- Palladium-Catalyzed Decarbonylation of Amino Acid Derivatives via C-C Bond and C-N Bond Dual Activations
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A unique decarbonylation of an amino acid derivative catalytic system has been established via palladium-catalyzed C-C bond and C-N bond dual activations. By employing 8-aminoquinoline as the directing group, this transformation has been found to facilitate the high chemoselectivity to decarbonylation of amino acid derivatives rather than intramolecular deamination or cross-dehydrogenative coupling reactions. This method provides a straightforward avenue for constructing diverse functionalized amide compounds in good to excellent yields. We proposed a possible reaction pathway that may go through the C-C bond and C-N bond dual activations on the basis of the mechanistic studies.
- Deng, Gongtao,Jiang, Yaojia,Jiao, Yongjuan,Li, Yingmei,Wu, Jiamin,Zhang, Jinli,Zhang, Zhengyu
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p. 17462 - 17470
(2021/12/02)
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- A Novel Class of 7-Membered Heterocyclic Compounds
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The work presented herein describes the synthesis of a formerly inaccessible class of heterocyclic compounds. The reaction relies on α-phthalimido-amides, which are readily prepared from amino acids in 2 simple reactions steps. Under amide activation conditions in which classical keteniminium ions are not formed, the nitrile solvent is incorporated into the new fused 7-membered ring system. Due to the absence of a keteniminium intermediate, the stereogenic information in the α-position is fully retained.
- Bauer, Adriano,Borsos, Eszter,Maulide, Nuno
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supporting information
p. 3971 - 3974
(2020/05/25)
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- Tetrasubstituted Furans by Nucleophile-Induced Cleavage of Carbonyl Ylide-DMAD Cycloadducts
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Compounds incorporating a 4-aza-8-oxabicyclo[3.2.1]oct-6-en-2-one moiety, which were prepared by a tandem carbenoid carbonyl ylide cyclization/[3+2]-cycloaddition reaction from ethyl 2-diazo-3-oxo-4-phthalimidobutanoates, undergo a nucleophile-induced two-bond ring cleavage when treated with protic heteronucleophiles. In this manner, tetrasubstituted furantricarboxylates, tethered with α-amino acids, esters, thioesters, and amides by a 2-carbonylphenyl moiety, are obtained.
- Dobesch, Matthias,Greiner, Julian,Maas, Gerhard
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p. 2987 - 3000
(2020/08/10)
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- Synthesis and study of modified polyvinyl alcohol containing amino acid moieties as anticancer agent
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A series of new phthalimides compounds[3-7]a-i were synthesized from reaction of Malic anhydride, phthalic anhydride, nitro phthalic anhydride, 2-phenyl-4H-benzo[d][1,3]oxazin-4-one, 2-(4-nitrophenyl)-4H-benzo[d][1,3]oxazin-4-one with different amino acids as glycine, alanine, valine, leucine, isoleucine, serine, threonine, tyrosine and Phenyl alanine [1]a-i under fusion conditions. Compounds [3-7]a-i react with SOCl2 in the presence of benzene to produce compounds [8-12]a-i. Chemical modification of Poly(vinyl alcohol)were obtained by reaction of PVA with compounds [8-12]a-i using the dimethyl formamide to give compounds [13-17]a-i. The structure of the synthesized compounds was characterized by their analytical and spectral data as, IR spectra, 1H, 13C-NMR, Elemental analysis (CHN), UV-Vis Spectroscopy, Scanning electron microscopy (SEM), Antibacterial activity were screened via two kinds of bacteria. Also, anticancer activity were examined for most of the modified polyvinyl alcohol.
- Samir, Ali H.,Saeed, Ruwaidah S.,Matty, Fadhel S.
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p. 286 - 294
(2018/03/21)
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- Synthesis of Quaternary α-Fluorinated α-Amino Acid Derivatives via Coordinating Cu(II) Catalytic α-C(sp3)-H Direct Fluorination
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A coordinating, copper-catalyzed direct α-C(sp3)-H fluorination method has been developed to prepare vital quaternary α-fluorinated α-amino acid derivatives. A Cu(II) catalytic SET oxidative addition mechanism is proposed, involving a key fluoride-coupled Cu(II) charge transfer complex. The protocol can tolerate a rich variety of α-amino acids, for which the auxiliary group is removed in high yield and substituted for the direct preparation of dipeptide derivatives with detachable, single absolute configurations of the target compounds.
