25067-61-2Relevant articles and documents
Manganese(I)-Catalyzed H-P Bond Activation via Metal-Ligand Cooperation
Pérez, Juana M.,Postolache, Roxana,Casti?eira Reis, Marta,Sinnema, Esther G.,Vargová, Denisa,De Vries, Folkert,Otten, Edwin,Ge, Luo,Harutyunyan, Syuzanna R.
supporting information, p. 20071 - 20076 (2021/12/03)
Here we report that chiral Mn(I) complexes are capable of H-P bond activation. This activation mode enables a general method for the hydrophosphination of internal and terminal α,β-unsaturated nitriles. Metal-ligand cooperation, a strategy previously not considered for catalytic H-P bond activation, is at the base of the mechanistic action of the Mn(I)-based catalyst. Our computational studies support a stepwise mechanism for the hydrophosphination and provide insight into the origin of the enantioselectivity.
Method for preparing (methyl) acrylonitrile by dehydration of (methyl) acrylamide
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Paragraph 0025-0093, (2019/12/11)
The invention relates to the field of fine chemical industry, and in particular relates to a method for preparing (methyl) acrylonitrile by dehydration of (methyl) acrylamide. The method for preparingthe (methyl) acrylonitrile by dehydration of secondary catalytic raw material (methyl) acrylamide comprises the following steps: firstly, carrying out dehydration reaction on the (methyl) acrylamidein a homogeneous system, and then carrying out secondary catalytic dehydration reaction in a reaction bed by using a mesoporous organometallic palladium catalyst. The method can reduce the generationof waste water and waste, and has relatively higher (methyl) acrylamide conversion rate and higher (methyl) acrylonitrile single-pass yield. The method has mild reaction conditions, rapid reaction, simple process and easy operation, and is suitable for industrial production.
The Effect of Viscosity on the Diffusion and Termination Reaction of Organic Radical Pairs
Li, Xiaopei,Ogihara, Tasuku,Abe, Manabu,Nakamura, Yasuyuki,Yamago, Shigeru
, p. 9846 - 9850 (2019/07/10)
The effect of viscosity on the diffusion efficiency (Fdif) of an organic radical pair in a solvent cage and the termination mechanism, that is, the selectivity of disproportionation (Disp) and combination (Comb) of the geminated caged radical pair and the diffused radicals encountered, were investigated quantitatively by following the photolysis of dimethyl 2,2′-azobis(2-methylpropionate) (V-601) in the absence and presence of PhSD. Fdif and Disp/Comb selectivity outside the cage [Disp(dif)/Comb(dif)] are highly sensitive to the viscosity. In contrast, the Disp/Comb selectivity inside the cage [Disp(cage)/Comb(cage)] is rather insensitive. The difference in viscosity dependence between Disp(cage)/Comb(cage) and Disp(dif)/Comb(dif) is explained by the spin state of the radical pair inside and outside the cage and the spin state dependent configurational changes of the radical pair upon their collision. Given that the configurational change of the radicals associates the displacement and reorganization of solvents around the radicals, the termination outside the cage, which requires larger change than that inside the cage, is highly viscosity dependent. Furthermore, while the bulk viscosity of each solvent shows good correlation with Fdif and Disp/Comb selectivity, microviscosity is the better parameter predicting Fdif and Disp(dif)/Comb(dif) selectivity regardless of the solvents.
