- Amber force field implementation, molecular modelling study, synthesis and MMP-1/MMP-2 inhibition profile of (R)- and (S)-N-hydroxy-2-(N-isopropoxybiphenyl-4-ylsulfonamido)-3-methylbutanamides
-
Ab initio calculations (B3LYP/Lanl2DZ level of theory) were performed in this study to determine all the structural and catalytic zinc parameters required in order to study MMPs and their complexes with hydroxamate inhibitors by means of the AMBER force f
- Tuccinardi, Tiziano,Martinelli, Adriano,Nuti, Elisa,Carelli, Paolo,Balzano, Federica,Uccello-Barretta, Gloria,Murphy, Gillian,Rossello, Armando
-
-
Read Online
- First total synthesis of neoantimycin
-
The first total synthesis of neoantimycin (1), an unusual ring-extended antibiotic of the antimycin class, has been achieved, using intramolecular transesterification for construction of the 15-membered tetralactone core.
- Ogawa, Hikaru,Iio, Hideo,Usuki, Yoshinosuke
-
-
Read Online
- 3-Aminoquinazolinones as chiral ligands in catalytic enantioselective diethylzinc and phenylacetylene addition to aldehydes
-
A series of readily known enantiomerically pure 3-aminoquinazolinones 1a-d were synthesised from easily accessible chiral pool α-hydroxy acids and α-amino acids in only four steps without any requirement of chromatography. These quinazolinones were examined as chiral ligands for catalytic enantioselective diethylzinc and phenylacetylene additions to aldehydes. For enantioselective alkylations, the effects of temperature, solvent, diethylzinc and ligand criteria were analysed, and the desired chiral alcohols were obtained in up to 86% ee. 3-Aminoquinazolinones 1a-d were also shown to be very useful ligands in enantioselective alkynylations of aldehydes. Based upon the optimised conditions, the corresponding propargylic alcohols were obtained in up to 94% ee.
- Karabuga, Semistan,Karakaya, Idris,Ulukanli, Sabri
-
p. 851 - 855
(2014/06/23)
-
- Synthesis of new chiral ionic liquids from α-hydroxycarboxylic acids
-
New functionalized optically active N-methylimidazolium ionic liquids with an asymmetric center at the β-position to the imdazole ring were synthesized as bromide salts from optically active α-hydroxycarboxylic acids. The bromide anions were exchanged by carboxylate anions with Amberlite IRA 400 ionic exchange resin.
- Poterala, Marcin,Plenkiewicz, Jan
-
experimental part
p. 294 - 299
(2011/05/17)
-
- Zinc-catalyzed enantiospecific sp3-sp3 cross-coupling of α-hydroxy ester triflates with grignard reagents
-
(Chemical Equation Presented) Zinc chloride does the trick and efficiently catalyzes the enantiospecific cross-coupling of α-hydroxy ester triflates with Grignard reagents under mild conditions. Enantiopure α-hydroxy esters are directly available from the chiral pool or by diazotization of α-amino acids. Substantial variations in both reacting partners are tolerated making this methodology an attractive alternative to enolate alkylation featuring a reversal of polarity.