- Wei, Qiang,Ma, Yao,Li, Li,Liu, Qingfei,Liu, Zijie,Liu, Gang
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supporting information
p. 7100 - 7103
(2018/11/24)
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- Cooperative Effects between Chiral Cpx–Iridium(III) Catalysts and Chiral Carboxylic Acids in Enantioselective C?H Amidations of Phosphine Oxides
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An enantioselective C?H amidation of phosphine oxides by using an iridium(III) catalyst bearing an atropchiral cyclopentadienyl (Cpx) ligand is reported. A very strong cooperative effect between the chiral Cpx ligand and a phthaloyl tert-leucine enabled the transformation. Matched–mismatched cases of the different acid enantiomers are shown. The amidated P-chiral arylphosphine oxides are formed in yields of up to 95 % and with excellent enantioselectivities of up to 99:1 er. Enantiospecific reduction provides access to valuable P-chiral phosphorus(III) compounds.
- Jang, Yun-Suk,Dieckmann, Michael,Cramer, Nicolai
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supporting information
p. 15088 - 15092
(2017/10/11)
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- Effect of different acids addition on chiral separation of phthalylvaline by quinine carbamate based chiral stationary
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The quinine carbamate type chiral stationary phase used for direct enantiomer separation of amino acid was studied. The influence of mobile phase composition, methanol and different acids were systematically investigated to gain an insight into the overall chiral recognition mechanism.
- Fegas, Rachid,Zerkout, Said,Taberkokt, Meriem,Bettache, Zhor,Righezza, Michel
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p. 6953 - 6956
(2013/07/26)
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- Hydrogen bonding chains and rings structural motifs in new series of N-phthaloyl aminocarboxylic acid derivatives. Solid state microwave synthesis, structural chemistry, computational calculations and antimicrobial activity
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A series of six N-phthaloyl aminocarboxylic acids were synthesized by using improved microwave irradiation with a multimode reactor. X-ray single crystal diffraction established the molecular structure of three N-protected aminocarboxylic acids derivatives, and spectral data agree with these in solution. The hydrogen bonding characteristics of this class of molecules are discussed on the basis of crystal structural analyses, MP2/DFT quantum calculations and Hirshfeld surfaces analyses. The relative strengths of the structural O-H?O and C-H?O hydrogen bonding chain and ring motifs are compared. Antimicrobial activities of 2-(1,3-dioxoisoindolin-2-yl)propanoic acid, 2-(1,3-dioxoisoindolin-2-yl)-3-phenylpropanoic acid and 2-(4-(1,3-dioxoisoindolin-2-yl)phenyl)acetic acid, were screened against three pathogenic strains; only the first two compounds were found to be quite sensitive against Gram +ve and Gram -ve bacterial strains, respectively. A relative structure-function relationship is observed.
- Al-Farhan, Khalid,Ghazzali, Mohamed,Al-Hazimi, Hassan M.A.,El-Faham, Ayman,Reedijk, Jan
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scheme or table
p. 269 - 275
(2011/08/03)
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- Effect of the mobile phase acid additives on enantioselectivity of amino acid derivative using quinine carbamate based chiral stationary phase
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Quinine carbamate-type chiral stationary phase has been used for the direct liquid chromatographic enantiomer separation of a wide range of chiral acids. In the present work, we demonstrate that this the chiral stationary phase can also be extended to chiral discrimination of amino acid derivative phthalylvalin using methanol containing different organic acids in mobile phases. The influence of mobile phase composition and enantioselectivity was systematically investigated to gain insight into the overall chiral recognition mechanism.
- Fegas,Bensalem,Bettache,Ouahba,Righezza
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body text
p. 1582 - 1586
(2012/04/10)
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- Catalytic asymmetric protonation of α-amino acid-derived ketene disilyl acetals using P -Spiro diaminodioxaphosphonium barfates as chiral proton
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Chiral diaminodioxaphosphonium salts have been developed and their unique abilities as a chiral proton have been revealed through the establishment of a highly enantioselective protonation of α-amino acid-derived ketene disilyl acetals.
- Uraguchi, Daisuke,Kinoshita, Natsuko,Ooi, Takashi
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supporting information; experimental part
p. 12240 - 12242
(2010/11/19)
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- Structure-driven design and synthesis of chiral dioxocyclam derivatives
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Based on an analysis of previously reported structures and a potential geometry fit with substrates, a new family of chiral dioxocyclam derivatives have been designed. The synthesis of those ligands was accomplished starting from l-proline and α-d-amino acids (converted to β-amino acids) with a key step of macrocyclization reaction of amino esters. All ligands were converted into neutral copper(II) complexes (amide groups underwent deprotonation of upon treatment of ligands with copper(II) acetate). The complexes exhibit the desired shape of their active surfaces, as proved by X-ray analysis.