Synthesis and Structural Characterization of Nickel Complexes Possessing P-Stereogenic Pincer Scaffolds and Their Application in Asymmetric Aza-Michael Reactions
Yang, Zehua,Liu, Delong,Liu, Yangang,Sugiya, Masashi,Imamoto, Tsuneo,Zhang, Wanbin
supporting information, p. 1228 - 1237 (2015/04/27)
Novel P-stereogenic pincer-Ni complexes {κP,κC,κP-3,5-Me2-2,6-(MetBuPCH2)2C6H}NiCl (3), {κP,κC,κP-3,5-Me2-2,6-(MetBuPCH2)2C6H}NiOTf (4), [{κP,κN,κP-2,6-(MetBuPCH2)2C5H3N}NiCl]Cl (7), [{κP,κN,κP-2,6-(MetBuPCH2)2C5H3N}NiCl]BF4 (8), and [{κP,κN,κP-2,6-(MetBuPCH2)2C5H3N}Ni(NCMe)](BF4)2 (9) were synthesized in 55-84% yields and characterized by 1H NMR, 13C{1H} NMR, 31P{1H} NMR, 19F{1H} NMR, and/or single-crystal X-ray diffractions. The ORTEP diagrams of complexes 3, 7, 8, and 9 show that the coordination geometries around the Ni center in all these structures are approximately square planar but have different bond lengths and angles. These complexes were shown to be active catalysts for the asymmetric aza-Michael addition of α,β-unsaturated nitriles. For most examples good to excellent yields (up to 99%) and moderate enantiomeric excesses (up to 46% ee) were obtained. Notably, the PCP complex 3 exhibited higher catalytic activity in the aza-Michael addition than the PNP complexes 7, 8, and 9. Two achiral PCP-type pincer-Ni complexes, {κP,κC,κP-3,5-Me2-2,6-(tBu2PCH2)2C6H}NiCl (11) and {κP,κC,κP-3,5-Me2-2,6-(Ph2PCH2)2C6H}NiCl (13), were also synthesized and fully characterized in order to reveal the structural differences between the chiral and achiral complexes. (Chemical Equation Presented).
ALTERNATIVE SYNTHESIS OF 1,1-SUBSTITUTED OLEFINS HAVING ELECTRON-WITHDRAWING SUBSTITUENTS
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Page/Page column 7, (2012/12/13)
A three-stage method for synthesizing 1,1-disubstituted olefins is provided.
Dependence of thermal stability on molecular structure of RAFT/MADIX agents: A kinetic and mechanistic study
Zhou, Yanwu,He, Junpo,Li, Changxi,Hong, Linxiang,Yang, Yuliang
experimental part, p. 8446 - 8457 (2012/03/12)
The thermal decomposition of different classes of RAFT/MADIX agents, namely dithioesters, trithiocarbonates, xanthates, and dithiocarbamates, were investigated through heating in solution. It was found that the decomposition behavior is complicated interplay of the effects of stabilizing Z-group and leaving R-group. The mechanism of the decomposition is mainly through three pathways, i.e., β-elimination, α-elimination, and homolysis of dithiocarbamate (particularly for universal RAFT agent). The most important pathway is the β-elimination of thiocarbonylthio compounds possessing β-hydrogen, leading to the formation unsaturated species. For the leaving group containing solely α-hydrogen, such as benzyl, α-elimination takes place, resulting in the formation of (E)-stilbene through a carbene intermediate. Homolysis occurs specifically in the case of a universal RAFT agent, in which a thiocarbonyl radical and an alkylthio radical are generated, finally forming thiolactone through a radical process. The stabilities of the RAFT/MADIX agents are investigated by measuring the apparent kinetics and activation energy of the thermal decomposition reactions. Both Z-group and R-group influence the stability of the agents through electronic and steric effects. Lone pair electron donating heteroatoms of Z-group show a remarkable stabilizing effect while electron withdrawing substituents, either in Z- or R-group, tends to destabilize the agent. In addition, bulkier or more β-hydrogens result in faster decomposition rate or lower decomposition temperature. Thus, the stability of the RAFT/MAIDX agents decreases in the order where R is (with identical Z = phenyl) -CH2Ph (5) > -PS (PS-RAFT 15) > -C(Me)HPh (2) > -C(Me)2C(=O)OC2H5 (7) > -C(Me)2Ph(1) > -PMMA (PMMA-RAFT 16) > -C(Me) 2CN (6). For those possessing identical leaving group such as 1-phenylethyl, the stability decreases in the order of O-ethyl (11) > -N(CH2CH3)2 (13) > -SCH(CH3)Ph (8) > -Ph (2) > -CH2Ph (4) > -PhNO2 (3). These results consort with the chain transfer acitivities measured by the CSIRO group and agree well with the ab initio theoretical results by Coote. In addition, the difference between thermal stabilities of the universal RAFT agents at neutral and protonated states has also been demonstrated.
