905451-26-5Relevant academic research and scientific papers
Ball-Milling-Enabled Reactivity of Manganese Metal**
Bolt, Robert R. A.,Browne, Duncan L.,Howard, Joseph L.,Khan, Adam,Magri, Giuseppina,Morrill, Louis C.,Nicholson, William I.,Richards, Emma,Seastram, Alex C.
supporting information, p. 23128 - 23133 (2021/09/20)
Efforts to generate organomanganese reagents under ball-milling conditions have led to the serendipitous discovery that manganese metal can mediate the reductive dimerization of arylidene malonates. The newly uncovered process has been optimized and its mechanism explored using CV measurements, radical trapping experiments, EPR spectroscopy, and solution control reactions. This unique reactivity can also be translated to solution whereupon pre-milling of the manganese is required.
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes: Scope and limitations
Kazia, Armands,Melngaile, Renate,Mishnev, Anatoly,Veliks, Janis
supporting information, p. 1384 - 1388 (2020/03/03)
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes utilizing S-monofluoromethyl-S-phenyl-2,3,4,5-tetramethylphenylsulfonium tetrafluoroborate is an efficient approach to obtain a range of monofluorocyclopropane derivatives. So far, fluoromethylsulfonium salts have displayed the broadest scope for direct fluoromethylene transfer. In contrast to more commonly used fluorohalomethanes or freon derivatives, diarylfluoromethylsulfonium salts are bench stable, easy-to use reagents useful for the direct transfer of a fluoromethylene group to alkenes giving access to the challenging products-fluorocyclopropane derivatives. Interplay between the reactivity of the starting materials and stability of the fluorocyclopropanes formed determines the outcome of the process.
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
Coutant, Eloi P.,Hervin, Vincent,Gagnot, Glwadys,Ford, Candice,Baatallah, Racha,Janin, Yves L.
supporting information, p. 2853 - 2860 (2018/11/26)
We have explored here the scope of the age-old diethyl malonate-based accesses to α-amino esters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered. The synthetic modifications of some of the intermediates - using Suzuki-Miyaura coupling or cycloadditions - before undertaking the oximation step - provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β-bromo-α-hydroxyiminocarboxylate and various alkylfuranes.
Design, synthesis, and biological evaluation of some novel indolizine derivatives as dual cyclooxygenase and lipoxygenase inhibitor for anti-inflammatory activity
Shrivastava, Sushant K.,Srivastava, Pavan,Bandresh, Robin,Tripathi, Prabhash Nath,Tripathi, Avanish
, p. 4424 - 4432 (2017/07/22)
Some novel indolizine derivatives were synthesized by bioisosteric modification of imidazo[1,2-a]pyridine for anti-inflammatory activity. The physicochemical characterization and structure of compounds were elucidated by state of the art spectroscopic technique. Induced fit docking was performed for initial screening to elucidate the interactions with corresponding amino acids of cyclooxygenase (COX-1, COX-2) and lipoxygenase (LOX) enzymes. The target compounds 53–60 were then evaluated against in vivo carrageenan and arachidonic acid induced rat paw edema models for anti-inflammatory activity. Amongst all the synthesized derivatives, compound 56 showed the significant anti-inflammatory activity in both rat paw edema models with very less ulcerogenic liability in comparison to standard diclofenac, celecoxib, and zileuton. The compounds 56 was further assessed to observe in vitro enzyme inhibition assay on both cyclooxygenase and lipoxygenase enzyme where it showed a preferential and selective non-competitive enzyme inhibition towards the COX-2 (IC50?=?14.91?μM, Ki?=?0.72?μM) over COX-1 (IC50?>?50?μM) and a significant non-competitive inhibition of soybean lipoxygenase enzyme (IC50?=?13.09?μM, Ki?=?0.92?μM). Thus, in silico, in vivo, and in vitro findings suggested that the synthesized indolizine compound 56 has a dual COX-2 and LOX inhibition characteristic and parallel in vivo anti-inflammatory activity in comparison to the standard drugs.