- Achmatowicz, Micha?,Szumna, Agnieszka,Zieliński, Tomasz,Jurczak, Janusz
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p. 9031 - 9041
(2007/10/03)
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- The synthesis of N-acyl-2-hydroxymethyl aziridines of biological interest
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A practical synthesis of the title compounds from protected amino acylazides is described. All the compounds might be considered as a novel class of dipeptide isostere precursors; they all induce lymphocyte proliferation and protein production as observed from preliminary biological tests.
- Medjahed,Tabet Zatla,Kajima Mulengi,Baba Ahmed,Merzouk
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p. 1211 - 1213
(2007/10/03)
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- The influence of α-amido/thioamido functionality in ester reduction with sodium borohydride
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Sodium borohydride in methanol smoothly reduces the esters of α-amino acids having N-acyl (orthioacyl)-N-alkyl (-NRCOR′ or -NRCSR′) substituents, producing amino alcohol derivatives. Esters with α-NHCOR or-CONRR′ functionality however remain unaffected. Electron-withdrawing property of the substituent appears to play a crucial role, anion formation with -NHCOR group perhaps diminishing its effect.
- Roy, Atanu,Bar, Narayan C.,Achari, Basudeb,Mandal, Sukhendu B.
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p. 644 - 650
(2007/10/03)
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- Stereoselective Reactions of Phthalimido-Substituted Radicals Derived from (±)-Threonine: A Comparison with Reactions of N-Phthaloyliminium Ions
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Stereoselective reactions of phthalimido-substituted radicals derived from (±)-threonine with different radical traps are reported (Scheme 3, Table 1). A strong influence of the nature of the radical trap on the stereoselectivity was noticed. Small nucleophilic radical traps gave preferentially the syn products. The observed selectivities are explained with the A1.3 strain model and depend on steric and electronic effects (Fig. 2). Reactions with electrophilic radical traps such as diphenyl diselenide gave the anti diastereoisomers with moderate stereocontrol, presumably due to stereoelectronic effects. The same stereochemical outcome, i.e., preferential formation of the anti products, was observed for the reactions of the related N-phthaloyliminium ion (Scheme 5, Table 2). The stereochemistry of the ionic reaction is rationalized by a Felkin-Anh model (Fig. 3).
- Stojanovic, Aleksandar,Renaud, Philippe,Schenk, Kurt
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p. 268 - 284
(2007/10/03)
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- Restricted rotation about Nsp2-Csp3 bond through π-electronic interactions : A1H NMR study
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The electronic repulsion of a carboxyl group from a phenyl ring has been found to restrict rotation about Nsp2-Csp3 bond. A stable sp3-geometry of a carbon in N-CHR-COOH derivatives of a,β-(9,10-dihydroanthracene-9,10-diyl)succinimide has been demonstrated on the basis of shielding parameters of N′-alkyls. The carboxyl group does not exhibit hydrogen bonding with the carbonyls of the succinimide and remains in anti orientation. Though the anisotropic effect of an olefinic bond is fairly small, the interaction of carboxyl group with the olefinic bond is evident in CPD-MA adduct derivative.
- Singh, Kalpana,Srivastava, Nishi,Verma, Shiva M.
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p. 142 - 145
(2007/10/03)
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- Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 7. Cyclisation of amino acid derived α-phthalimidoacyl ylides to give pyrroloisoindolediones
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A series of 11 amino acid-derived stabilised ylides 12-14 and 16 have been prepared and characterised. In one case, for compound 17, an X-ray structure determination supports formulation of the compounds as phosphonium enolates. Flash vacuum pyrolysis (FVP) of 12 and 13 at 500°C results in loss of R23PO between the ylide function and one carbonyl of the phthalimido group to give products characterised spectroscopically as the pyrroloisoindolediones 18. The identity of these is also supported by the results of 13C and 15N labelling experiments, but owing to their high reactivity complete separation from the phosphine oxide was not generally possible even when Bu3PO rather than Ph3PO was involved. Chromatographic purification of 29, similarly produced by FVP of 14, led to partial hydrolysis, rearrangement and decarboxylation to give 30. FVP of 12 at 750°C gave the 1-unsubstituted pyrroloisoindolediones 19 in two cases.
- Aitken, R. Alan,Cooper, Harris R.,Mehrotra, Amit P.
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p. 475 - 483
(2007/10/03)
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- SULFUR YLIDES. 3. SYNTHESIS OF KETO-GROUP STABILIZED AMINO-CONTAINING SULFUR YLIDES FROM AMINO ACIDS
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An effective path of synthesis was developed of new synthetic intermediates, the optically active, keto-group stabilized amino-substituted sulfur ylides.
- Tolstikov, G. A.,Galin, F. Z.,Lakeev, S. N.,Khalilov, L. M.,Sultanova, V. S.
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p. 535 - 541
(2007/10/02)
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