244092-75-9Relevant academic research and scientific papers
Enantioseparation, in vitro testing, and structural characterization of triple-binding reactivators of organophosphate-inhibited cholinesterases
?inko, Goran,Brazzolotto, Xavier,Kne?evic, Anamarija,Kovarik, Zrinka,Marakovic, Nikola,Roncěvic, Igor
, p. 2771 - 2790 (2020/09/01)
The enantiomers of racemic 2-hydroxyimino-N-(azidophenylpropyl)acetamide-derived triple-binding oxime reactivators were separated, and tested for inhibition and reactivation of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibited with ta
Determination of the Absolute Configuration of (S)-N-(1-Aryl-allyl)-3,5-dinitrobenzamides and Their Elution Order on Brush-Type Chiral Stationary Phases
Kne?evi?, Anamarija,Novak, Jurica,Pescitelli, Gennaro,Vinkovi?, Vladimir
, p. 3982 - 3991 (2018/08/07)
A series of ten enantiomerically pure (S)-N-(1-aryl-allyl)-3,5-dinitrobenzamides (S-DNBs) was prepared using enzymatic resolution and chiral chromatography. Enzymatic resolution of corresponding 1-aryl-allylamines using Candida antarctica lipase B (CaLB) was efficient for amines with no steric hindrance near the stereogenic center and S-DNB amides were prepared by acylation of the obtained S-amine. When steric effects interrupted enzymatic resolution, racemic DNB amides were resolved using a brush-type chiral column (CSP-A) developed in our laboratory. Previously reported behavior of CaLB in kinetic resolution of amines was considered a starting point for the determination of absolute configuration (AC). The AC of prepared S-DNB amides was anticipated using the elution order of prepared DNB amides on CSP-A and commercial Whelk-O1 columns and comparison with DNB amides obtained after acylation of (S)-amines. The comparison between experimental electronic circular dichroism (ECD) spectra with those obtained by conformational analysis and ECD calculations of representative compounds allowed us to verify the AC of prepared DNB amides.
Rhodium-Catalyzed Regiodivergent Hydrothiolation of Allyl Amines and Imines
Kennemur, Jennifer L.,Kortman, Gregory D.,Hull, Kami L.
supporting information, p. 11914 - 11919 (2016/10/06)
The regiodivergent Rh-catalyzed hydrothiolation of allyl amines and imines is presented. Bidentate phosphine ligands with larger natural bite angles (βn ≥ 99°), for example, DPEphos, dpph, or L1, promote a Markovnikov-selective hydrothiolation in up to 88% yield and >20:1 regioselectivity. Conversely, when smaller bite angle ligands (βn ≤ 86°), for example, dppbz or dppp, are employed, the anti-Markovnikov product is formed in up to 74% yield and >20:1 regioselectivity. Initial mechanistic investigations are performed and are consistent with an oxidative addition/olefin insertion/reductive elimination mechanism for each regioisomeric pathway. We hypothesize that the change in regioselectivity is an effect of diverging coordination spheres to favor either Rh-S or Rh-H insertion to form the branched or linear isomer, respectively.
Direct, enantioselective iridium-catalyzed allylic amination of racemic allylic alcohols
Lafrance, Marc,Roggen, Markus,Carreira, Erick M.
supporting information; experimental part, p. 3470 - 3473 (2012/06/01)
The direct route: Iridium-catalyzed direct conversion of branched allylic alcohols into enantioenriched branched primary allylic amines is highly regio- and enantioselective (see scheme; coe=cyclooctene). Copyright
An efficient enzymatic approach to (S)-1-aryl-allylamines
Knezevic, Anamarija,Landek, Goran,Dokli, Irena,Vinkovic, Vladimir
, p. 936 - 941 (2011/09/20)
A range of 1-aryl-allylamines were prepared in moderate to excellent enantioselectivity (ee 63.5%→99.9%) using lipase B from a Candida antarctica catalyzed resolution of racemic amines. This is the first time that CaLB has been used for the resolution of 1-aryl-allylamines. Racemic amines were prepared starting from aromatic aldehydes with a [3,3]-sigmatropic rearrangement of the acyclic imidates as the key step followed by trichloroacetamidate hydrolysis. Aldehydes were converted into acrylic esters using Knoevenagel reaction. After reduction, the corresponding alcohols were used for the preparation of trichloroacetimidates, which were then used in an Overman rearrangement.
