1070-27-5Relevant academic research and scientific papers
The evolution of reactive ligands in the catalysis of radical processes by copper complexes
Tarkhanova,Gantman,Rostovschikova
, p. 88 - 100 (2012)
Two radical reactions (addition of CCl4 to the double bond of oct-1-ene and oxidation of dodecane-1-thiol with air oxygen) catalyzed by copper complexes have been investigated. Various nitrogen-containing compounds (aliphatic and aromatic amines, aminoalcohols, aminoacids) were used as the ligands. In both cases, products of ligand transformation have been observed, products of the transformations have been identified by GLC-MS. In case of the CCl4 addition, the reaction can be initiated by the either copper complex or the ligand. In case of the thiol coupling, the reaction proceeds as a conjugated oxidation of both the thiol and the ligand. A correlation between the donor ability of the ligand and its reactivity has been found. Copyright Taylor and Francis Group, LLC.
The addition of halogenocarbons to alkenes in the presence of (R = H, Me), and 2CH2>
Davis, Reg,Khazal, Nasser M.S.,Bitterwolf, Thomas E.
, p. 51 - 58 (1990)
The addition of halogenocarbons to alkenes in the presence of (I) has been the subject of a detailed kinetic study.These results, together with the results of cross-over addition reactions of a halogenocarbon mixture and cross-over studies on catalyst mixtures of (I) and (IV) are interpreted in favour of a mechanism involving catalysis by an intact binuclear complex, but which also involves free radical intermediates.Studies on catalysis by (II) additional to those we reported earlier, suggest an analogous mechanism in this case, but also involving CO dissociation from the hexacarbonyl yielding IV as the active catalyst.A preliminary study of catalysis by 2CH2> (III) suggests this complex also follows a similar mechanism.
Atom Transfer Radical Addition Catalyzed by Ruthenium-Arene Complexes Bearing a Hybrid Phosphine-Diene Ligand
Chotard, Florian,Malacea-Kabbara, Raluca,Balan, Cédric,Bodio, Ewen,Picquet, Michel,Richard, Philippe,Ponce-Vargas, Miguel,Fleurat-Lessard, Paul,Le Gendre, Pierre
, p. 812 - 820 (2018)
The synthesis and characterization of a series of arene ruthenium complexes bearing either (3,5-cycloheptadienyl)diphenylphosphine or (cycloheptyl)diphenylphosphine are reported. Upon irradiation or heating, all these complexes lose their arene ligand but then exhibit a different behavior depending on the nature of the phosphine ligand. (Cycloheptadienyl)phosphine complexes 1 and 3 give a cationic dinuclear Ru complex 5 for which the two Ru atoms are bridged by three chlorido ligands and flanked by two tridendate (cycloheptadienyl)phosphines. (Cycloheptyl)diphenylphosphine complexes 2 and 4 undergo arene exchange when toluene is used as solvent or degrade in dichloromethane. ATRA catalytic trials conducted in parallel with these complexes using CCl4 and styrene as standard substrates, highlighted the deep impact of the dienyl moiety on the results. Under smooth conditions (UV irradiation or moderate heating), only (cycloheptyl)phosphine derivatives give Karasch adduct in satisfactory yields. Their performance was considerably improved by combining irradiation and heating. At higher temperature, cationic dinuclear complex 5 was revealed as active and robust, giving turnover numbers as high as 9700 when tetradecene and CCl4 were used as substrates.
Addition of α-polyhalides to olefins under mild reaction conditions, catalyzed by Mo(CO)6
Shvo, Youval,Green, Revital
, p. 77 - 83 (2003)
Mo(CO)6 was found to be an efficient pre-catalyst in the 1,2-addition reaction of α-polyhalides to various olefins. Significantly, the reaction was run under mild conditions, viz. refluxing acetonitrile, with satisfactory yields. Cr(CO)6/
Studies on sulfinatodehalogenation: The addition reaction of halocarbons with olefins initiated by sodium dithionite
Wu,Huang
, p. 59 - 61 (2001)
Halocarbons such as carbon tetrachloride, CCl3Br, CF3CCl3, BrCF2CF2Br, BrCF2CFClBr and CF2Br2, reacted with olefins in the presence of the sulfinatodehalogenation reagent sodium dithionite under mild conditions to give the corresponding adducts. In the case of F113, CFCl2CF2CFCl2 and CF3Cl3, the polyfluoroalkylation product resulted.
