1708-32-3Relevant articles and documents
Synthesis of sulphur-containing heterocycles by ring closing diene metathesis
Armstrong, Susan K.,Christie, Brett A.
, p. 9373 - 9376 (1996)
We have shown that, surprisingly, the Schrock molybdenum alkylidene catalyst 1 can perform ring closing metathesis reactions on substrates containing a sulphide group, converting diallyl sulphide 5 to 2,5-dihydrothiophene 6 with >99% conversion. By contrast, the ruthenium alkylidene catalyst 2, which is generally more tolerant of functional groups in the substrate, is unreactive towards diallylsulphide. However even the molybdenum catalyst 1 proved unable to catalyse ring closure of tetrathiafulvalene derivative 7.
Efficiency of a ruthenium catalyst in metathesis reactions of sulfur-containing compounds
Spagnol, Gaelle,Heck, Marie-Pierre,Nolan, Steven P.,Mioskowski, Charles
, p. 1767 - 1770 (2002)
1,3-Dimesitylimidazol-2-ylidene ruthenium benzylidene catalyst (RuCl2(=C(H)Ph)(PCy3)(IMes)) has been successfully employed in ring-closing metathesis reactions of acyclic diene sulfides, disulfides, and dithianes and in self-cross metathesis reactions of ene-sulfides, thioethers and thiols.
Highly efficient Ru-pseudohalide catalysts for olefin metathesis
Conrad, Jay C.,Parnas, Henrietta H.,Snelgrove, Jennifer L.,Fogg, Deryn E.
, p. 11882 - 11883 (2005)
Ruthenium alkylidene complexes containing one aryloxide "pseudohalide" ligand catalyze ring-closing metathesis of diene and ene-yne substrates with exceptionally high efficiency. Chromatographic removal of Ru residues is unexpectedly facile, offering a convenient means of isolating pure organic products in high yields. Copyright
Synthesis of Vanadium Oxo Alkylidene Complex and Its Reactivity in Ring-Closing Olefin Metathesis Reactions
Belov, Dmitry S.,Bukhryakov, Konstantin V.,Chakraborty, Indranil,Fenoll, Didac A.,Solans-Monfort, Xavier
supporting information, p. 2939 - 2944 (2021/09/13)
V imido alkylidenes have been applied for the ring-opening metathesis polymerization involving cyclic olefins. However, those complexes found limited application in reactions with acyclic terminal olefins due to instability toward ethylene. Experimental and theoretical studies show that the β-hydride elimination from unsubstituted metallacyclobutene is the primary decomposition pathway in those systems. Herein, we report the synthesis of the first catalytically active V oxo alkylidene, VO(CHSiMe3)(PEt3)2Cl, which exhibits the highest reported productivity with various terminal olefins in ring-closing metathesis reactions among known V catalysts. Presented DFT studies indicate that β-hydride elimination is significantly disfavored for V oxo species.
N-Heterocyclic Carbene Complexes Of Metal Imido Alkylidenes And Metal OXO Alkylidenes, And The Use Of Same
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Paragraph 0181, (2017/03/21)
The invention relates to an N-heterocyclic carbene complex of general formulas I to IV (I) (II) (III) (IV), according to which A1 stands for NR2 or PR2, A2 stands for CR2 R2′, NR2, PR2, 0 or S, A3 stands for N or P, and C stands for a carbene carbon atom, ring B is an unsubstituted or a mono or poly-substituted 5 to 7-membered ring, substituents R2 and R2′ stand, inter alia, for a linear or branched C1-Cw-alkyl group and, if N and N each stand for NR2 or PR2, are the same or different, M in formulas I, II, III or IV stands for Cr, Mo or W, X 1 or X2 in formulas I to IV are the same or different and represent, inter alia, C1-C1s carboxylates and C1-C1s-alkoxides, Y is inter alia oxygen or sulphur, Z is inter alia a linear or branched C1-Cw-alkylenoxy group, and R 1 and R1′ in formulas I to IV are, inter alia, an aliphatic or aromatic group. These compounds are particularly suitable for use as catalysts for olefin metathesis reactions and have the advantage, compared to known Schrock carbene complexes, of displaying clearly increased tolerance to functional groups such as, in particular, aldehydes, secondary amines, nitriles, carboxylic acids and alcohols.
