5691-19-0Relevant articles and documents
Synthesis, characterization, and nucleophilic ring opening reactions of cyclohexyl-substituted β-haloamines and aziridinium ions
Chong, Hyun-Soon,Sun, Xiang,Chen, Yunwei,Wang, Meng
, p. 946 - 948 (2015/01/30)
Cyclohexyl-substituted β-haloamines and aziridinium ions were prepared and characterized. Stereospecific ring opening of aziridinium ions was applied for efficient synthesis of vicinal amine, β-amino acid, and tetrahydroisoquinoline (THIQ) analogues. Nucleophilic ring opening reactions of aziridinium ions and N-protected aziridine analogues were for the first time comparatively studied. The result of nucleophilic reactions clearly indicates that aziridinium ions were significantly more reactive toward nucleophilic ring opening than the aziridine analogues.
Isothiourea-mediated asymmetric O- to C-carboxyl transfer of oxazolyl carbonates: Structure-selectivity profiles and mechanistic studies
Joannesse, Caroline,Johnston, Craig P.,Morrill, Louis C.,Woods, Philip A.,Kieffer, Madeleine,Nigst, Tobias A.,Mayr, Herbert,Lebl, Tomas,Philp, Douglas,Bragg, Ryan A.,Smith, Andrew D.
, p. 2398 - 2408 (2012/03/27)
The structural motif within a series of tetrahydropyrimidine-based isothioureas necessary for generating high asymmetric induction in the asymmetric Steglich rearrangement of oxazolyl carbonates is fully explored, with crossover and dynamic 19F NMR experiments used to develop a mechanistic understanding of this transformation. Copyright
PEPTIDES AND PEPTIDOMIMETIC COMPOUNDS, THE MANUFACTURING THEREOF AS WELL AS THEIR USE FOR PREPARING A THERAPEUTICALLY AND/OR PREVENTIVELY ACTIVE PHARMACEUTICAL COMPOSITION
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, (2010/04/25)
Peptides, peptidomimetics and derivatives thereof of the general formula I: H2N-GHRPX1-β-X4X5X6X7X8X9X10-X11 (I), in which X1-X10 denote one of the 20 genetically coded amino acids, wherein X8, X9 and X10 may also denote a single chemical bond;X11 denotes OR1 in which R1 equals hydrogen or (C1-C10) alkyl NR2R3 with R2 and R3 are equal or different and denote hydrogen, (C1-C10) alkyl, or a residue —W-PEG5-60K, in which the PEG residue is attached via a suitable spacer W to the N-atom, ora residue NH—Y-Z-PEG5-60K, in whichY denotes a chemical bond or a genetically coded amino acids from the group S, C, K or R andZ denotes a spacer, via which a polyethylene glycol (PEG)-residue can be attached, and their physiologically acceptable salts, andβ denotes an amino acid, or a peptidomimetic element, which induces a bend or turn in the peptide backbone.
Synthesis and characterisation of helical β-peptide architectures that contain (S)-β3-HDOPA(crown ether) derivatives
Dutot, Laurence,Gaucher, Anne,Elkassimi, Khadidja,Drapeau, Jeremy,Wakselman, Michel,Mazaleyrat, Jean-Paul,Peggion, Cristina,Formaggio, Fernando,Toniolo, Claudio
supporting information; scheme or table, p. 3154 - 3163 (2009/04/11)
A new set of β-amino acids that carry various crown ether receptors on their side chains of the general formula (S)-β3-HDOPA(crown ether) (HDOPA: homo-3,4-dihydroxyphenylalanine; (crown ether): [15]crown-5 ([15-C-5]), [18]crown-6 ([18-C-6]), [21]crown-7 ([21-C-7]), 1,2-Benzo-[24]crown- 8 ([Benzo-24-C-8]) and (R)-Binol-[20]crown-6 ([(R)-Binol-20-C-6])) was prepared. Peptides that are based on these new crowned β-amino acids combined with (1S,2S)-ACHC (2-aminocyclohexanecarboxylic acid), which is known to be a potent 314-helix inducer, to the hexamer level, with two crowned residues at the i and i+3 posi_tions of the main-chain, were synthesized in solution by stepwise coupling using Boc-Na-protection (Boc: tert-butoxycarbonyl) and the EDC/HOAt Cactivation method. Their conformational analysis was performed by using FTIR absorption, NMR and CD spectroscopy techniques. Our results are in full agreement with a 314-helix conformation.