Determination of thermodynamic affinities of various polar olefins as hydride, hydrogen atom, and electron acceptors in acetonitrile
Cao, Ying,Zhang, Song-Chen,Zhang, Min,Shen, Guang-Bin,Zhu, Xiao-Qing
, p. 7154 - 7168 (2013/08/23)
A series of 69 polar olefins with various typical structures (X) were synthesized and the thermodynamic affinities (defined in terms of the molar enthalpy changes or the standard redox potentials in this work) of the polar olefins obtaining hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the polar olefins (X ?-) obtaining protons and hydrogen atoms, and the thermodynamic affinities of the hydrogen adducts of the polar olefins (XH?) obtaining electrons in acetonitrile were determined using titration calorimetry and electrochemical methods. The pure Ci - 'C π-bond heterolytic and homolytic dissociation energies of the polar olefins (X) in acetonitrile and the pure Ci - 'C π-bond homolytic dissociation energies of the radical anions of the polar olefins (X?-) in acetonitrile were estimated. The remote substituent effects on the six thermodynamic affinities of the polar olefins and their related reaction intermediates were examined using the Hammett linear free-energy relationships; the results show that the Hammett linear free-energy relationships all hold in the six chemical and electrochemical processes. The information disclosed in this work could not only supply a gap of the chemical thermodynamics of olefins as one class of very important organic unsaturated compounds but also strongly promote the fast development of the chemistry and applications of olefins.
Nickel(ii)-catalyzed enantioselective 1,3-dipolar cycloaddition of azomethine imines with alkylidene malonates
Li, Jiangting,Lian, Xiangjin,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
supporting information, p. 5134 - 5140 (2013/07/05)
We demonstrated an asymmetric 1,3-dipolar cycloaddition of azomethine betaines with alkylidene malonates by using a chiral N,N'-dioxide- NiII complex as a catalyst. Both aromatic- and aliphatic-substituted alkylidene malonates were found to be suitable for the reaction. A range of transpyrazolone derivatives was exclusively obtained with excellent yields (up to 99% yield) and good enantioselectivities (up to 97% ee) under mild reaction conditions. The reaction could be carried out on a gram scale with the good results being maintained. Control experiments were performed to elucidate the specific diastereoselectivity of the reaction. The formation of single trans isomers was dominated by secondary orbital interactions between the ester groups of the dipolarophile and the azomethine imine. On the basis of the experimental results and previous reports, a possible catalytic model was assumed.
Chiral-Zn(NTf2)2-complex-catalyzed diastereo- and enantioselective direct conjugate addition of arylacetonitriles to alkylidene malonates
Yao, Jingjing,Liu, Xiaohua,He, Peng,Zhu, Yin,Lian, Xiangjin,Lin, Lili,Feng, Xiaoming
supporting information, p. 16424 - 16430 (2013/12/04)
Chiral N,N′-dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate-to-good yields with high diastereoselectivities (82:18->99:1 d.r.) and enantioselectivities (81-99 % ee). The reactions performed well, owing to the high Lewis acidity of the metal triflimidate and a ligand-acceleration effect. The N,N′-dioxide also benefited the deprotonation process as a Bronsted base. The catalytic reaction could be performed on the gram-scale with retention of yield, diastereoselectivity, and enantioselectivity. The products that contained functional groups were ready for further manipulation. In addition, a possible catalytic model was proposed to explain the origin of the asymmetric induction. Copyright
A convenient synthesis of the (E)-monoacetates of 2-alkylidenepropane-1,3- diols
Miura, Tsuyoshi,Okazaki, Kenjiro,Ogawa, Kyoko,Otomo, Erika,Umetsu, Satoe,Takahashi, Mauko,Kawashima, Yuya,Jyo, Yuki,Koyata, Naka,Murakami, Yasuoki,Imai, Nobuyuki
experimental part, p. 2695 - 2700 (2009/04/04)
Various kinds of 3-substituted (E)-2-(hydroxymethyl)prop-2-enyl acetates were conveniently obtained in excellent yields by the regiospecific acetylation of 2-alkylidenepropane-1,3-diols with 10 equivalents of vinyl acetate in the presence of 50% w/w porcine pancreatic lipase (PPL) type II; the starting materials or (Z)-monoacetate or diacetate byproducts were generally not present. Georg Thieme Verlag Stuttgart.
A facile experimental method to determine the hydride affinity of polarized olefins in acetonitrile
Zhu, Xiao-Qing,Zhang, Min,Liu, Qiao-Yun,Wang, Xiao-Xiao,Zhang, Jian-Yu,Cheng, Jin-Pei
, p. 3954 - 3957 (2007/10/03)
(Chemical Equation Presented) Choosing a suitable hydride reducing agent and thermodynamic analysis of reduction mechanisms is facilitated by experimental hydride affinities ΔHH-A, which are reported herein for 28 polarized olefins 1 in acetonitrile (see scheme). The method should also be applicable to ketones, aldehydes, and imines.
