16633-44-6Relevant academic research and scientific papers
The synergistic effect of copper chromite spinel nanoparticles (CuCr2O4) and basic ionic liquid on the synthesis of cyclopropanecarboxylic acids
Ghasemi, Mohammad Hadi,Kowsari, Elaheh
, p. 7963 - 7975 (2016/11/25)
Abstract: An efficient synthesis of cyclopropanecarboxylic acids using copper chromite spinel nanoparticles and basic ionic liquid is described. In this study, a relatively simple method starting with trans-cinnamic acid for the synthesis of (±)-trans-2-phenylcyclopropanecarboxylic acid, a key intermediate in the synthesis of tranylcypromine sulfate as an active pharmaceutical ingredient, was employed. Using a combination of basic ionic liquid [Bmim]OH and copper chromite spinel nanoparticles as a catalytic system, the best results were obtained in THF as a polar solvent. This method is a useful alternative to other approaches described in the literature. The use of commercially available chemicals, decreased environmental hazards, with no need for the separation of stereoisomers, and consequently a reduced number of overall steps, are the advantages of this approach that make it an appropriate choice at an increased scale. Graphical Abstract: [Figure not available: see fulltext.]
Oxidative ring-opening of ferrocenylcyclopropylamines to N-ferrocenylmethyl β-hydroxyamides
Gee, Yi Sing,Goertz, Neils J. M.,Gardiner, Michael G.,Hyland, Christopher J. T.
supporting information, p. 2498 - 2503 (2016/03/01)
The in situ reduction of ferrocenyl cyclopropylimines to the corresponding amines triggers a facile oxidative ring-opening to yield the formal four-electron oxidation products: N-ferrocenylmethyl β-hydroxyamides. This process is believed to proceed via generation of a ferrocinium ion in the presence of air, leading to facile formation of a distonic radical cation that is ultimately trapped by oxygen.
Silver-promoted, palladium-catalyzed direct arylation of cyclopropanes: Facile access to spiro 3,3′-cyclopropyl oxindoles
Ladd, Carolyn L.,Sustac Roman, Daniela,Charette, André B.
supporting information, p. 1350 - 1353 (2013/05/09)
The Pd-catalyzed, Ag(I)-mediated intramolecular direct arylation of cyclopropane C-H bonds is described. Various spiro 3,3′-cyclopropyl oxindoles can be obtained in good to excellent yields from easily accessible 2-bromoanilides. The kinetic isotope effect was determined and epimerization studies were conducted, suggesting that the formation of a putative Pd-enolate is not operative and that the reaction proceeds via a C-H arylation pathway.
The first cyclopropanation reaction of unmasked α,β-unsaturated carboxylic acids: Direct and complete stereospecific synthesis of cyclopropanecarboxylic acids promoted by Sm/CHl3
Concellon, Jose M.,Rodriguez-Solla, Humberto,Simal, Carmen
, p. 2685 - 2688 (2008/02/08)
Equation Presented A samarium-promoted cyclopropanation of unmasked α,β-unsaturated acids is described. This reaction can be carried out on (E)- or (Z)α,β-unsaturated carboxylic acids. In all cases the process is completely stereospecific and stereoselective. A mechanism has been proposed to explain the cyclopropanation reaction.
Exploring distal regions of the A3 adenosine receptor binding site: Sterically constrained N6-(2-phenylethyl)adenosine derivatives as potent ligands
Tchilibon, Susanna,Kim, Soo-Kyung,Gao, Zhan-Guo,Harris, Brian A.,Blaustein, Joshua B.,Gross, Ariel S.,Duong, Heng T.,Melman, Neli,Jacobson, Kenneth A.
, p. 2021 - 2034 (2007/10/03)
We synthesized phenyl ring-substituted analogues of N6-(1S,2R)- (2-phenyl-1-cyclopropyl)adenosine, which is highly potent in binding to the human A3AR with a Ki value of 0.63nM. The effects of these structural changes on affinity at human and rat adenosine receptors and on intrinsic efficacy at the hA3AR were measured. A 3-nitrophenyl analogue was resolved chromatographically into pure diastereomers, which displayed 10-fold stereoselectivity in A3AR binding in favor of the 1S,2R isomer. A molecular model defined a hydrophobic region (Phe168) in the putative A3AR binding site around the phenyl moiety. A heteroaromatic group (3-thienyl) could substitute for the phenyl moiety with retention of high affinity of A3AR binding. Other related N6-substituted adenosine derivatives were included for comparison. Although the N 6-(2-phenyl-1-cyclopropyl) derivatives were full A3AR agonists, several other derivatives had greatly reduced efficacy. N 6-Cyclopropyladenosine was an A3AR antagonist, and adding either one or two phenyl rings at the 2-position of the cyclopropyl moiety restored efficacy. N6-(2,2-Diphenylethyl)adenosine was an A 3AR antagonist, and either adding a bond between the two phenyl rings (N6-9-fluorenylmethyl) or shortening the ethyl moiety (N 6-diphenylmethyl) restored efficacy. A QSAR study of the N 6 region provided a model that was complementary to the putative A3AR binding site in a rhodopsin-based homology model. Thus, a new series of high-affinity A3AR agonists and related nucleoside antagonists was explored through both empirical and theoretical approaches.
A novel approach to enantiopure cyclopropane compounds from biotransformation of nitriles
Wang, Mei-Xiang,Feng, Guo-Qiang
, p. 1575 - 1583 (2007/10/03)
Rhodococcus sp. AJ270, a powerful and versatile nitrile hydratase/amidase containing microbial whole-cell system, catalyzed the enantioselective hydrolysis of both racemic trans- and cis-2-arylcyclopropanecarbonitriles to afford the corresponding amides and acids with enantiomeric excesses as high as >99%. The reaction rate and enantioselectivity observed for both nitrile hydratase and amidase were also strongly dependent upon the nature of the substituent and substitution pattern on the benzene ring of the substrates. The application of and the advantages of biotransformation of nitriles were demonstrated by preparing (1S,2R)-2-phenylcyclopropylamine and (1R,2R)-2-phenylcyclopropylmethylamine through facile and straightforward chemical manipulations of (1S,2S)-2-phenylcyclopropanecarboxylic acid and (1R,2R)-2-phenylcyclopropanecarboxamide, respectively.
Picosecond radical kinetics. Rate constants for ring openings of 2-aryl-substituted cyclopropylcarbinyl radicals
Newcomb,Choi,Toy
, p. 1123 - 1135 (2007/10/03)
The kinetics of ring openings of a series of eight (trans-2-arylcyclopropyl)methyl radicals (1) were studied by indirect kinetic methods using Barton's PTOC esters as radical precursors and reaction with PhSeH as the competition reaction. The substituents were CF3, F, Me, and OMe located on both the para and meta positions of the aromatic ring. Syntheses of the radical precursors and the products of the radical reactions are described. Kinetics were determined between -43 and 25°C in four cases (CF3 and OMe substituents) and at 0 and 25°C in the other four cases. The rate constants at 25°C ranged from 1.0 x 1011 s-1 (p-CH3) to 4.1 x 1011 s-1 (p-CF3). The relatively large acceleration of the p-CF3 group, ca. 2.5 times as fast as the parent system with Ar = Ph, correlates well with Adam's ΔD substituent parameters but not with other radical substituent parameters. These calibrated radical rearrangements provide a new set of ultrafast reactions that can be applied in mechanistic probe studies.
