4192-77-2Relevant articles and documents
Heterogenization of (η5-C5Me5) Ru(PPh3)2Cl and its catalytic application for cyclopropanation of styrene using ethyl diazoacetate
Sakthivel, Ayyamperumal,Pedro, Filipe E.,Chiang, Anthony S. T.,Kuehn, Fritz E.
, p. 1682 - 1688 (2006)
(η5-C5Me5)Ru(PPh3) 2Cl (1) is heterogenized on the surface of mesoporous molecular sieves by direct grafting on mesoporous aluminosilicates or by reaction of an aminosilane-linker-modified silicate surface with the chloride ligand. Elemental analyses reveal that the grafted samples contain 0.2-1.8 wt% Ru. The retaining of long-range ordering of mesoporous MCM-41 and MCM-48 after grafting is evidenced from XRD, N2 adsorption-desorption and TEM analysis. FT-IR, TG-MS, 29Si and 1H CP MAS-NMR spectra confirm the successful grafting of complex 1 on the surface of these mesoporous materials. Mesoporous materials grafted with complex 1 are found to be promising catalysts for the cyclopropanation of styrene with ethyl diazoacetate. Georg Thieme Verlag Stuttgart.
Catalytic cyclopropanation of olefins using copper(I) diphosphinoamines
Ahuja, Ritu,Samuelson, Ashoka G.
, p. 1153 - 1160 (2009)
Catalytic cyclopropanation reactions of olefins with ethyl diazoacetate were carried out using copper(I) diphosphinoamine (PPh2)2N(R) (R = iPr, H, Ph and -CH2-C6H4-CH{double bond, long}CHs
Practical preparation method of polymer-incarcerated (PI) palladium catalysts using Pd(II) salts
Hagio, Hiroyuki,Sugiura, Masaharu,Kobayashi, Shu
, p. 375 - 378 (2006)
Polymer-incarcerated (PI) palladium catalyst was practically prepared from inexpensive Pd(II) salts and a polystyrene-based copolymer under reducing conditions. Remarkable effects of alkali metal salts on the palladium loading were observed. PI Pd thus prepared showed high catalytic activity in Mizoroki-Heck reactions and Suzuki-Miyaura couplings with a range of substrates including an aryl chloride. In all cases, the Pd catalyst was recovered quantitatively without leaching, and reused several times without significant loss of activity.
NC-palladacycles as highly effective cheap precursors for the phosphine-free Heck reactions
Beletskaya, Irina P.,Kashin, Alexander N.,Karlstedt, Natalia B.,Mitin, Anton V.,Cheprakov, Andrei V.,Kazankov, Grigoriy M.
, p. 89 - 96 (2001)
Eight cyclopalladated complexes of the formula [Pd2(μ-L)2(N-C)2] (L=OAc, Cl; N-C=cyclometalled N donor: o-(2-pyridyl)phenyl, o-(2-pyridyloxy)phenyl, o-(2-pyridylmethyl)phenyl, o-(N,N-dimethylaminomethyl)phenyl, 8-quinolylmethyl and others) and a six-membered palladacycle with OC coordination (ligand related to 2-acetoamido-4-nitrophenyl), are highly efficient catalysts for the Heck arylation of olefins (styrene, ethyl acrylate) by aryl halides (iodobenzene, bromobenzene, 4-bromoacetophenone). These catalysts are air stable, easy to obtain from a vast number of readily available nitrogen containing molecules, are generally much cheaper than phosphine-ligated palladacycles, but as or more efficient than the latter. Turnover numbers (ton) of up to 4 100 000 and turnover frequencies (tof) up to 530 000 are achieved in the reaction of iodobenzene with ethyl acrylate. Bromobenzene undergoes the Heck reaction (ton=400-700; tof=5-30) in the presence of the promoter additive Bu4NBr. The palladacycles are likely to operate in a common phosphine-free Pd(0)/Pd(II) catalytic cycle, while the differences between various types of palladacycle precursors are accounted for by the kinetics of the catalyst preactivation step.
Improved cross-metathesis of acrylate esters catalyzed by 2nd generation ruthenium carbene complexes
Forman, Grant S.,Tooze, Robert P.
, p. 5863 - 5866 (2005)
The performance of cross-metathesis reactions between acrylate esters and olefins catalyzed by Grubbs catalysts have been enhanced by the simple addition of p-cresol. For example, the efficiency of the cross metathesis reaction between methyl acrylate and
Surface-active ionic liquids for palladium-catalysed cross coupling in water: Effect of ionic liquid concentration on the catalytically active species
Taskin, Meltem,Cognigni, Alice,Zirbs, Ronald,Reimhult, Erik,Bica, Katharina
, p. 41144 - 41151 (2017)
We report the design and synthesis of surface-active ionic liquids for application in palladium-catalyzed cross coupling reactions. A series of dodecylimidazolium-based ionic liquids were applied as additives in the Heck reaction of ethyl acrylate and iodobenzene, and high yields of >90% could be obtained in water without the addition of further ligands. Our results indicate that the ionic liquid concentration in water is the key factor affecting the formation of the catalytically active species and hence the yield. Moreover, imidazolium-based ionic liquids that are able to form a carbene species differ significantly from conventional cationic surfactants, as a concentration dependent formation of the N-heterocyclic carbene complex was observed.
Photoinduced electron transfer reactions of cyclopropanone acetal with conjugated enones in the presence of a redox-type photosensitizer
Abe, Manabu,Nojima, Masatomo,Oku, Akira
, p. 1833 - 1836 (1996)
Photoreactions of the cyclopropanone acetal 1 with conjugated enones 2 in the presence of phenanthrene or pyrene as a redox-type photosensitizer gave the corresponding cross-coupling product 3 or mixtures of 3 with 5 in good yields together with the β-carbonyl radical-dimer 4.
Intermolecular phosphine-free Heck reactions: Amino alcohols as effective ligands
Zawisza, Anna Maria,Muzart, Jacques
, p. 1015 - 1017 (2011)
Intermolecular phosphine-free Heck reactions occur in high yields, under basic conditions, using a catalytic mixture of Pd(OAc)2 and a β-amino alcohol. It is assumed that the active catalytic species are N-liganded Pd0 species. The r
Zinc reduction of alkynes
Kaufman, Don,Johnson, Erin,Mosher, Michael D.
, p. 5613 - 5615 (2005)
The dissolving zinc metal reduction of ethyl phenylpropiolate to the corresponding cinnamate ester can be stereochemically controlled by changing the proton source in the reaction. The results of this study, while not fully understood, may imply that surf
A convenient and chemoselective one-pot oxidation/Wittig reaction for the C2-homologation of carbohydrate-derived glycols
Crisostomo, Fernando R. Pinacho,Carrillo, Romen,Martin, Tomas,Garcia-Tellado, Fernando,Martin, Victor S.
, p. 10099 - 10101 (2005)
A simple and convenient one-pot protocol for the chemoselective C 2-homologation of carbohydrate-derived glycols is described. The method comprises the chemoselective oxidation of the glycol to the corresponding hydroxyaldehyde and the subsequent Wittig alkenylation. In addition, the method does not need selective protective group manipulation, and it is safe, economical, fast (5 to 6 h), and bench-friendly. Its general utility is discussed.
