2883-98-9Relevant academic research and scientific papers
Sustainable Synthesis of the Naturally Hypolipidemic Agent α-Asarone
Camacho-Dávila, Alejandro A.,Chávez-Flores, David,Zaragoza-Galán, Gerardo,Ramos-Sánchez, Víctor H.
, p. 1669 - 1674 (2015)
(Chemical Equation Presented). A short and practical preparation of α-asarone was developed using the inexpensive methylisoeugenol as a starting material. The utilization of a sequence of tribromination, debromination, and copper-mediated aromatic substitution enabled the stereoselective formation of only the E-isomer of α-asarone in good yield.
Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins
Yang, Biao,Dong, Kui,Li, Xiang-Sheng,Wu, Li-Zhu,Liu, Qiang
supporting information, p. 2040 - 2044 (2022/03/17)
An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.
A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
, p. 6684 - 6690 (2021/05/31)
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
Cobalt-Catalyzed Z to e Isomerization of Alkenes: An Approach to (E)-β-Substituted Styrenes
Liu, Hongmei,Xu, Man,Cai, Cheng,Chen, Jianhui,Gu, Yugui,Xia, Yuanzhi
supporting information, p. 1193 - 1198 (2020/02/04)
An efficient cobalt-catalyzed Z to E isomerization of β-substituted styrenes using the amido-diphosphine ligand was developed, delivering the (E)-isomers with good functional tolerance and high stereoselectivity. The reaction could be scaled up to gram-scale with a catalyst loading of 0.1 mol %, using a mixture of (Z)- and (E)-alkene as the starting material. Preliminary mechanistic studies indicated that cobalt(I)-hydride and a benzylic-cobalt species were probably involved in the reaction, as supported by experiments and DFT calculations.
Green and simple preparation process of alpha-asarone
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Paragraph 0044; 0051-0053; 0054; 0061-0063, (2019/10/01)
The invention relates to the technical field of medicine, in particular to a green and simple preparation process of alpha-asarone. 1,2,4-trimethoxybenzene is adopted as a raw material, and three steps, namely, an acylation reaction, a reduction reaction and a dehydration reaction are included. Through the preparation process of alpha-asarone, the total yield can reach 62.3% or above, all organicsolvents can be recycled repeatedly, and the process has the advantages of low cost, small pollution, safe and convenient operation, high yield and the like.
Preparation and purification method α . (by machine translation)
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Paragraph 0047-0058, (2019/09/13)
The invention relates to the technical field of medicine . The α - asarum is a preparation and purification method. (1) The following steps: (2) adding the cis-trans α / β-asarine mixture into an organic solvent, adding a stabilizer to reflux the water, distilling off the solvent; and distilling, in step 1, rectifying the solvent and continuously discharging trace nitrogen, respectively, into the rectification material in a reduced-pressure rectification process to collect the distillation head, respectively. Main fraction, distillate; (3) Step 2, the distilled main fraction is added with a solvent chromatography, and the precipitate is crystallized under nitrogen with anhydrous methanol or petroleum ether to yield a high purity α - asarone powder product. In addition, the method is easy and convenient to operate, the raw material cost is 98% low, α -asarum yield 0.62% is high, and industrial mass production is easy to realize. α - asarone. (by machine translation)
Synthetic process of alpha-asarone
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Paragraph 0033; 0036; 0037; 0041; 0042, (2018/11/22)
The invention belongs to the technical field of medicine and concretely relates to a synthetic process of alpha-asarone. In the dehydration elimination reaction stage of the synthetic process of alpha-asarone, propionic anhydride, anhydrous propionic acid or the mixed solution of propionic acid and propionic anhydride is selected as a dehydrating agent. The molar mass ratio of 2,4,5-trimethoxybenzene propyl alcohol to the dehydrating agent is 1:(0.1-20). Anhydrous sodium propionate or anhydrous potassium propionate is a dehydration catalyst. The molar mass ratio of 2,4,5-trimethoxybenzene propyl alcohol to the catalyst is 1:(0.1-2). The process provided by the invention can greatly improve the yield of alpha-asarone and inhibit the formation of beta-asarone and the formation of impuritiessuch as asarone polymers, and reduce the cost. The synthetic process is suitable for industrial production of alpha-asarone.
Larvicidal and structure-activity studies of natural phenylpropanoids and their semisynthetic derivatives against the tobacco armyworm Spodoptera litura (Fab.) (Lepidoptera: Noctuidae)
Bhardwaj, Anu,Tewary, Dhananjay Kumar,Kumar, Rakesh,Kumar, Vinod,Sinha, Arun Kumar,Shanker, Adarsh
experimental part, p. 168 - 177 (2010/04/29)
The larvicidal activity of 18 phenylpropanoids, 1-18, including phenylpropenoate, phenylpropenal, phenylpropene, and their semisynthetic analogues, were evaluated against the tobacco armyworm, Spodoptera litura (FAB.), to identify promising structures with insecticidal activity. Amongst various phenylpropanoids, isosafrole, a phenylpropene, showed the best activity, with an LC50 value of 0.6 μg/leaf cm2, followed by its hydrogenated derivative dihydrosafrole (LC50=2.7 μg/leaf cm 2). The overall larvicidal activity of various phenylpropene derivatives was observed in the following order: isosafrole (6) >dihydrosafrole (16)>safrole (12)>anethole (4)>methyl eugenol (11)>eugenol (13)>β-asarone (8)>dihydroasarone (18)>dihydroanethole (15). Dihydrosafrole might be a promising compound, although presenting a lower larvicidal activity than isosafrole, because of its better stability and resistance to oxidative degradation (due to the removal of the extremely reactive olefinic bond) in comparison to isosafrole. Such structure-activity relationship studies promote the identification of lead structures from natural sources for the development of larvicidal products against S. litura and related insect pests.
Role of the methoxy group in product formation via TiCl 4 promoted 4-phenyldioxolane isomerizations
Green, Ivan R.,October, Natasha
experimental part, p. 71 - 96 (2010/07/20)
The product distribution obtained from the TiCl 4 initiated intramolecular isomerizations of 4-methoxyphenyl-and trimethoxyphenyldioxolanes at -78 °C, -30 °C and 0 °C provided insights into the important regiochemical role played by these groups in such Mukaiyama-type rearrangements through their resonance effects on the aryl ring of the dioxolanes. ARKAT USA, Inc.