- Studte, Christopher,Breit, Bernhard
-
supporting information; experimental part
p. 5451 - 5455
(2009/03/12)
-
- N-i-Propoxy-N-biphenylsulfonylaminobutylhydroxamic acids as potent and selective inhibitors of MMP-2 and MT1-MMP
-
Structural manipulation of the pharmacophoric model of type A selective MMP inhibitors (MMPi), obtained by the insertion of some alkyl substituents R 2 possessing an appropriate geometry, steric bulkiness and lipophilicity, is able to improve p
- Rossello, Armando,Nuti, Elisa,Carelli, Paolo,Orlandini, Elisabetta,Macchia, Marco,Nencetti, Susanna,Zandomeneghi, Maurizio,Balzano, Federica,Barretta, Gloria Uccello,Albini, Adriana,Benelli, Roberto,Cercignani, Giovanni,Murphy, Gillian,Balsamo, Aldo
-
p. 1321 - 1326
(2007/10/03)
-
- Synthesis of unsymmetrical 3,3′-biquinazoline-2,2′-diones by condensation of 3-aminoquinazolinones with benzoxazinones; fortuitous discovery, and further syntheses of 4-H-3-oxo-1,9a,10-triazaanthracen-9-ones
-
Condensation of 2-alkyl- or 2-aryl-3-aminoquinazolin-4-ones with benz[1,3]oxazin-4-ones gives the unsymmetrical 2,2′ disubstituted 3,3′ biquinazoline-4,4′-diones. The reaction is tolerant to a range of heteroatom and unsaturated functionality in the quina
- Coogan, Michael P.,Ooi, Li-Ling,Pertusati, Fabrizio
-
p. 1134 - 1139
(2007/10/03)
-
- A novel access to 2-aminofuranones via cyclization of functionalized γ-hydroxy-α,β-butenoates derived from N-hydroxybenzotriazole esters of α-hydroxy acids
-
The reaction between the N-hydroxybenzotriazole esters of substituted glycolic acids and alkyl cyanoacetates or malononitrile leads to the synthesis of γ-hydroxy-functionalized butenoates which are cyclized under mild conditions to the corresponding 2-amino-3,5-disubstituted-4-furanones. That the products are optically active is confirmed by measurements of their optical rotations. On the other hand, replacement of N-hydroxybenzotriazole by N-hydroxysuccinimide might lead to by-products depending on the functionalized glycolic acid used.
- Athanasellis, Giorgos,Detsi, Anastasia,Prousis, Kyriakos,Igglessi-Markopoulou, Olga,Markopoulos, John
-
p. 2015 - 2022
(2007/10/03)
-
- Synthesis and characterization of chiral N-O turns induced by α-aminoxy acids
-
Chiral α-aminoxy acids of various side chains were synthesized with high optical purity starting from chiral α-amino acids. The conformations of diamides 13a-e, 15, and 16 were probed by using NMR, FT-IR, and CD spectroscopic methods as well as X-ray crystallography. The right-handed turns with eight-membered-ring intramolecular hydrogen bonds between adjacent residues (called the N-O turns) were found to be preferred for D-aminoxy acid residues, and they were independent of the side chains. The rigid chiral N-O turns should have great potential in molecular design.
- Yang,Li,Ng,Yan,Qu,Wu
-
p. 7303 - 7312
(2007/10/03)
-
- Stereoisomerism in 3-[N-(2-acetoxypropanoyl)-N-acylamino]-quinazolin-4(3H)-ones, enantioselective acylating agents
-
The title compounds diacylaminoquinazolinones (DAQs) are enantioselective acylation agents for amines and a detailed study of their stereostructures was undertaken with the aim of understanding how this enantioselectivity arises. The N-N bond in these DAQs is a chiral axis. Even where both N-acyl groups are (S)-2-acetoxypropanoyl, the N-N bond is still a chiral axis because in the most stable conformation of the planar imide moiety, one exolendo orientation of the carbonyl groups is much preferred over the alternative (endolexo) as revealed by NMR spectroscopy. A conformational preference within the 2-acetoxypropanoyl grouping accounts for the presence of a single exolendo conformation in solution for some of these DAQs (see above) but an interconverting exolendo? endolexo mixture for others. Where a single exolendo conformation is present in solution, evidence is presented that this closely resembles the X-ray determined crystal structure. A mechanism for the second acylation step to form these DAQs is proposed, which involves preliminary O-acylation of the 3-(monoacylamino)quinazolinone. The Royal Society of Chemistry 2000.
- Al-Schemi, Abdullah G.,Atkinson, Robert S.,Fawcett, John,Russell, David R.
-
p. 4413 - 4421
(2007/10/03)
-
- Synthesis of chiral α-acetoxy-N-acetylamides from chiral pyrimidylalkanols by the oxidative cleavage of pyrimidine ring
-
Acetates of chiral 5-pyrimidylalkanols are transformed into chiral α- acetoxy-N-acetylamides and α-acetoxyamides without racemization in high total yields by the oxidative cleavage of pyrimidine ring using ruthenium tetroxide.
