference (total of 26 compounds), it was further verified that the σexcc(p) values are reliable by means of quantitative correlation method.
