1845-30-3Relevant academic research and scientific papers
Individual stereoisomers of verbenol and verbenone express bioactive features
Ivanov, Marija,Kovalenko, Vitaly,Svirid, Anastasia,Kosti?, Marina,Petrovi?, Jovana,Stojkovi?, Dejan
, (2021/12/13)
Naturally occurring terpene core compounds have been used extensively in both pharmaceutical and cosmetic industry. However, since chirality of these compounds has profound influence on the level of their bioactivity, the aim of the present study was to a
Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst
Aberkouks, Abderrazak,Mekkaoui, Ayoub Abdelkader,Ait Ali, Mustapha,El Firdoussi, Larbi,El Houssame, Soufiane
, (2020/02/15)
Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.
Stereospecific synthesis of S-(?)-trans-verbenol and its antipode by inversion of sterically hindered alcohols
Fang, Jia-Xing,Kong, Xiang-Bo,Liu, Fu,Zhang, Su-Fang,Zhang, Zhen
, (2020/12/15)
S-(?)-trans-Verbenol (1) and its antipode, R-(+)-trans-verbenol (1′) have been confirmed as the critical pheromone components of bark beetles. Synthesis of these two active secondary alcohols (1 and 1′) from commercially available starting materials S-α-pinene and R-α-pinene was reported. The key steps were mainly depended on the effective SN2 stereo-inversion of the hydroxy group of sterically hindered alcohols (3 and 3′), using Mitsunobu reaction or hydrolysis of mesylate ester, alternatively. Our results provide a new and stereo-selectivity way to obtain optically active insect pheromones.
Cis-dioxidomolybdenum(VI) complexes with chiral tetradentate Schiff bases: Synthesis, spectroscopic characterization and catalytic activity in sulfoxidation and epoxidation
Karman, Marta,Romanowski, Grzegorz
, (2020/07/02)
New chiral mononuclear cis-dioxidomolybdenum(VI) complexes, MoO2L1-MoO2L7, have been synthesized by the reaction of MoO2(acac)2 with tetradentate Schiff bases derived from various substitut
A Cu-Doped ZIF-8 metal organic framework as a heterogeneous solid catalyst for aerobic oxidation of benzylic hydrocarbons
Nagarjun, Nagarathinam,Dhakshinamoorthy, Amarajothi
, p. 18702 - 18712 (2019/12/09)
Mixed-metal metal organic frameworks have received considerable attention in recent years and it has been shown that the activity of the parent metal organic framework (MOF) is often enhanced upon doping with external metal ions within the framework. In this context, Cu2+ ions with different loadings were incorporated within the ZIF-8 framework to obtain a series of Cu-doped ZIF-8 materials and their activity was examined in the aerobic oxidation of hydrocarbons. The as-synthesized Cu-doped solids were characterized by powder X-ray diffraction (XRD), ultraviolet diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM), Fourier Transform infrared (FT-IR), electron paramagnetic resonance (EPR) and inductively coupled plasma (ICP) analysis. The experimental results revealed that the activity of Cu-doped ZIF-8 is much higher than that of the parent ZIF-8 in all the tested substrates at 120 °C. Furthermore, the activity of the Cu-doped ZIF-8 with the highest Cu loading was eight fold higher than that of the parent ZIF-8 in the aerobic oxidation of cyclooctane (1) at 120 °C with more than 80% selectivity to the corresponding cyclooctanol/cyclooctanone (ol/one) mixture. Cu-doped ZIF-8 was reused two times with no significant drop in its activity under identical conditions. Furthermore, comparison of the two times reused solid with that of the fresh solid by powder XRD and SEM analysis revealed identical structural integrity and morphology, respectively during the oxidation reactions.
Oxy-functionalization of olefins with neat and heterogenized binuclear V(IV)O and Fe(II)complexes: Effect of steric hindrance on product selectivity and output in homogeneous and heterogeneous phase
Parmar, Digvijaysinh K.,Butani, Pinal M.,Thumar, Niraj J.,Jasani, Pinal M.,Padaliya, Ravi V.,Sandhiya, Paba R.,Nakum, Haresh D.,Khan, Md. Nasim,Makwana, Dipak
, (2019/06/05)
Neat {[VO(sal2bz)]2; [Fe(sal2bz)(H2O)2]2·2H2O} and zeolite-Y immobilized {[VO(sal2bz)]2-Y; [Fe(sal2bz)(H2O)2]2-Y} binuclear complexes have been prepared and characterized by spectroscopic techniques (IR, UV–vis), elemental analyses (CHN, ICP-OES), thermal study (TGA), scanning electron micrograph (SEM), adsorption study (BET)and X-ray diffraction (XRD)patterns. Neat (homogeneous)and immobilized (heterogeneous)complexes were employed as catalysts in the oxidation of olefins, namely, cyclohexene, limonene and α-pinene in the presence of 30% hydrogen peroxide. 100% conversion of cyclohexene and α-pinene was obtained while limonene was oxidized up to 90%. Homogeneous catalysts showed highly selective result as neat [VO(sal2bz)]2 complex has provided 87% cyclohexane-1,2-diol and neat [Fe(sal2bz)(H2O)2]2·2H2O complex has provided 79% verbenone in oxidation of cyclohexene and α-pinene, respectively. We have observed that due to steric hindrance, formation of olefinic oxidation products increases on moving from α-pinene to limonene and limonene to cyclohexene. Additionally. recovered heterogeneous catalysts showed intact results up to two consecutive runs. Probable catalytic mechanism has been proposed for oxidation of cyclohexene.