UV laser photodeposition of nanomagnetic soot from gaseous benzene and acetonitrile-benzene mixture
Pola, Josef,Ouchi, Akihiko,Mary?ko,Vorlí?ek,?ubrt, Jan,Bakardjieva,Bastl, Zdeněk
experimental part, p. 188 - 194 (2012/02/02)
Megawatt KrF laser gas-phase photolysis of benzene and acetonitrile-benzene mixture was studied by using mass spectroscopy-gas-chromatography and Fourier transform infrared spectroscopy for analyses of volatile products, and by Fourier transform infrared, Raman and X-ray photoelectron spectroscopy, electron microscopy and magnetization measurements for analyses of solid products deposited from the gas-phase. The results are consistent with carbonization of benzene and decomposition of non-absorbing acetonitrile in carbonizing benzene through collisions with excited benzene and/or its fragments. The solid products from benzene and acetonitrile-benzene mixture have large surface area and are characterized as nanomagnetic amorphous carbonaceous soot containing unsaturated C centers prone to oxidation. The nanosoot from acetonitrile-benzene mixture incorporates CN groups, confirms reactions of benzene fragments with CN radical and has a potential for modification by reactions at the CN bonds.
Looking for heteroaromatic rings and related isomers as interstellar candidates
Lattelais,Ellinger,Matrane,Guillemin
experimental part, p. 4165 - 4171 (2011/08/02)
Finding complex organic molecules in the interstellar medium (ISM) is a major concern for understanding the possible role of interstellar organic chemistry in the synthesis of prebiotic species. The present interdisciplinary report is a prospective study aimed at helping detection of heteroaromatic compounds or at least of some of their isomers in the ISM. The thermodynamic stabilities of the C4H5N, C4H4O, C4H4S families were calculated using density functional theory (DFT). It was found that pyrrole, furan and thiophene are unambiguously the most stable isomers at the 10-50 K temperatures of the ISM. Several of the less stable isomers were synthesized and flash vacuum thermolysis experiments were performed on these species. Although the detection of pyrrole in the pyrolysis of many compounds has been reported in the literature, we observed that none of its isomers led to pyrrole in these conditions, which suggests that other formation routes are to be considered. On the other hand, these three aromatic compounds present a very high stability, few % been decomposed at 1500 K by flash vacuum thermolysis; these experiments also show a great stability of crotonitrile that is the most stable compound that can be formed in these conditions. The rotational constants, dipole moments and IR frequencies of the low-lying isomers are given to encourage laboratory experiments on these prototype molecules.
Synthesis and properties of bis(biphenyl)chromium(i) 1,4-di(2- cyanoisopropyl)-1,4-dihydrofulleride and 1-(2-cyanoisopropyl)-1,2- dihydrofullerene
Markin,Shevelev,Domrachev,Fukin,Baranov,Lopatin,Kuropatov,Kirillov,Shavyrin,Kurskii
body text, p. 1970 - 1974 (2009/12/23)
Radical-ion salts bis(biphenyl)chromium(i) 1,4-di(2-cyanoisopropyl)-1,4- dihydrofulleride [(Ph2)2Cr]+?[1,4- (CMe2CN)2C60]-? and bis(biphenyl)chromium(i) 1-(2-cyanoisopropyl)-1,2-
Catalytic (AMM)oxidation process for conversion of lower alkanes to carboxylic acids and nitriles
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Page/Page column 9, (2008/06/13)
An improved single-step catalytic (amm)oxidation process for the conversion of one or more C3 to C5 alkanes, in the presence of supercritical fluid, to one or more (amm)oxidation products, such as unsaturated carboxylic acids and unsaturated nitriles.
