83460-84-8Relevant articles and documents
Synthesis of chiral non-racemic intermediates and Arg-Gly-Asp mimetics by CaLB-catalyzed resolution
Cardillo, Giuliana,Gennari, Arianna,Gentilucci, Luca,Mosconi, Elisa,Tolomelli, Alessandra,Troisi, Stefano
experimental part, p. 96 - 102 (2010/04/06)
The reactivity of both the ester and amine functions present in β-amino esters was tested in order to obtain the synthesis of enantiopure αvβ3 and α5β1 integrin ligands. CaLB successfully catalyzed both the enantioselective transesterification and the N-acylation of racemic β-amino esters, allowing the isolation of intermediates for the preparation of Arg-Gly-Asp (RGD) mimetic compounds. In particular, a CaLB-catalyzed amidation reaction with unprotected p-aminobenzylamine reduced the number of synthetic steps, thus avoiding protection and deprotection of the intermediate compounds. Following this procedure, RGD mimetics were isolated with high yields and enantiomeric purities.
Synthesis of N-Methyl-N-{(1S)-1-[(3R)-pyrrolidin-3-yl]ethyl} amine
Fleck, Thomas J.,McWhorter Jr., William W.,DeKam, Richard N.,Pearlman, Bruce A.
, p. 9612 - 9617 (2007/10/03)
N-Methyl-N-{(1S)-1-[(3R)-pyrrolidin-3-yl]ethyl} amine (1)1 is a key intermediate in the preparation of premafloxacin (2), which was under development as an antibiotic for use against pathogens of veterinary importance. This paper describes the development of a practical, efficient, and stereoselective process for the preparation of 1 from isobutyl (3S)-3-{methyl[(1S)-1-phenylethyl]-amino}butanoate (5c). The key steps in the synthetic sequence are an asymmetric Michael addition, which yields 5c, and a stereoselective alkylation, which yields (3S,4S)-3-allyl-1,4-dimethylazetidin-2-one (17).
One-pot hydrogenation conditions for a sequential process to (+)-monomorine
Kim, Guncheol,Jung, Sung-do,Lee, Eun-ju,Kim, Nakjeong
, p. 5395 - 5398 (2007/10/03)
(+)-Monomorine has been synthesized under mild hydrogenation conditions initiating deprotection followed by intramolecular, sequential reductive amination reactions. The precursors could be prepared concisely using B-alkyl Suzuki cross coupling of a chiral homoallylamine and a vinyl iodide or an iodofuran derivative.
NOVEL BETA-LACTAM COMPOUNDS AND PROECSS FOR PRODUCING THE SAME
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, (2008/06/13)
1. A β-lactam compound of the formula [1]; ???wherein R1 is a lower alkyl, a lower alkyl substituted by a hydroxy; R2 is a hydrogen, a lower alkyl; X is O, S, NH; m and n are 0 to 4, Y1 is a halogen, cyano, a hydroxy, an amino, a lower alkyloxy, a lower alkylamino, a carboxy, a carbamoyl, a lower alkyl, etc., Y2 is hydrogen, an alkyl, cyano, -C(R3)=NR4 (wherein R3 and R4 are hydrogen, an amino, an alkyl, etc., or R3 and R4 may combine each other together with the nitrogen atom to form a 5- to 7-membered heterocyclic group), or a pharmaceutically acceptable salt thereof, or a non-toxic ester thereof, which has an excellent antibacterial activity against Gram-positive bacteria, especially against MRSA and MRCNS.
