15027-14-2Relevant articles and documents
Syntheses of Thailandepsin B Pseudo-Natural Products: Access to New Highly Potent HDAC Inhibitors via Late-Stage Modification
Breit, Bernhard,Brosowsky, Jana,Herp, Daniel,Jung, Manfred,Keller, Manfred,Liebich, Amelie,Lutterbeck, Monika,Vogelmann, Anja
supporting information, p. 16241 - 16245 (2020/12/01)
New Thailandepsin B pseudo-natural products have been prepared. Our synthetic strategy offers the possibility to introduce varying warheads via late stage modification. Additionally, it gives access to the asymmetric branched allylic ester moiety of the natural product in a highly diastereoselective manner applying rhodium-catalyzed hydrooxycarbonylation. The newly developed pseudo-natural products are extremely potent and selective HDAC inhibitors. The non-proteinogenic amino acid d-norleucine was obtained enantioselectively by a recently developed method of rhodium-catalyzed hydroamination.
Chemical Dynamic Thermodynamic Resolution and S/R Interconversion of Unprotected Unnatural Tailor-made α-Amino Acids
Wang, Shuni,Zhou, Shengbin,Wang, Jiang,Nian, Yong,Kawashima, Aki,Moriwaki, Hiroki,Ace?a, José L.,Soloshonok, Vadim A.,Liu, Hong
, p. 9817 - 9830 (2015/11/03)
Described here is an advanced, general method for purely chemical dynamic thermodynamic resolution and S/R interconversion of unprotected tailor-made α-amino acids (α-AAs) through intermediate formation of the corresponding nickel(II)-chelated Schiff bases. The method features virtually complete stereochemical outcome, broad substrate generality (35 examples), and operationally convenient conditions allowing for large-scale preparation of the target α-AAs in enantiomerically pure form. Furthermore, the new type of nonracemizable axially chiral ligands can be quantitatively recycled and reused, rendering the whole process economically and synthetically attractive.
Chiral oxime ethers in asymmetric synthesis. 3. Asymmetric synthesis of (R)-N-protected α-amino acids by the addition of organometallic reagents to the ROPHy oxime of cinnamaldehyde
Moody, Christopher J.,Gallagher, Peter T.,Lightfoot, Andrew P.,Slawin, Alexandra M. Z.
, p. 4419 - 4425 (2007/10/03)
A new asymmetric synthesis of α-amino acids is described in which the key step is the diastereoselective addition of organometallic reagents to (R)-O-(1-phenylbutyl)cinnamaldoxime 5 to give hydroxylamines 6. Subsequent reductive cleavage of the N-O bond in the hydroxylamine 6 followed by N- protection gave the carbamates 7, which upon oxidation with ruthenium(III) chloride/periodate gave the N-protected amino acids 8. The method was also adapted to the synthesis of a quaternary amino acid 15 from the ketoxime ether 9.
Addition of Organolithiums to the (R)-O-(1-Phenylbutyl)hydroxylamine (ROPHy) Oxime of Cinnamaldehyde. Asymmetric Synthesis of α-Aminoacids
Moody, Christopher J.,Lightfoot, Andrew P.,Gallagher, Peter T.
, p. 659 - 660 (2007/10/03)
A new asymmetric synthesis of α-aminoacids is described in which the key step is the diastereoselective addition of organolithium reagents to (R)-O-(1-phenylbutyl) cinnamaldoxime.