Green and simple preparation method for synthesizing (-)-trans-verbenol and enantiomer (+)-trans-verbenol thereof
-
Paragraph 0024; 0025; 0026, (2019/09/13)
The invention provides a green and simple preparation method for synthesizing (-)-trans-verbenol and enantiomer (+)-trans-verbenol thereof. The method is characterized by comprising the following steps: using (-)-cis-verbenol and (+)-cis-verbenol, utilizing a Mitsunobu reaction, and performing hydroxyl configuration inversion so as torespectively obtain the (-)-trans-verbenol and (+)-trans-verbenol, wherein the yield of the (-)-trans-verbenol is 81%, and the yield of the (+)-trans-verbenol is 80%. The synthetic method in the invention comprises novel, effective and environment-friendly steps and procedures. Compared with the conventional trans-verbenol synthesis method, the method disclosed by the invention avoids use of lead tetraacetate (an oxidizing agent) and benzene toxic solvents. The raw trans-verbenol can be prepared by alpha-pinene oxidation, and the (-)-trans-verbenol and (+)-trans-verbenol can be used for controlling bark beetles in China.
Cobalt-Catalyzed Hydroboration of Alkenes, Aldehydes, and Ketones
Tamang, Sem Raj,Bedi, Deepika,Shafiei-Haghighi, Sara,Smith, Cecilia R.,Crawford, Christian,Findlater, Michael
, p. 6695 - 6700 (2018/11/21)
An operationally convenient and general method for hydroboration of alkenes, aldehydes, and ketones employing Co(acac)3 as a precatalyst is reported. The hydroboration of alkenes in the presence of HBpin, PPh3, and NaOtBu affords good to excellent yields with high Markovnikov selectivity with up to 97:3 branched/linear selectivity. Moreover, Co(acac)3 could be used effectively to hydroborate aldehydes and ketones in the absence of additives under mild reaction conditions. Inter- and intramolecular chemoselective reduction of the aldehyde group took place over the ketone functional group.
Zeolite Y encaged Ru(III) and Fe(III) complexes for oxidation of styrene, cyclohexene, limonene, and α-pinene: An eye-catching impact of H2SO4 on product selectivity
Godhani, Dinesh R.,Nakum, Haresh D.,Parmar, Digvijaysinh K.,Mehta, Jignasu P.,Desai, Nisheeth C.
, p. 223 - 237 (2016/12/09)
A novel Ru(III) and Fe(III) complexes of ligands 1 and/or 2 {where 1 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene))diphenol and 2 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene)) bis(4-nitrophenol)} have been synthesized as ‘neat’ and zeolite Y encapsulated complexes. These catalysts are characterized by various analytical tools such as FTIR, UV–vis, elemental analysis, ICP-AES, molar conductivity, 1H- and 13C NMR, TGA, SEM, AAS, BET, magnetic susceptibility and powder XRD to endorse the complex formation, absence of peripheral redundant ligands and complexes, conservation of zeolite Y morphology and crystallinity, and the encapsulation of complexes without devastation in the zeolite Y framework. Out of these synthesized catalysts, 5Y is found to be a potent candidate for styrene (Conv. 76.1%, TOF: 2130 h?1), cyclohexene (Conv. 84.4%, TOF: 2351 h?1), limonene (Conv. 81.6%, TOF: 2273 h?1), and α-pinene (Conv. 72.6%, TOF: 2023 h?1) oxidation with high selectivity of respective allylic products excluding the styrene oxidation, which undergoes epoxidation only. The addition of H2SO4 in an identical reaction catalyzed by 5Y not only surge the conversion up to 100% in a short time span with high TOF but also increase the selectivity of respective epoxidation products. This switchover in the selectivities could be credited to the presence of H2SO4 that facilitates the heterolytic [sbnd]O[sbnd]O[sbnd] bond cleavage of metal hydroperoxide and stimulates the epoxidation over allylic oxidation. Furthermore, the results establish that the heterogeneous systems are effortlessly recovered and reused without ample drop in the activity and selectivity.
Catalytic Activity of Crystallographically Characterized Organic–Inorganic Hybrid Containing 1,5-Di-amino-pentane Tetrachloro Manganate with Perovskite Type Structure
Mondal, Paramita,Abdel-Aal, Seham Kamal,Das, Debasis,Islam, Sk Manirul
, p. 2332 - 2339 (2017/08/22)
Abstract: Layered 2D organic–inorganic hybrid perovskite (OIHS) of the diammonium series, 1,5 di-aminepentane tetrachloro mangenate ([NH3–(CH2)5–NH3] MnCl4) was prepared by slow evaporation and reducing temperature method and characterized by single crystal X-ray diffraction analysis. Its structure consists of organic cation, [NH3(CH2)5NH3]+2 extended in a zigzag fashion and inorganic anion, [MnCl6]?2 where Mn2+ is coordinated by six Cl? ion in octahedral fashion. The organic and inorganic segments are alternately stacked along c-axis where inorganic layer is extended through corner-shared octahedra sandwiched by the di-aminopentane molecules. The layers (organic and inorganic) were connected to each other through N–HCl hydrogen bonds and van-der Waals interaction to build cation–anion–cation cohesion. The hybrid crystal had orthorhombic non-centrosymetric system having I212121 space group with unit cell parameters a = 7.1742(3) ?, b = 7.3817(3) ?, c = 23.9650(10) ?, V = 1269.13 ?3 and Z = 4. The hybrid exhibited excellent catalytic activity towards sulphide and alkene oxidation using aqueous H2O2 as an oxidant. Graphical Abstract: OIHS of the diammonium series [NH3–(CH2)5–NH3] MnCl4; 1,5 di-aminepentane tetrachloro mangenate were prepared by slow evaporation and temperature decrease method, characterized by single crystal X-ray diffraction. This complex exhibits excellent catalytic activity towards sulphide oxidation and alkene oxidation using aqueous H2O2 as an oxidant. [Figure not available: see fulltext.].