The Reaction of Polyhalides with Allylsilanes Catalyzed by Copper(I) Chloride
Mitani, Michiharu,Hujita, Shigenori
, p. 3055 - 3060 (1997)
Allyltrimethylsilane reacted with polyhalogen compounds in the presence of copper species, such as copper(I) chloride, copper(II) chloride or metallic copper, to form polyhalo compounds containing an allyl group. Other allylsilane derivatives than allyltrimethylsilane were also subjected to a reaction with carbon tetrachloride. 3-Chloro- or 3-bromo-3-trimethylsilyl-1-propene gave 4,4,4-trichloro-1-trimethylsilyl-1-butene. Ethyl 1-trimethylsilylallyl carbonate afforded ethyl 4,4,4-trichloro-1-butenyl carbonate along with a hydrotrichloromethylation product. 2-Methyl-3-trimethylsilyl-1-propene yielded a product based on the addition of a trichloromethyl group followed by hydrogen-elimination from a 2-methyl group.
From atom transfer radical addition to atom transfer radical polymerisation of vinyl monomers mediated by ruthenium indenylidene complexes
Opstal, Tom,Verpoort, Francis
, p. 257 - 262 (2003)
Ruthenium indenylidene complexes provide a new class of versatile catalysts for promoting the Atom Transfer Radical Addition (ATRA) of carbon tetrachloride and chloroform toward a whole array of olefins such as acrylates, methacrylates, styrene and 1-octene. The reaction was successfully extended to an Atom Transfer Radical Polymerisation (ATRP) process by changing the monomer/halide ratio. The polymerisation reaction can be accelerated by adding n-Bu2NH to the reaction mixture. However this leads to an uncontrolled polymerisation. Further improvements to the catalytic activity can be made by transforming the Ru complexes in the cationic 14-electron species or exchanging the indenylidene fragment with an ethoxycarbene. A very high activity is reached when these complexes are exposed to methyl methacrylate in aqueous media while maintaining excellent control over the formed polymers.
New and improved catalysts for transition metal catalysed radical reactions
De Campo, Floryan,Lastecoueres, Dominique,Verlhac, Jean-Baptiste
, p. 2117 - 2118 (1998)
New CuI and FeII complexes displayed considerable improvements in atom transfer radical addition reactions.
The addition of halogenocarbons to alkenes in the presence of and related complexes
Davis, Reg,Durrant, Jim L. A.,Khazal, Nasser M. S.,Bitterwolf, Thomas E.
, p. 229 - 239 (1990)
A kinetic study has been made of the addition of halogenocarbons to alkenes in the presence of (I).The results, together with the results of cross-over addition reactions of a halogenocarbon mixture and cross-over studies on catalyst mixtures of I and (II) have been interpreted in terms of a mechanism which involves catalysis by an intact dinuclear species, probably , but which also involves free radical intermediates.
Structural and Electronic Noninnocence of α-Diimine Ligands on Niobium for Reductive C-Cl Bond Activation and Catalytic Radical Addition Reactions
Nishiyama, Haruka,Ikeda, Hideaki,Saito, Teruhiko,Kriegel, Benjamin,Tsurugi, Hayato,Arnold, John,Mashima, Kazushi
, p. 6494 - 6505 (2017)
A d0 niobium(V) complex, NbCl3(α-diimine) (1a), supported by a dianionic redox-active N,N′-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1,3-butadiene (α-diimine) ligand (ene-diamido ligand) served as a catalyst for radical addition reactions of CCl4 to α-olefins and cyclic alkenes, selectively affording 1:1 radical addition products in a regioselective manner. During the catalytic reaction, the α-diimine ligand smoothly released and stored an electron to control the oxidation state of the niobium center by changing between an η4-(σ2,π) coordination mode with a folded MN2C2 metallacycle and a κ2-(N,N′) coordination mode with a planar MN2C2 metallacycle. Kinetic studies of the catalytic reaction elucidated the reaction order in the catalytic cycle: the radical addition reaction rate obeyed first-order kinetics that were dependent on the concentrations of the catalyst, styrene, and CCl4, while a saturation effect was observed at a high CCl4 concentration. In the presence of excess amounts of styrene, styrene coordinated in an η2-olefinic manner to the niobium center to decrease the reaction rate. No observation of oligomers or polymers of styrene and high stereoselectivity for the radical addition reaction of CCl4 to cyclopentene suggested that the C-C bond formation proceeded inside the coordination sphere of niobium, which was in good accordance with the negative entropy value of the radical addition reaction. Furthermore, reaction of 1a with (bromomethyl)cyclopropane confirmed that both the C-Br bond activation and formation proceeded on the α-diimine-coordinated niobium center during transformation of the cyclopropylmethyl radical to a homoallyl radical. With regard to the reaction mechanism, we detected and isolated NbCl4(α-diimine) (6a) as a transient one-electron oxidized species of 1a during reductive cleavage of the C-X bonds; in addition, the monoanionic α-diimine ligand of 6a adopted a monoanionic canonical form with selective one-electron oxidation of the dianionic ene-diamido form of the ligand in 1a.
