54594-06-8Relevant academic research and scientific papers
Synthesis of chiral cyclic nitrones via a nitrosoketene intermediate and their use for the complete EPC synthesis of nonproteinogenic amino acids
Katagiri, Nobuya,Okada, Makoto,Kaneko, Chikara,Furuya, Toshio
, p. 1801 - 1804 (1996)
New cyclic chiral nitrones constituting two diastereomers were synthesized by the reaction of isonitroso Meldrum's acid with l-menthone via a nitrosoketene intermediate. Both nitrones reacted with allyltrimelhylsilane diastereoselectively to give the corresponding isoxazolidine derivatives as sole products, which were converted to (S)- and (R)-allylglycines in ca. 100% ee, respectively.
Asymmetric [2,3]-rearrangement of glycine-derived allyl ammonium ylids
Workman, James A.,Garrido, Neil P.,Sancon, Julien,Roberts, Edward,Wessel, Hans Peter,Sweeney
, p. 1066 - 1067 (2005)
The first examples of highly enantioselective [2,3]-sigmatropic rearrangements of acyclic allylic ammonium ylids are reported. Thus, a range of N-{2′-[(N′-allyl-N′,N′-dialkyl)ammonium]}acetyl camphor sultams undergo rearrangement at 0 °C in DME solution with high diastereofacial control (up to 99:1 dr) to give allylglycines in generally high yield. The power of the method has been demonstrated in a rapid and efficient synthesis of (R)-allyl glycine. Copyright
Epoxy amino acids produced from allylglycines intramolecularly cyclised to yield four stereoisomers of 4-hydroxyproline derivatives
Krishnamurthy, Suvratha,Arai, Toru,Nakanishi, Kanae,Nishino, Norikazu
, p. 2482 - 2490 (2014/01/06)
Derivatives of 2-amino-4-pentenoic acid (allylglycine) were efficiently resolved using Subtilisin or acylase. The side-chain unsaturated bond of the enantiomerically pure amino acid with tert-butoxycarbonyl (Boc) protection was smoothly epoxidized with m-chloroperbenzoic acid. When the Boc protection of the amino group was removed, the amino group intramolecularly attacked the side-chain epoxide, generating compounds with five-membered rings: the 4-hydroxyproline derivatives. Two diastereomeric products were formed through the cyclisation reaction, for example, (2S,4S)-4-hydroxyproline benzyl ester (cis-8) and (2S,4R)-4-hydroxyproline benzyl ester (trans-8) were formed from (2S)-amino acid with a side-chain epoxide. Compound (2S,4S)-4-hydroxyproline benzyl ester (cis-8) was transformed to a lactone (cis-hydroxyproline lactone, 10) with the removal of benzyl alcohol. The cis-conformation was essential for the intramolecular ester exchange reaction; in fact, no lactone formation was observed for the trans isomer (trans-8). The separation of cis-hydroxyproline lactone and the trans-isomeric hydroxyproline benzyl ester was facile and clear, in contrast to the difficult separation of cis- and trans-hydroxyproline derivatives. Thus, two diastereomers of hydroxyproline derivatives for l-hydroxyproline and also for d-hydroxyproline were obtained, i.e., four diastereomers of hydroxyproline derivatives.
Diastereoselective amidoallylation of glyoxylic acid with chiral tert-butanesulfinamide and allylboronic acid pinacol esters: Efficient synthesis of optically active γ,δ-unsaturated α-amino acids This work is dedicated to Dr. Masanori Sakamoto, Professor Emeritus of Meiji Pharmaceutical University, on the occasion of his 77th birthday (KIJU)
Sugiyama, Shigeo,Imai, Saori,Ishii, Keitaro
, p. 1069 - 1074 (2013/10/08)
A convenient synthesis of δ,γ-unsaturated amino acids has been developed. After a mixture of (R)-tert-butanesulfinamide and glyoxylic acid with molecular sieves in CH2Cl2 was stirred for 42 h at room temperature, allylboronic acid pinacol ester was added to the mixture to give (R)-2-((R)-tert-butanesulfinamido)pent-4-enoic acid with high diastereoselectivity. The corresponding reaction of (Z)-crotylboronic acid pinacol ester produced no product; however, that of (E)-crotylboronic acid pinacol ester produced (2R,3S)-2-((R)-tert-butylsulfinamido)-3-methylpent-4- enoic acid with excellent diastereoselectivity.
Novel preparation of chiral α-amino acids using the Mitsunobu-Tsunoda reaction
Noisier, Anais F. M.,Harris, Craig S.,Brimble, Margaret A.
supporting information, p. 7744 - 7746 (2013/09/02)
An efficient synthesis of racemic or optically active α-amino acids by modified-Mitsunobu alkylation of a racemic or chiral glycine template from alcohols was developed. Libraries of amino acids were prepared in moderate to good yield with good to high enantioselectivity. This simple method widens the scope for preparation of structurally diverse amino acids.