Toward a rational design of the assembly structure of polymetallic asymmetric catalysts: design, synthesis, and evaluation of new chiral ligands for catalytic asymmetric cyanation reactions
Fujimori, Ikuo,Mita, Tsuyoshi,Maki, Keisuke,Shiro, Motoo,Sato, Akihiro,Furusho, Sanae,Kanai, Motomu,Shibasaki, Masakatsu
, p. 5820 - 5831 (2008/02/03)
New chiral ligands (4 and 5) for polymetallic asymmetric catalysts were designed based on the hypothesis that the assembled structure should be stable when made from a stable module 8. A metal-ligand=5:6+μ-oxo+OH complex was generated from Gd(OiPr)3 and 4 or 5, and this complex was an improved asymmetric catalyst for the desymmetrization of meso-aziridines with TMSCN and conjugate addition of TMSCN to α,β-unsaturated N-acylpyrroles, compared to the previously reported catalysts derived from 1-3. These two groups of catalysts produced opposing enantioselectivity even though the ligands had the same chirality. The functional difference in the asymmetric catalysts is derived from differences in the higher-order structure of the polymetallic catalysts.
Catalytic enantioselective desymmetrization of meso-N-acylaziridines with TMSCN
Mita, Tsuyoshi,Fujimori, Ikuo,Wada, Reiko,Wen, Jianfeng,Kanai, Motomu,Shibasaki, Masakatsu
, p. 11252 - 11253 (2007/10/03)
A catalytic enantioselective desymmetrization of meso-N-p-nitrobenzoylaziridines with TMSCN was developed using a chiral gadolinium catalyst generated from Gd(OiPr)3 and d-glucose-derived ligand 1. In this reaction, the addition of a
Synthesis of enantiopure cis- and trans-2-aminocyclohexane-1-carboxylic acids from octahydroquinazolin-4-ones
Priego, Jaime,Flores, Patricia,Ortiz-Nava, Claudia,Escalante, Jaime
, p. 3545 - 3549 (2007/10/03)
The chemoselective and diastereoselective hydrogenation of 2,3-dihydro-3-[(S)-α-methylbenzyl]-4-quinazolinone 2 affords octahydroquinazolinones cis-3 and cis-4. Epimerization of cis-3 and cis-4 using t-BuO-K+ produces trans-5 and tra
Asymmetric synthesis of a new helix-forming β-amino acid: trans-4-aminopiperidine-3-carboxylic acid
Schinnerl, Marina,Murray, Justin K.,Langenhan, Joseph M.,Gellman, Samuel H.
, p. 721 - 726 (2007/10/03)
We report a synthesis of a protected derivative of trans-4aminopiperidine-3-carboxylic acid (APiC). The route provides either enantiomer. All intermediates are purified by crystallization, and large-scale preparation is therefore possible. An analogous ro
Experimental determination of the absolute enantioselectivity of an antibody-catalyzed Diels-Alder reaction and theoretical explorations of the origins of stereoselectivity
Cannizzaro, Carina E.,Ashley, Jon A.,Janda,Houk
, p. 2489 - 2506 (2007/10/03)
The exo and endo Diels-Alder adducts of p-methoxycarbonylbenzyl trans-1,3-butadiene-1-carbamate and N,N-dimethylacrylamide have been synthesized, and the absolute configurations of resolved enantiomers have been determined. On the basis of this information, the absolute enantioselectivities of the Diels-Alder reaction catalyzed by antibodies 13G5 and 4D5 as well as other catalytic antibodies elicited in the same immunizations have been established. The effects of different arrangements of catalytic residues on the structure and energetics of the possible Diels-Alder transition states were modeled quantum mechanically at the B3LYP/6-311++G**//B3LYP/6-31+G** level of theory. Flexible docking of these enantiomeric transition states in the antibody active site followed by molecular dynamics on the resulting complexes provided a prediction of the transition -state binding modes and an explanation of the origin of the observed enantioselectivity of antibody 13G5.
Structure - Activity studies of 14-helical antimicrobial β-peptides: Probing the relationship between conformational stability and antimicrobial potency
Raguse, Tami L.,Porter, Emilie A.,Weisblum, Bernard,Gellman, Samuel H.
, p. 12774 - 12785 (2007/10/03)
Antimicrobial α-helical α-peptides are part of the host-defense mechanism of multicellular organisms and could find therapeutic use against bacteria that are resistant to conventional antibiotics. Recent work from Hamuro et al. has shown that oligomers of
