7042-34-4Relevant academic research and scientific papers
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
supporting information, p. 242 - 246 (2021/01/13)
Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.
Design, synthesis and antitumor activity evaluation of Chrysamide B derivatives
Zhu, Longqing,Li, Junfang,Fan, Xiaohong,Hu, Xiaoling,Chen, Jinhong,Liu, Yonghong,Hao, Xiangyong,Shi, Tao,Wang, Zhen,Zhao, Quanyi
, (2021/04/29)
Marine natural products derived from special or extreme environment provide an important source for the development of anti-tumor drugs due to their special skeletons and functional groups. In this study, based on our previous work on the total synthesis and structure revision of the novel marine natural product Chrysamide B, a group of its derivatives were designed, synthesized, and subsequently of which the anti-cancer activity, structure-activity relationships and cellular mechanism were explored for the first time. Compared with Chrysamide B, better anti-cancer performance of some derivatives against five human cancer cell lines (SGC-7901, MGC-803, HepG2, HCT-116, MCF-7) was observed, especially for compound b-9 on MGC-803 and SGC-7901 cells with the IC 50 values of 7.88 ± 0.81 and 10.08 ± 1.08 μM, respectively. Subsequently, cellular mechanism study suggested that compound b-9 treatment could inhibit the cellular proliferation, reduce the migration and invasion ability of cells, and induce mitochondrial-dependent apoptosis in gastric cancer MGC-803 and SGC-7901 cells. Furthermore, the mitochondrial-dependent apoptosis induced by compound b-9 is related with the JAK2/STAT3/Bcl-2 signaling pathway. To conclude, our results offer a new structure for the discovery of anti-tumor lead compounds from marine natural products.
METHOD FOR ALCOHOLYSIS OF AMIDE
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Paragraph 0041-0042; 0044-0066; 0075-0077; 0087-088; 0129-01, (2020/03/01)
Provided is a method for the alcoholysis of an amide. The method comprises subjecting an amide-containing compound to alcoholysis under alkaline conditions using an epoxy compound as an accelerant of alcoholysis.
Selective hydrogenation of α,β-unsaturated carbonyl compounds on silica-supported copper nanoparticles
Mendes-Burak, Jorge,Ghaffari, Behnaz,Copéret, Christophe
supporting information, p. 179 - 181 (2019/01/04)
Silica-supported copper nanoparticles prepared via surface organometallic chemistry are highly efficient for the selective hydrogenation of various α,β-unsaturated carbonyl compounds yielding the corresponding saturated esters, ketones, and aldehydes in the absence of additives. High conversions and selectivities (>99%) are obtained for most substrates upon hydrogenation at 100-150 °C and under 25 bar of H2.
Scalable Preparation of Methylated Ando-Type Horner-Wadsworth-Emmons Reagent
Bressin, Robert K.,Driscoll, Julia L.,Wang, Yanping,Koide, Kazunori
, p. 274 - 277 (2019/02/14)
The Horner-Wadsworth-Emmons (HWE) reactions are vital to the chemical synthesis of complex molecules, forging a carbon-carbon double bond in the generation of α,β-unsaturated enoates from aldehydes or ketones. Despite their frequent use, the Z-stereoselective formation of α,β-unsaturated esters from aldehydes have been mostly limited to the use of the commercially available Still-Gennari reagent. Ando developed an alternative reagent to achieve the same formation with less expensive reagents. However, an α-methylated Ando-HWE reagent has remained difficult to prepare, hindering a reliable route to α,β-disubstituted Z-enoates. Here, we report the development of a preparative synthesis of a methylated Ando-HWE reagent for the highly Z-selective HWE reaction. Costing $0.49/mmol, this synthesis is significantly cheaper than the currently available Still-Gennari reagent ($11/mmol, Millipore Sigma 2018). The purification procedure does not require chromatography, with recrystallization as the only purification method, making it highly amenable to large-scale production.
Dianionic Phase-Transfer Catalyst for Asymmetric Fluoro-cyclization
Egami, Hiromichi,Niwa, Tomoki,Sato, Hitomi,Hotta, Ryo,Rouno, Daiki,Kawato, Yuji,Hamashima, Yoshitaka
supporting information, p. 2785 - 2788 (2018/03/08)
Inspired by the dicationic nature of the electrophilic fluorinating reagent, Selectfluor (1), we rationally designed a series of dicarboxylic acid precatalysts (2), which, when deprotonated, act as anionic phase-transfer catalysts for asymmetric fluorination of alkenes. Among them, 2a having the shortest linker moiety efficiently catalyzed unprecedented 6-endo-fluoro-cyclization of various allylic amides, affording fluorinated dihydrooxazine compounds with high enantioselectivity (up to 99% ee). In addition to cyclic substrates, acyclic trisubstituted alkenes underwent the reaction with good diastereoselectivity, whereas low diastereoselectivity was observed for linear disubstituted alkenes. Results suggest that the reaction proceeds via a fluoro-carbocation intermediate.
