40912-11-6Relevant academic research and scientific papers
A recyclable CO surrogate in regioselective alkoxycarbonylation of alkenes: Indirect use of carbon dioxide
Gehrtz,Hirschbeck,Fleischer
supporting information, p. 12574 - 12577 (2015/08/06)
Herein, we report a Pd-catalysed alkoxycarbonylation of alkenes based on the use of a recyclable CO2 reduction product, the crystalline and air-stable N-formylsaccharin, as a CO surrogate. The carbonylation proceeds under ambient conditions in an exceptionally complementary regioselective fashion yielding the desired branched products from styrene derivatives and valuable linear esters from alkyl-substituted alkenes.
Ti/Ni-mediated inter- and intramolecular conjugate addition of aryl and alkenyl halides and triflates
Marquez, Irene R.,Miguel, Delia,Millan, Alba,Marcos, M. Luisa,De Cienfuegos, Luis Alvarez,Campana, Araceli G.,Cuerva, Juan M.
, p. 1529 - 1541 (2014/03/21)
In this work, we show that the unique combination of a nickel catalyst and Cp2TiCl allows the direct conjugate addition of aryl and alkenyl iodides, bromides, and to a lesser extent, chlorides and triflates to α,β-unsaturated carbonyls at room temperature, without requiring the previous formation of an organometallic nucleophile. The reaction proceeds inter- and intramolecularly with good functional group compatibility, which is key for the development of free protecting group methodologies. Carbo- and heterocycles of five- and six-membered rings are obtained in good yields. Moreover, some insights about the mechanism involved have been obtained from cyclic voltammetry, UV-vis, and HRTEM measurements.
Paracyclophanes: Extending the bridges. Synthesis
Pechlivanidis, Zissis,Hopf, Henning,Ernst, Ludger
experimental part, p. 223 - 237 (2009/06/21)
Preparatively satisfactory routes to [3.2]paracyclophane (10), [4.2]paracyclophane (14), [4.3]paracyclophane (19) as well as several derivatives of these compounds - among others the bromides 25, the ester 31, the diesters 40-43 - are described using well-established methods of cyclophane chemistry (ring-closure reactions leading to thiacyclophanes, ring contraction by sulfone pyrolysis). The parent systems and their derivatives are now available in gram quantities allowing a study of their chemical properties. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
Heterogeneous palladium multi-task catalyst for sequential Heck-reduction-cyclization (HRC) reactions: influence of the support
Ibarguren, Oier,Zakri, Cécile,Fouquet, Eric,Felpin, Fran?ois-Xavier
supporting information; experimental part, p. 5071 - 5074 (2009/12/01)
An evaluation study of various palladium supports led to the selection of charcoal as the most efficient system for the preparation of oxindoles by sequential Heck-reduction-cyclization (HRC) reactions. The in situ prepared Pd0/C was not recyclable for further cross-coupling reactions but remains still highly active for reduction processes. The sustainable chemistry described herein allows extremely simple experimental protocol under mild conditions, free of any base, ligand and additive.
Preparation of 2-Quinolones by sequential heck reduction-cyclization (HRC) reactions by using a multitask palladium catalyst
Felpin, Francois-Xavier,Coste, Jerome,Zakri, Cecile,Fouquet, Eric
experimental part, p. 7238 - 7245 (2010/03/25)
One-pot sequential Heck reduction-cyclization (HRC) reactions leading to the synthesis of substituted 2-quinolones have been developed by using a heterogeneous or mixed homogeneous/heterogeneous multitask palladium catalyst with charcoal as a support. The whole sequence occurs under very mild conditions without the need for additives (ligand or base) by taking advantage of the high reactivity of aryldiazonium salts as "super electrophiles". Recycling experiments showed that the reused heterogeneous Pd°/C catalyst was not able to promote another HRC sequence but was, however, still highly active for hydrogenation, hydrodehalogenation, as well as hydrogenolysis reactions.
CoBr2(Bpy): An efficient catalyst for the direct conjugate addition of aryl halides or triflates onto activated olefins
Amatore, Muriel,Gosmini, Corinne,Perichon, Jacques
, p. 6130 - 6134 (2007/10/03)
An efficient cobalt-catalyzed method devoted to the direct conjugate addition of functionalized aryl compounds onto Michael acceptors is described. The CoBr2(2,2′-bipyridine) complex appears to be an extremely suitable catalyst for the activation of a variety of aromatic reagents ranging from halides to triflates functionalized by reactive groups. This procedure allows for the synthesis of compounds resulting from 1,4-addition in good to excellent yields. The versatility of this original process represents a simple alternative to most known methods using organometallic reagents.
Addition of electrochemically prepared arylzinc species onto activated olefins via a cobalt catalysis
Gomes, Paulo,Gosmini, Corinne,Périchon, Jacques
, p. 1673 - 1676 (2007/10/03)
The consumable anode process allows the electrochemical preparation of arylzinc compounds in the presence of cobalt chloride as catalyst in a mixed solvent acetonitrile/pyridine (9:1). Conjugate addition of these organometallic reagents to olefins is also obtained in good yields via a new method using CoBr2(2,2′-bipyridine)2 as catalyst.
Condensation of organic bromides with vinyl compounds catalysed by nickel complexes in the presence of zinc
Lebedev, S. A.,Lopatina, V. S.,Petrov, E. S.,Beletskaya, I. P.
, p. 253 - 260 (2007/10/02)
The catalytic system (Ph3P)2NiCl2/zinc/pyridine in acetonitrile is an effective catalyst for reactions of aryl and alkyl bromides with styrene and methyl acrylate.With styrene, the reaction yields vinyl hydrogen replacement (condensation) products, viz. stilbenes and β-alkylstyrenes.Methyl acrylate reacts to give conjugated addition (hydrocondensation) products, methyl esters of β-aryl and β-alkyl propionic acids.
CARBOMETHOXYETHYLATION OF ARYL AND ALKYL BROMIDES CATALYZED BY NICKEL COMPLEXES
Lebedev, S. A.,Lopatina, V. S.,Berestova, S. S.,Petrov, E. S.,Beletskaya, I. P.
, p. 1238 - 1241 (2007/10/02)
The reaction of aryl and alkyl bromides with methyl acrylate in the presence of water, pyridine, and a nickel catalyst results in the formation of saturated conjugate-addition products, viz. methyl esters of aryl- and alkylpropionic acids.
Redox-photosensitised Reactions. Part 12. Effects of Magnesium(II) Ion on the 2+ -Photomediated Reduction of Olefins by 1-Benzyl-1,4-dihydronicotinamide: Metal-ion Catalysis of Electron Transfer Processes Involving an NADH Model
Ishitani, Osamu,Ihama, Mikio,Miyauchi, Yoji,Pac, Chyongjin
, p. 1527 - 1532 (2007/10/02)
Magnesium(II) ion catalyses the photosensitised reduction of carbon-carbon double bonds of dimethylfumarate, derivates of methyl cinnamate, and some other related olefins by 1-benzyl-1.4-dihydronicotinamide (BNAH), which proceeds via sequential two electron transfer initiated by the photoexcitation of +2 (bpy = 2,2'-bipyridine).The metal ion forms a complex with BNAH in methanol as well as in 10:1 (v/v) pyridine-methanol, leading to the retardation of electron transfer from BNAH to luminescent excited-state Ru(ppy)32+.The net metal-ion effects arise from the catalysis of both the first and second one-electron reduction processes.
