72229-07-3Relevant academic research and scientific papers
Stereoselective cyclopropanation under solvent free conditions: Catalyzed by a green and efficient recyclable Cu-exchanged bentonite
Bendeddouche, Choukry K.,Adjdir, Mehdi,Benhaoua, Hadj
, p. 217 - 223 (2016/03/01)
Background: The cyclopropanation reaction was inspected by addition of carbene generated from ethyl diazoacetate in the presence of a greener Cu-exchanged bentonite catalyst to olefin under solvent free condition. The cyclopropanes were obtained with good yields. Our own contribution in this area was to introduce a modified Algerian bentonite as a catalyst and microwave activation as a mode of heating. Methods: A catalytic material developed from natural type montmorillonite clays, from deposits of Maghnia (Western Algeria), by cation exchange (Cu2+) was characterized by different spectral methods. The catalytic properties of the new material were explored in cyclopropanation reaction of olefins under microwave irradiation. A comparative study with Cu-exchanged bentonite as catalyst between microwave activation and classical heating was conducted. Results: Cu2+ exchanged clay is an efficient catalyst in the generation of carbenes from diazocompounds, under microwave irradiation. The formation of carboxylate cyclopropane was performed in solvent free condition with moderate diastereoselectivity. The yields were good, and the catalyst can be reused at least three times without noticeable loss of catalytic activity. Conclusion: This work shows that the coupling "modified clay/microwave activation" is a clean and simple access to functionalized cyclopropanes. This reusable Cu exchanged clay material is shown to be as a good substitute for many sophisticated and hardly accessible catalysts.
Copper(I)-homoscorpionate catalysts for the preferential, kinetically controlled cis cyclopropanation of α-olefins with ethyl diazoacetate
Diaz-Requejo, M. Mar,Caballero, Ana,Belderrain, Tomas R.,Nicasio, M. Carmen,Trofimenko, Swiatoslaw,Perez, Pedro J.
, p. 978 - 983 (2007/10/03)
In situ prepared copper catalysts TpxCu (Tpx = homoscorpionate) catalyze the olefin cyclopropanation reaction using ethyl diazoacetate as the carbene source. Very high values of both activity and diastereoselectivity toward the cis isomer have been obtained for styrene, α-methylstyrene, 1-hexene, 1-octene, vinyl acetate, n-butyl vinyl ether, 2,5-dimethyl-2,4-hexadiene, and 3,3-dimethyl-1-butene. The effect of the temperature in the diastereoselectivity was almost negligible within the range -10 to +30°C. Kinetic studies have allowed us to propose that the homoscorpionate ligand might act in a dihapto form during the catalytic process. This transformation seems to operate under kinetic control, where the formation of the cis isomer would govern the reaction rate.
Reactivity of ethyldiazoacetate towards alkenes under microwave irradiation
Bendeddouche, Kamel C.,Rechsteiner, Benno,Texier-Boullet, Francoise,Hamelin, Jack,Benhaoua, Hadj
, p. 114 - 117 (2007/10/03)
Ethyldiazoacetate reacts with alkenes as 1,3 -dipole or as carbene precursor according to the reaction conditions. Comparison with literature reports shows that microwave irradiation can accelerate the process and even enhance the yields in some cases.
Enantioselectivity and cis/trans-Selectivity in Dirhodium(II)-Catalyzed Addition of Diazoacetates to Olefins
Mueller, Paul,Baud, Corine,Ene, Doina,Motallebi, Sharokh,Doyle, Michael P.,et al.
, p. 459 - 470 (2007/10/02)
The RhII-catalyzed carbenoid addition of diazoacetates to olefins was investigated with 4> (1; phox = tetrakis), 4> (2; mepy = tetrakismethyl (2S)-tetrahydro-5-oxopyrrole-2-ca
Olefin cyclopropanation reactions catalysed by novel ruthenacarborane clusters
Demonceau,Saive,De Froidmont,Noels,Hubert,Chizhevsky,Lobanova,Bregadze
, p. 2009 - 2012 (2007/10/02)
Novel ruthenacarborane clusters exhibit high activity as cyclopropanation catalysts in reactions between ethyl diazoacetate and alkenes.
Transition-Metal-Catalyzed Reactions of Diazo Compounds. 1. Cyclopropanation of Double Bonds
Anciaux, Andre J.,Hubert, Andre J.,Noels, Alfred F.,Petiniot, N.,Teyssie, Philippe
, p. 695 - 702 (2007/10/02)
Rhodium(II) and palladium(II) carboxylates are efficient catalysts for the cyclopropanation of olefins by diazo esters.Intramolecular competitions within diolefins and intermolecular competitions between pairs of monoolefins showed quite different cyclopr