Hydrodebromination of allylic and benzylic bromides with water catalyzed by a rhodium porphyrin complex
Yang, Wu,Chen, Chen,Chan, Kin Shing
, p. 12879 - 12883 (2018/10/02)
Hydrodebromination of allylic and benzylic bromides was successfully achieved by a rhodium porphyrin complex catalyst using water as the hydrogen source without a sacrificial reductant. Mechanistic investigations suggest that bromine atom abstraction via a rhodium porphyrin metalloradical operates to give the rhodium porphyrin alkyl species and the subsequent hydrolysis of the rhodium porphyrin alkyl species to a hydrocarbon product is a key step to harness the hydrogen from water.
Heck and oxidative boron Heck reactions employing Pd(II) supported amphiphilized polyethyleneimine-functionalized MCM-41 (MCM-41@aPEI-Pd) as an efficient and recyclable nanocatalyst
Motevalizadeh, Seyed Farshad,Alipour, Masoumeh,Ashori, Fatemeh,Samzadeh-Kermani, Alireza,Hamadi, Hosein,Ganjali, Mohammad Reza,Aghahosseini, Hamideh,Ramazani, Ali,Khoobi, Mehdi,Gholibegloo, Elham
, (2017/10/23)
A novel nanocatalyst was developed based on covalent surface functionalization of MCM-41 with polyethyleneimine (PEI) using [3-(2,3-Epoxypropoxy)propyl] trimethoxysilane (EPO) as a cross-linker. Amine functional groups on the surface of MCM-41 were then conjugated with iodododecane to render an amphiphilic property to the catalyst. Palladium (II) was finally immobilized onto the MCM-41@PEI-dodecane and the resulted MCM-41@aPEI-Pd nanocatalyst was characterized by FT-IR, TEM, ICP-AES and XPS. Our designed nanocatalyst with a distinguished core-shell structure and Pd2+ ions as catalytic centers was explored as an efficient and recyclable catalyst for Heck and oxidative boron Heck coupling reactions. In Heck coupling reaction, the catalytic activity of MCM-41@aPEI-Pd in the presence of triethylamine as base led to very high yields and selectivity. Meanwhile, the MCM-41@aPEI-Pd as the first semi-heterogeneous palladium catalyst was examined in the C-4 regioselective arylation of coumarin via the direct C-H activation and the moderate to excellent yields were obtained toward different functional groups. Leaching test indicated the high stability of palladium on the surface of MCM-41@aPEI-Pd as it could be recycled for several runs without significant loss of its catalytic activity.
Method for amide alcoholysis
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Paragraph 0049; 0040; 0051; 0122; 0123; 0124; 0139-0142, (2017/12/28)
The invention provides a method for amide alcoholysis. The method comprises the following steps: using an epoxy compound as an accelerator, and performing alcoholysis on an amide-containing compound under an alkaline condition. The above method is convenient and easy to operate, pure products can be obtained through post-treatment which just needs conventional separation steps, and the epoxy compound is low in costs, thus production and operation costs and three wastes (waste water, waste gas and solid waste) treatment risks and costs can be greatly reduced; when the above method is used, reaction conditions are mild, the method can be compatible with various substituent groups and functional groups, obtains good yields aiming at various amides with different structures, and is wide in substrate application range; an environmentally friendly, economic and practical high-efficiency method for conversion of amides into more useful esters is provided; and the above alcoholysis reaction cannot be influenced by impurities of a previous-step C-H activating reaction system, an intermediate purification step is saved, and two-step reactions of a C-H activating reaction and an amide alcoholysis reaction can be linked.
An Epoxide-Mediated Deprotection Method for Acidic Amide Auxiliary
Pei, Qing-Lan,Che, Guan-Da,Zhu, Ru-Yi,He, Jian,Yu, Jin-Quan
supporting information, p. 5860 - 5863 (2017/11/10)
A practical method for the removal of a versatile acidic amide auxiliary has been developed. Facile alcoholysis of the amide in the presence of KOAc is enabled by an epoxide, which mechanistically resembles the removal of the Myers' auxiliary. The protocol has been applied to the removal of a variety of amide substrates and their C-H functionalization products with high efficiency and low cost, representing a step forward toward the development of a versatile directing group for C-H activation.