Relaxing substrate specificity in antibody-catalyzed reactions: Enantioselective hydrolysis of N-Cbz-amino acid esters
Tanaka, Fujie,Kinoshita, Keiko,Tanimura, Ryuji,Fujii, Ikuo
, p. 2332 - 2339 (2007/10/03)
For a catalytic antibody to be generally useful for organic synthetic chemistry, it must be able to accept a broad range of substrates, yet retain high selectivity. In this work, we propose a hapten design to endow antibody catalysts with two opposing qualities, such as high enantioselectivity and broad substrate specificity. Racemic hapten 2 induced two separate classes of catalytic antibodies to hydrolyze either the L- or D-isomers of N-Cbz-amino acid esters 1. In the kinetic resolution of racemic ester 9, antibodies 7G12 and 3G2 gave 96% ee of L-10 and 94% ee of D-10, respectively. In addition, antibody 7G12 displayed broad substrate specificity, hydrolyzing the L-esters of Ala (1a), Leu (1b), Norleu (1c), Met (1d), Phe (1e), Val (1f), and phenylglycine (1g) with high enantioselectivity. Antibody 3G2 also hydrolyzed the D-isomers of these esters without sacrificing the enantioselectivity. This observation suggests that the use of haptens that fit snugly into the antigen-combining site, and leave the linker moiety outside, is an effective approach for the generation of catalytic antibodies with high selectivity and broad substrate applicability.
Porcine Pancreatic Lipase Catalyzed Enantioselective Hydrolysis of Esters of N-Protected Unusual Amino Acids
Miyazawa, Toshifumi,Iwanaga, Hitoshi,Ueji, Shinichi,Yamada,Takashi,Kuwata, Shigeru
, p. 2219 - 2222 (2007/10/02)
Porcine pancreatic lipase catalyzed the highly enantioselective hydrolysis of a kind of α-substituted carboxylic esters, i.e., the 2,2,2-trifluoroethyl esters of the N-benzyloxycarbonyl derivatives of unusual amino acids.
Direct Optical Resolution of Carboxylic Acids by Chyral HPLC on Tris(3,5-dimethylphenylcarbamate)s of Cellulose and Amylose
Okamoto, Yoshio,Aburatani, Ryo,Kaida, Yuriko,Hatada, Koichi
, p. 1125 - 1128 (2007/10/02)
A variety of racemic carboxylic acids have been for the first time directly resolved by normal-phase, high-performance liquid chromatography using a hexane-2-propanol eluting system containing a small amount (ca. 1percent) of a strong carboxylic acid, like formic acid, trichloroacetic acid, and trifluoroacetic acid.
PAPAIN-ASSISTED RESOLUTION OF NATURAL AND XENOBIOTIC α-AMINO ACIDS
Moriniere, J. L.,Danree, B.,Lemoine, J.,Guy, A.
, p. 441 - 444 (2007/10/02)
A new and convenient method for the preparation of pure enantiomers of α-amino acids is described.Industrial papain, catalyzes the synthesis of L-Z-amino acid ethyl esters in ethanolic medium, with good yields.These esters are obtained from DL-Z-amino acids with 100percent optical purity.Unreactive D-Z-amino acids are readily isolated from reaction medium.Physical constants of natural and xenobiotic L-Z-amino acid esters and D-Z-amino acids are described.
Optical Resolution of Unusual Amino-Acids by Lipase-catalysed Hydrolysis
Miyazawa, Toshifumi,Takitani, Tadanori,Ueji, Shinichi,Yamada, Takashi,Kuwata, Shigeru
, p. 1214 - 1216 (2007/10/02)
The 2-chloroethyl esters of the N-benzyloxycarbonyl (Z) derivatives of several unusual amino-acids are converted by Aspergillus niger lipase into enantiomerically enriched Z-amino-acids with fairly high optical purities, the L-enantiomers being preferentially hydrolysed.
Allylic Selenides in Organic Synthesis: New Methods for the Synthesis of Allylic Amines
Shea, Regan G.,Fitzner, Jeffrey N.,Fankhauser, John E.,Spaltenstein, Andreas,Carpino, Philip A.,et al.
, p. 5243 - 5252 (2007/10/02)
Oxidative rearrangement of allylic selenides in the presence of various amine nucleophiles provides synthetic access to a variety of allylic amine derivatives.The stereochemical outcome of these reactions has been investigated, and is consistent with a -sigmatropic rearrangement mechanism.Several D-α-amino acids and racemic β,γ-unsaturated α-amino acids were prepared in this manner.A variant of this process employing an achiral allylic selenide and chiral amide afforded protected allylic amines in low diastereoisomeric excess.