Allyl sulphides in olefin metathesis: Catalyst considerations and traceless promotion of ring-closing metathesis
Edwards, Grant A.,Culp, Phillip A.,Chalker, Justin M.
supporting information, p. 515 - 518 (2015/02/19)
Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions. This journal is
Grubbs-Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids
Koy, Maximilian,Altmann, Hagen J.,Autenrieth, Benjamin,Frey, Wolfgang,Buchmeiser, Michael R.
supporting information, p. 1632 - 1638 (2016/04/10)
The novel dicationic metathesis catalyst [(RuCl2(H2ITapMe2)(=CH-2-(2-PrO)-C6H4))2+(OTf-)2] (Ru-2, H2ITapMe2 = 1,3-bis(2',6'-dimethyl-4'-trimethylammoniumphenyl)-4,5-dihydroimidazol-2-ylidene, OTf- = CF3SO3-) based on a dicationic N-heterocyclic carbene (NHC) ligand was prepared. The reactivity was tested in ring opening metathesis polymerization (ROMP) under biphasic conditions using a nonpolar organic solvent (toluene) and the ionic liquid (IL) 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [BDMIM+][BF4-]. The structure of Ru-2 was confirmed by single crystal X-ray analysis.
Mechanism of formation of sulphur aroma compounds from l-ascorbic acid and l-cysteine during the Maillard reaction
Yu, Ai-Nong,Tan, Zhi-Wei,Wang, Fa-Song
experimental part, p. 1316 - 1323 (2012/06/30)
The sulphur aroma compounds produced from a phosphate-buffered solution (pH 8) of l-cysteine and l-, l-[1-13C] or l-[4-13C] ascorbic acid, heated at 140 ± 2 °C for 2 h, were examined by headspace SPME in combination with GC-MS. MS data indicated that C-1 of l-ascorbic acid was not involved in the formation of sulphur aroma compounds. The sulphur aroma compounds formed by reaction of l-ascorbic acid with l-cysteine mainly contained thiophenes, thiazoles and sulphur-containing alicyclic compounds. Among these compounds, 1-butanethiol, diethyl disulphide, 5-ethyl-2-methylthiazole, cis and trans-3,5-dimethyl-1,2,4-trithiolane, thieno[2,3-b]thiophene, thieno[3,2-b]thiophene, cis and trans-3,5-diethyl-1,2,4-trithiolane, 1,2,5,6-tetrathiocane, 2-ethylthieno[2,3-b]thiophene, 2,4,6-trimethyl-1,3,5- trithiane and cyclic octaatomic sulphur (S8) were formed solely by l-cysteine degradation, and the rest by reaction of l-ascorbic acid degradation products, such as hydroxybutanedione, butanedione, acetaldehyde, acetol, pyruvaldehyde and formaldehyde with l-cysteine or its degradation products, such as H2S and NH3. A new reaction pathway from l-ascorbic acid via its degradation products was proposed.
Sequential reactions with Grubbs catalyst and ad-mix-α//βusing pdms thimbles
Mwangi, Martin T.,Schulz, Michael D.,Bowden, Ned B.
supporting information; experimental part, p. 33 - 36 (2009/08/08)
Incompatible Grubbs catalyst and an osmium dihydroxylation catalyst were site-isolated from each other using polydimethylsiloxane thimbles. The Grubbs catalyst was added to the interior of the thimbles, and AD-mix-α//β was added to the exterior. Organic substrates readily fluxed through the walls of the thimbles and reacted with each catalyst. A series of cascade reactions were developed including those with intermediates possessing low boiling points or that were foul smelling.
Olefin ring closing metathesis and hydrosilylation reaction in aqueous medium by grubbs second generation ruthenium catalyst
Polshettiwar, Vivek,Varma, Rajender S.
supporting information; experimental part, p. 7417 - 7419 (2009/05/07)
(Chemical Equation Presented) The Grubbs second generation ruthenium catalyst was shown to catalyze various olefin ring closing metathesis and hydrosilylation reactions in aqueous medium. Reactions proceeded in pure water without any additives or cosolvents, in a short period of time. We found that inhomogeneity of the reaction mixture does not prevent high conversion (70-95%) of the products in both reactions.