An improved racemase/acylase biotransformation for the preparation of enantiomerically pure amino acids
Baxter, Scott,Royer, Sylvain,Grogan, Gideon,Brown, Fraser,Holt-Tiffin, Karen E.,Taylor, Ian N.,Fotheringham, Ian G.,Campopiano, Dominic J.
supporting information, p. 19310 - 19313 (2013/02/23)
Using directed evolution, a variant N-acetyl amino acid racemase (NAAAR G291D/F323Y) has been developed with up to 6-fold higher activity than the wild-type on a range of N-acetylated amino acids. The variant has been coupled with an enantiospecific acylase to give a preparative scale dynamic kinetic resolution which allows 98% conversion of N-acetyl-dl-allylglycine into d-allylglycine in 18 h at high substrate concentrations (50 g L-1). This is the first example of NAAAR operating under conditions which would allow it to be successfully used on an industrial scale for the production of enantiomerically pure α-amino acids. X-ray crystal analysis of the improved NAAAR variant allowed a comparison with the wild-type enzyme. We postulate that a network of novel interactions that result from the introduction of the two side chains is the source of improved catalytic performance.
Phase-transfer enantioselective monoalkylation of prochiral nickel(ii) complexes catalyzed by 3,3′-bis[hydroxy(diphenyl)methyl]-1,1′- binaphthyl-2,23′-diol (BIMBOL) as a route to α-amino acids
Belokon,Maleev,Samoilichenko,Moskalenko,Hakobyan,Saghyan
, p. 2344 - 2349 (2013/10/01)
An achiral nickel complex with a Schiff base derived from glycine was alkylated with alkyl halides under conditions of asymmetric phase-transfer catalysis. The chiral tetraol (R)-BIMBOL was employed as a catalyst. The enantiomeric purity of the alkylation products was up to 88%. Subsequent decomposition of the complexes afforded the corresponding a-amino acids.
Rapid asymmetric synthesis of amino acids via NiII complexes based on new fluorine containing chiral auxiliaries
Saghyan, Ashot S.,Dadayan, Ani S.,Dadayan, Slavik A.,Mkrtchyan, Anna F.,Geolchanyan, Arpine V.,Manasyan, Luiza L.,Ajvazyan, Hrant R.,Khrustalev, Victor N.,Hambardzumyan, Hasmik H.,Maleev, Victor I.
experimental part, p. 2956 - 2965 (2011/03/19)
New fluorine-containing chiral auxiliaries (S)-N-(2-benzoylphenyl)-1-(2- fluorobenzyl)-, (S)-N-(2-benzoylphenyl)-1-(3-fluorobenzyl)-, and (S)-N-(2-benzoylphenyl)-1-(4-fluorobenzyl)-pyrrolidine-2-carboxamide and their NiII complexes of Schiff bases with glycine and alanine have been synthesized. The greater efficiency of the complexes in terms of faster reaction rates and stereoselectivities in the asymmetric synthesis of (S)-α-amino acids has also been demonstrated.
Remarkable salt effect on in-mediated allylation of N-tert-butanesulfinyl imines in aqueous media: Highly practical asymmetric synthesis of chiral homoallylic amines and isoindolinones
Sun, Xing-Wen,Liu, Min,Xu, Ming-Hua,Lin, Guo-Qiang
supporting information; experimental part, p. 1259 - 1262 (2009/04/06)
A highly practical and efficient asymmetric synthesis of chiral homoallylic amines by In-mediated allylation of chiral N-tert-butanesulfinyl imines in aqueous media at room temperature was developed. With 2-formylbenzoate imine substrates, the method allows the highly enantioselective achievement of a variety of pharmacologically important 3-allyl isoindolinone compounds.
Large scale enantiomeric synthesis, purification, and characterization of ω-unsaturated amino acids via a Gly-Ni(II)-BPB-complex
Gu, Xuyuan,Ndungu, John M.,Qiu, Wei,Ying, Jinfa,Carducci, Michael D.,Wooden, Hank,Hruby, Victor J.
, p. 8233 - 8243 (2007/10/03)
The enantiomeric syntheses of ω-unsaturated amino acids and β-substituted ω-unsaturated amino acids were accomplished by using Gly-Ni-2[N-(N′-benzylprolyl)amino]benzophenone (BPB) as a chiral auxiliary. The synthesis provides excellent yields and high diastereoselectivities. The product crystallization followed by isomer epimerization strategy makes the reaction practical and useful for large-scale preparations. Dialkylation of the Ni(II)-complex, which was designed for mechanistic considerations, revealed that high diastereoselectivity is obtained due to the thermodynamic conformational stability of the Ni(II)-complex. The assignment of absolute configuration was accomplished by NMR, which is supported by corresponding X-ray structure and optical rotation data. Both enantiomerically pure amino acids can be synthesized in this alkylation-hydrolysis two-step strategy in multi gram scales.
