771-10-8Relevant 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.
α-fluoro-2,2,3,3-tetramethylcyclopropanecarboxamide, a novel potent anticonvulsant derivative of a cyclic analogue of valproic acid
Pessah, Neta,Bialer, Meir,Wlodarczyk, Bogdan,Finnell, Richard H.,Yagen, Boris
experimental part, p. 2233 - 2242 (2010/02/28)
2,2,3,3-Tetramethylcyclopropanecarboxylic acid (TMCA, 4) is a cyclic analogue of the antiepileptic drug (AED) valproic acid (VPA) (1). α-F, α-Cl, R-Br, and R-methyl derivatives of 4 and their amides were synthesized and tested in rodent models for anticonvulsant potency and AED-induced teratogenicity. In the anticonvulsant rat-maximal electroshock (MES) and subcutaneous metrazol (scMet) tests, α-Cl-TMCD (17) had ED 50 values of 97 and 27 mg/kg, respectively. α-F-TMCD (11) was 120 times more potent than VPA in the rat-scMet test (ED50) 6 mg/kg) and had a protective index (PI) TD50/ED50) of 20. In the 6 Hz psychomotor mouse model 11 had ED50 values of 57 mg/kg (32 mA) and 59 mg/kg (44 mA). The ED50 values of 11 in the hippocampal-kindled rat model and in the pilocarpine-induced-status rat model were 30 and 23 mg/kg, respectively. Unlike 1, 11 was nonteratogenic in mice. This novel compound has the potential to become a candidate for development as a new potent and safe antiepileptic and CNS drug.
ALPHA-HALO- AND ALPHA-ALKYL-CYCLOPROPYLCARBOXY COMPOUNDS AND USES THEREOF
-
Page/Page column 39, (2008/12/08)
Novel Alpha-halo- and Alpha-alkyl-cyclopropylcarboxy compounds, and uses of these and related compounds in the treatment of a variety of neurological diseases and disorders, and particularly epilepsy, are provided.
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.
Experimental and Theoretical Investigations of Ring-Expansion in 1-Methylcyclopropylcarbene
Thamattoor, Dasan M.,Snoonian, John R.,Sulzbach, Horst M.,Hadad, Christopher M.
, p. 5886 - 5895 (2007/10/03)
1-Methylcyclopropylcarbene, generated by photolysis of two isomeric hydrocarbon precursors, undergoes ring-expansion, readily to give 1-methylcyclobutene. Experimentally, intramolecular carbon-hydrogen insertions are not observed. Trapping studies with TME demonstrates the formation of the expected cyclopropane adduct, and via a double-reciprocal analysis, the lifetime of 1-methylcyclopropylcarbene was determined to be 12 ns in 1,1,2-trichlorotrifluoroethane. Computational studies show that the barrier to ring-expansion is significantly smaller in 1-methylcyclopropylcarbene than in cyclopropylcarbene. The origin of the increased rate of ring-expansion is due to stabilization of the positive charge that occurs at the incipient tertiary carbon that is attached to the migrating carbon center. Department of Chemistry and Biochemistry,.
Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides
Zhu, Zuolin,Espenson, James H.
, p. 9901 - 9907 (2007/10/03)
Methylrhenium trioxide (CH3ReO3 or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, α-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of α-phenoxy ethyl acetates. The use of EDA to form α-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and tobenzil; at the same time the epoxide was converted to an olefin. These results provide further support for the proposed intermediate, a cyclic species containing Re, O, and CHCO2Et (or, occasionally, CPhC(O)Ph)in a three-membered ring.
Branched amides of L-aspartyl-D-amino acid dipeptides
-
, (2008/06/13)
Amides of L-aspartyl-D-amino acid dipeptides of the formula STR1 and physiologically acceptable cationic and acid addition salts thereof wherein Ra is CH2 OH or CH2 OCH3 ; R is a branched member selected from the group consisting of fenchyl, diisopropylcarbinyl, d-methyl-t-butylcarbinyl, d-ethyl-t-butylcarbinyl, di-t-butylcarbinyl, 2-methylthio-2,4-dimethylpentan-3-yl, STR2 where at least one of R3, R4, R5, R6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, X is O, S, SO, SO2, C=O or CHOH; m is zero or 1-4, n and p are each zero, 1, 2 or 3 where the sum of n+p is not greater than 3 and the sum of the carbon atoms in R3, R4, R5 and R6 is not greater than six, and when both of R3 and R4 or R5 and R6 are alkyl they are methyl or ethyl, STR3 where one of R7, R8, R9 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms and the sum of the carbon atoms in R7, R8 and R9 is not greater than six, m and q are the same or different and each have the values previously defined for m; STR4 where each of R12 and R13 are methyl or ethyl, or R12 is hydrogen and R13 is alkyl having from one to four carbon atoms, Z is O or NH and t is 1 or 2, STR5 where W is 1-4, R14 and R16 are each alkyl having from one to four carbon atoms, R15 is H, OH, methyl or ethyl and the sum of the carbon atoms in R14, R15 and R16 is not greater than six and when both of R14 and R15 are alkyl they are methyl or ethyl, and STR6 where R17 and R19 are alkyl having from one to four carbon atoms, R18 and R20 are H or alkyl having one to two carbon atoms, A is OH and B is H, OH or CH3 and taken together A and B are STR7 where the sum of the carbon atoms in R17, R18, R19 and R20 is not greater than six and when both of R17 and R18 or R19 and R20 are alkyl they are methyl or ethyl; said amides are potent sweeteners having advantages over the prior art, edible compositions containing them, methods for their use in edible compositions and novel amide intermediates useful in their production.
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