Stereospecific substitution of allylic alcohols to give optically active primary allylic amines: Unique reactivity of a (P,alkene)Ir complex modulated by iodide
Roggen, Markus,Carreira, Erick M.
supporting information; experimental part, p. 11917 - 11919 (2010/11/04)
A stereospecific allylic amination of unactivated secondary (2°)-allylic alcohols is reported. The primary (1°)-allylic amine can be isolated directly or protected in situ. Spectroscopic studies have shed light on the structure of the catalytically active Ir?(P,olefin)2I complex.
NEW CHIRAL STATIONARY PHASES FOR CHROMATOGRAPHY BASED ON AROMATIC ALLYL AMINES
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Page/Page column 8; Figure 1, (2009/10/22)
New chiral stationary phases (CSPs) based on chiral selectors covalently bound on a solid support were prepared. Chiral selectors were obtained from enantiomerically pure aromatic amines and 3,5-dinitrobenzoic acid and then linked to the support surface through the allylic double bond. Such obtained materials allow enantioseparation of racemates or enantiomerically enriched compounds. These chiral stationary phases can be used as fillings in chromatographic columns for enantiomer separation of naproxen type drugs and other similar non-steroidal anti-inflammatory drugs (NSAID) by means of high performance liquid chromatography on both the analytical and preparative scale.
Salt-free iridium-catalyzed asymmetric allylic animations with N,N-diacylamines and ortho-nosylamide as ammonia equivalents
Weihofen, Robert,Tverskoy, Olena,Helmchen, Guenter
, p. 5546 - 5549 (2007/10/03)
(Chemical Equation Presented) New variants of the iridium-catalyzed allylic substitution allow N-protected and non-protected chiral allylamines to be prepared with high enantio- and regio-selectivity. The allylamines are used as nucleophiles in highly dia
Enantioselective synthesis of primary 1-(aryl)alkylamines by nucleophilic 1,2-addition of organolithium reagents to hydroxyoxime ethers and application to asymmetric synthesis of G-protein-coupled receptor ligands
Atobe, Masakazu,Yamazaki, Naoki,Kibayashi, Chihiro
, p. 5595 - 5607 (2007/10/03)
(E)-Arylaldehyde oxime ethers bearing a (1S)-2-hydroxy-1-phenylethyl or (2R)-1-hydroxy-2-phenylethyl group as a chiral auxiliary, both derived from a single precursor, methyl (R)-mandelate, underwent nucleophilic addition with organolithium reagents via six-membered chelates to give the diastereomerically enriched (R)- and (S)-adducts, respectively, which, after chiral auxiliary removal by reductive N-O bond cleavage, led to the corresponding (R)- and (S)-1-(aryl)ethylamines. This organolithium addition protocol using methyllithium was applied in an enantiodivergent fashion to the preparation of both enantiomers of 1-(2-hydroxyphenyl)ethylamine, which has been previously used as an efficient chiral auxiliary for the synthesis of natural products in this laboratory. The synthetic utility of this methodology involving diastereoselective methyl addition was demonstrated by further application to the asymmetric synthesis of a new type of calcium receptor agonist (calcimimetics), (R)-(+)-NPS R-568 and its thio analogue. Furthermore, diastereoselective vinylation was accomplished by application of the hydroxy oxime ether-based protocol using vinyllithium, which allowed the development of the enantioselective synthesis of the NK-1 receptor antagonists, (+)-CP-99,994 and (+)-CP-122,721.
Enantioselective synthesis of 1-aryl-2-propenylamines: A new approach to a stereoselective synthesis of the Taxol side chain
Castagnolo, Daniele,Armaroli, Silvia,Corelli, Federico,Botta, Maurizio
, p. 941 - 949 (2007/10/03)
A variety of substituted 1-aryl-2-propenylamines of high enantiomeric purity were prepared via lipase-catalysed resolution of the corresponding racemates. (R)-1-Phenyl-2-propenylamine was further synthesised into (2R,3S)-3-benzoylamino-2-hydroxy-3-phenylpropanoic acid methyl ester, the side chain of Taxol.
