27720-03-2Relevant articles and documents
Asymmetric Sulfinylations of N-Methylephedrine-Modified Tri- or Tetraalkyl Zincates by Symmetric Diaryl Sulfoxides
Ruppenthal, Simon,Brückner, Reinhard
supporting information, p. 2518 - 2530 (2018/06/11)
Diethylzinc was treated with 1 or 2 equiv. of AlkMgCl or PhMgBr (preferably) or with 1 equiv. of nBuLi (less efficiently) for forming species – plausibly zincates – which were sulfinylated by diaryl sulfoxides to give racemic alkyl aryl sulfoxides in yields reaching 100 %. Dialkylzinc reagents were also activated by treatments with 1 or 2 equiv. of an enantiomerically pure alkylmagnesium β-aminoalkoxide. This worked best when the alkoxide stemmed from a dialkylmagnesium reagent and an equimolar amount of N-methyl-(–)-ephedrine. This second activation mode allowed sulfinylations of what was originally the dialkylzinc reagent with diaryl sulfoxides. This generated alkyl aryl sulfoxides with enantiomeric ratios up to 93:7 in up to 100 % yield.
Nucleophilic Fluorination and Radiofluorination via Aziridinium Intermediates: N-Substituent Influence, Unexpected Regioselectivity, and Differences between Fluorine-19 and Fluorine-18
Médoc, Marie,Sobrio, Franck
, p. 10086 - 10097 (2015/11/03)
The efficient dehydrofluorination and radiofluorination of N,N-disubstituted-β-aminoalcohols through an anchimeric-assisted mechanism was developed. An investigation into the influence of N-substituents on the ring opening of the aziridinium intermediate indicated differences in the isomeric ratio and the yields of fluorinated products obtained from N,N-disubstituted-phenylalaninol. This influence was substantial for 18F-radiofluorination, with yields varying from 0 to 71% at room temperature (RT). Although no significant effects were observed in the fluorine-19 chemistry when the reaction was heated to 90 °C, considerable changes appeared during radiofluorination. In the latter case, the radiochemical yields increased, and degradation of the 2-fluoro-propan-1-amine isomer (b) occurred, leading to a regiospecific reaction in the radiolabeling of [18F]-fluorodeprenyl. This method involving nucleophilic radiofluorination at RT was successfully applied to the radiolabeling of [18F]-2-fluoroethylamines in which the influence of the N-substituent was also observed.
Establishment of the absolute configuration of the bioactive marine alkaloid eudistomin X by stereospecific synthesis
Finlayson, Rhys,Brackovic, Amira,Simon-Levert, Annabel,Banaigs, Bernard,O'Toole, Ronan F.,Miller, Christopher H.,Copp, Brent R.
scheme or table, p. 837 - 840 (2011/03/20)
The marine β-carboline alkaloid eudistomin X has been synthesised stereospecifically, using d-phenylalanine as the chiral pool starting material, establishing the absolute configuration of the natural product as (10R). A stereospecific synthesis of both e
Synthesis and antimicrobial activity of a series of optically active quaternary ammonium salts derived from phenylalanine
Lukac, Milos,Lacko, Ivan,Bukovsky, Marian,Kyselova, Zuzana,Karlovska, Janka,Horvath, Branislav,Devinsky, Ferdinand
scheme or table, p. 194 - 201 (2010/12/19)
We synthesized nine quaternary ammonium compounds (QUATs) starting from phenylalanine, N-alkyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromides, which were prepared as optically pure substances. Five compounds were prepared as S-enantiomers and four compounds as R-enantiomers. These compounds were evaluated by their activities against bacteria and fungi. Three microbial strains were used in the study: the gram-negative bacteria Escherichia coli, the gram-positive bacteria Staphylococcus aureus and the fungi Candida albicans. The activities were expressed as minimum bactericidal or fungicidal concentrations (MBC). The most active compounds were (2S)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide and (2R)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide, with MBC values exceeding those of commercial benzalkoniumbromide (BAB) used as standard. The relationships between structure and biological activity of the tested QUATs were quantified by the bilinear model (QSAR) and are discussed. Versita Warsaw and Springer-Verlag Berlin Heidelberg.
ANESTHETIC COMPOUNDS
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Page/Page column 39, (2008/06/13)
In one embodiment the invention provides novel compounds of Formula (I) as well as prodrugs, salts, hydrates, solvates and N-oxides thereof. The invention also provides pharmaceutical compositions that include such compounds as well as methods for making and methods for using such compounds in medical therapy.
Benzazepine and benzothiazepine derivatives
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, (2008/06/13)
Vasodilating activity is exhibited by compounds having the formula STR1 wherein X can be --S--or --CH2 --; and R2 is STR2 depending upon the definition of X.
ENANTIOSELECTIVE METAL-COMPLEX CATALYSIS. IV. DEPENDENCE OF THE CONFIGURATION OF THE PRODUCT ON CONFIGURATION OF THE METAL COMPLEX IN AN ASYMMETRIC CROSS-COUPLING REACTION
Pavlov, V. A.,Klabunovskii, E. I.,Zhorov, E. Yu.,Gorshkova, L. S.,Rodin, A. P.
, p. 1009 - 1018 (2007/10/02)
Rules relating the conformation of the catalytic complex and configuration of the reaction products are proposed for the cross-coupling reactions of alkyl (aryl) or sec-alkyl Grignard reagents and organozinc compounds with derivatives of olefins in the presence of nickel complexes containing chiral diphosphine or phosphine amine ligands.The rules were checked in the cross-coupling reactions of arylmagnesium bromides with crotyl alcohol and 1-(4-isobutylphenyl)ethylmagnesium bromide with vinyl bromide in the presence of NiCl2/S-Phephos (optical yields 29-83percent).
THE REACTION OF DICHLOROCARBENE WITH β-ETHANOLAMINES. STEREOSPECIFIC SYNTHESIS OF EPOXIDES
Castedo, Luis,Castro, Jose L.,Riguera, Ricardo
, p. 1205 - 1208 (2007/10/02)
Optically pure β-ethanolamines were converted into epoxides in good yield and with high e.e. (>= 95percent) by reaction with dichlorocarbene.By this method α-aminoacids were successfully converted into synthetically useful epoxides.
Chiral β-dimethylaminoalkylphosphines. Highly efficient ligands for a nickel complex catalyzed asymmetric grignard cross-coupling reaction
Hayashi, Tamio,Fukushima, Motoo,Konishi, Mitsuo,Kumada, Makoto
, p. 79 - 82 (2007/10/02)
Chiral β-dimethylaminoalkylphosphines were prepared starting with amino acids, (S)-alanine, (S)-phenylalanine, (R)-phenylglycine, (S)-valine, and (R)-tert-leucine. The chiral phosphines were found to be highly efficient ligands for a nickel catalyzed asymmetric Grignard cross-coupling reaction (38～94% optical yield).