On the enantioselective hydrogenation of isomeric β-acylamido β-alkylacrylates with chiral Rh(I) complexes - Comparison of phosphine ligands and substrates
Heller, Detlef,Holz, Jens,Komarov, Igor,Drexler, Hans-Joachim,You, Jingsong,Drauz, Karheinz,Boerner, Armin
, p. 2735 - 2741 (2007/10/03)
The rhodium(I)-catalyzed enantioselective hydrogenation of E- and Z-configured β-acylamido β-alkylacrylates as well as of isomeric mixtures has been investigated. As ligands 1,2-bisphospholanes like DuPHOS, BPE and Me4-BASPHOS have been tested,
1. Use of the Wolff Rearrangement of Diazo Ketones from Amino Acids as a Synthetic Method for the Formation of Oligonucleo-peptides: A Novel Approach to Chimeric Biomolecules
Guibourdenche, Christel,Seebach, Dieter,Natt, Francois
, p. 1 - 13 (2007/10/03)
Photolysis and Ag-benzoate-catalyzed decomposition of the diazo ketones 2 and 4 derived from Z-Ala-OH and Z-Ala-Ala-OH in the presence of oligonucleotide derivatives bearing at the 5′-terminus an NH2 instead of the OH group, or an aminohexyl phosphate group lead to Z-protected 3-aminobutanoyl and to Z-Ala-β-HAla derivatives, respectively (conjugates 12, 13, and 17-23, Schemes 3-5). In solution, this amide-forming acylation reaction could be realized only with oligomers containing up to 8 unprotected nucleotide building blocks (Schemes 3 and 4). With the analogous polymer-bound and protected oligonucleotide derivatives as amino nucleophiles, excellent yields were obtained with all chain lengths tested (up to 15mer, Scheme 5). The products were purified by reversed-phase HPLC and characterized by MALDI-TOF mass spectrometry (Figs. 2-4, Table 2) and by capillary gel electrophoresis (Fig. 2).
On the Preparation of β-Amino Acids from α-Amino Acids Using the Arndt-Eistert Reaction: Scope, Limitations and Stereoselectivity. Application to Carbohydrate Peptidation. Stereoselective α-Alkylations of Some β-Amino Acids
Podlech, Joachim,Seebach, Dieter
, p. 1217 - 1228 (2007/10/02)
The Arndt-Eistert homologation of α-amino acids was studied to determine the stereoselectivity in this reaction by chromatographic up-to-date analytical methods.While carbamate-protected phenylglycine was transformed to the corresponding β-amino acid methyl ester with a stereoselectivity of only 9:1, all other tested amino acid derivatives (Ala, Phe, Ser, Orn, tert-Leu and perhydro-azepine-2-carboxylic acid, suitably protected) were homologated with full retention of configuration (products 9-17).The intermediate diazo ketones 1-8 were purified and characterized by their NMR spectra.When nucleophiles derived from partially protected sugars were present during decomposition of the diazo ketones (derived from amino acids or dipeptides), a strong dependence of the yield (products 21-24) on the degree of steric hindrance of the nucleophilic OH group was observed.Two of the β-amino acids obtained from the homologation reaction were transformed to α-substituted (25-27, 31, 32) and α,α-disubstituted β-amino acid derivatives (28, 29) with excellent selctivities (in most cases, a single diastereoisomer was obtained). - Key Words: β-Amino acids, α-branched/Glycopeptides
Die Arndt-Eistert-Reaktion in der Peptidchemie: ein einfacher Zugang zu Homopeptiden
Podlech, Joachim,Seebach, Dieter
, p. 507 - 509 (2007/10/02)
Stichworte: Arndt-Eistert-Reaktionen. β-Aminosaeuren.Dihydrooxazinone.Homopeptide.Peptid-Analoga
Synthesis of β-Amino-acid Peptides. Part 3. Preparation of Racemic and Chiral 3-Aminobutyric Acid Derivatives and Peptides Using Dihydrooxazin-6-ones and Conventional Coupling Reagents
Drey, Charles N. C.,Mtetwa, Eli
, p. 1587 - 1592 (2007/10/02)
Peptides of R,S and S-3-aminobutyric acid have been prepared by conventional methods and also by using chiral oxazin-6-ones, the latter method proving to be superior because of the absence of the side-reactions.S-3-Aminobutyric acid derivatives were prepared by Arndt-Eistert homologation.