- Tanji, Shigehisa,Kodaka, Yasutaka,Shibata, Takanori,Soai, Kenso
-
p. 151 - 158
(2007/10/03)
-
- Synthesis of optically active α-hydroxy acids by kinetic resolution through lipase-catalyzed enantioselective acetylation
-
The lipase-catalyzed acetylation of a broad spectrum of racemic 2-hydroxy acids 1 to their 2-acetoxy acids 2 was shown to proceed with high enantioselectivity. Thus, the microbial lipases, in particular from Candida antarctica and Burkholderia species, are convenient biocatalysts for the synthesis of optically active 2-hydroxy acids in excellent enantioselectivity (ee values up to 99%). The absolute configurations of the 2-hydroxy acids 1 were assigned by comparison of the gas-chromatographic data with that of literature-known reference compounds, or by means of the exciton-coupled circular dichroism method (ECCD) on their bichromophoric 2-naphthoate 9-anthrylmethyl derivatives 3. These results establish that (S)-2-hydroxy acids 1 were preferentially acetylated by microbial lipases.
- Adam, Waldemar,Lazarus, Michael,Schmerder, Alexandra,Humpf, Hans-Ulrich,Saha-M?ller, Chantu R.,Schreier, Peter
-
p. 2013 - 2018
(2007/10/03)
-
- Electrogenerated chiral cationic glycine equivalents - Part 2: Chiral 3-methoxy-2,5-morpholinediones from (S)-α-hydroxy acids and dimethyl aminomalonate
-
Chiral 3-methoxy-2,5-morpholinediones which are cyclic N,O-acetals have proved to be excellent chiral cationic amino acid equivalents, especially if larger nucleophiles are employed. They are easily obtained from dipeptolides formed between chiral α-hydroxy acids and dimethyl amino malonate via regioselective electrochemical methoxylation followed by intramolecular lactonizatian after decarboxylation. The lactonization can be performed quantitatively from the open-chain peptolide by condenzation under reduced pressure at elevated temperature. The easy separation of the desired amino acid and the α-hydroxy acid being the chiral auxiliary by extraction is valuable.
- Kardassis, Georgios,Brungs, Peter,Nothhelfer, Christoph,Steckhan, Eberhard
-
p. 3479 - 3488
(2007/10/03)
-
- Electrogenerated chiral building blocks for diastereoselective amidoalkylation reactions
-
Three different electrochemical methods have been applied for the synthesis of chiral building blocks for diastereoselective amidoalkylation reactions. These are A. the direct anodic α-methoxylation of amides and carbamates; B. anodic methoxylative decarboxylation of α-amino acid derivatives (Hofer-Moest reaction) C. indirect NaCl mediated anodic α-methoxylation of α-amino acid derivatives. The application of these building blocks for the synthesis of enantiomerically pure α-amino acids, dichiral 1,2-amino alcohols and chiral 1,3-diamines is described.
- Brungs,Danielmeier,Jakobi,Nothhelfer,Stahl,Zietlow,Steckhan
-
p. 575 - 590
(2007/10/03)
-
- Enantioselective Preparation of α-Acyloxy Ketones from α-Hydroxy and α-Amino Acids
-
Various chiral α-acyloxy ketones have been easily prepared, in high yields with an excellent enantiomeric purity, by acylation of organomanganese reagents with the corresponding α-acyloxy carboxylic acid chlorides prepared from α-hydroxy and α-amino acids.
- Cahiez, Gerard,Metais, Eric
-
p. 6449 - 6452
(2007/10/02)
-
- Reactions of α-Hydroxy Carbonyl Compounds with Azodicarboxylates and Triphenylphosphine: Synthesis of α-N-Hydroxy Amino Acid Derivatives
-
Reaction of aliphatic α-hydroxy esters with azodicarboxylates and triphenylphosphine in the presence of either CbzNHOCH2Ph or trOCNHOCH2Ph provides a direct route to protected α-N-hydroxy amino acids.Similar reactions with aromatic α-hydroxy carbonyl compounds and derivatives result in predominate oxidation to the corresponding α-oxo carbonyl derivatives.
- Kolasa, Teodozyj,Miller, Marvin J.
-
p. 4978 - 4984
(2007/10/02)
-