1069-48-3Relevant articles and documents
TRANSITION METAL COMPLEXES - A NEW CLASS OF CATALYSTS OF INTERFACIAL ALKYLATION FOR THE ASYMMETRICAL SYNTHESIS OF α-AMINO ACIDS
Belokon', Yu. N.,Maleev, V. I.,Videnskaya, S. O.,Saporovskaya, M. B.,Tsyryapkin, V. A.,Belikov, V. M.
, p. 110 - 118 (1991)
A new class of catalysts of interfacial asymmetrical alkylation is suggested for the synthesis of α-amino acids - positively charged complexes of the transition metals Cu(II), Ni(II), and Pd(II).These complexes consist of several fragments, by variation of which the structure of the catalysts can readily be modified.The complexes are chiral on account of (S)proline derivatives contained in them as one of the fragments.The catalyst complexes (C) were used in alkylation of amino acid fragments of Ni(II) complexes of the Schiff base of glycine with N-(2-pyridinecarbonyl)-o-aminobenzophenone (Ni-PBP-Gly) and the Schiff base of alanine with N-(2-pyridinecarbonyl)-o-aminobenzaldehyde (Ni-PBA-Ala) under interfacial conditions.After decomposition of alkylated complexes, phenylalanine and α-methyl-phenylalanine were isolated with yields of 33-87percent and optical purity (o. p.) from 3 to 21percent, depending on the C used.
Synthesis of chiral spiro 3-oxazolin-5-one 3-oxides (Chiral nitrones) via a nitrosoketene intermediate and their asymmetric 1,3-dipolar cycloaddition reactions leading to the EPC synthesis of modified amino acids,
Katagiri, Nobuya,Okada, Makoto,Morishita, Yoshihiro,Kaneko, Chikara
, p. 5725 - 5746 (1997)
Cycloaddition of chiral cyclic ketones such as (-)-menthone, (+)-nopinone, and (+)-camphenilone to nitrosokelene generated by thermolysis of 5-hydroxyimino-2,2-dimethyl-1,3-dioxane-4,6 dione gave the corresponding chiral spiro 3-oxazolin-5-one 3-oxides (chiral cyclic nitrones). These nitrones underwent asymmetric 1,3-dipolar cycloddition reactions with electron rich olefins to give the corresponding oxazolidine derivatives with high diastereoselectivity, which were converted to optically pure amino acids.
Direct synthesis of unprotected α-amino acids via allylation of hydroxyglycine
Sugiura, Masaharu,Mori, Chieko,Hirano, Keiichi,Kobayashi, Shu
, p. 937 - 942 (2005)
Hydroxyglycine, the ammonia adduct of glyoxylic acid, was found to react with various allylboronates in the presence of triethylamine in methanol to give unprotected α-amino acids directly with high stereoselectivity. For instance, the reactions with (E)- and (Z)-crotylboronates afforded the corresponding anti- and syn-crotylated products (isoleucine and alloisoleucine after hydrogenation) with high diastereoselectivity, respectively. Interestingly, it was found that isomerization of the products (γ-adducts to α-adducts) occurred under the reaction conditions in some cases. Control experiments have suggested that the isomerization took place via 2-aza (or azonia) Cope rearrangement of imines derived from γ-adducts and glyoxylic acid.
One-Pot Synthesis of α-Amino Acids through Carboxylation of Ammonium Ylides with CO2 Followed by Alkyl Migration
Mita, Tsuyoshi,Sugawara, Masumi,Sato, Yoshihiro
, p. 5236 - 5243 (2016)
A simple, yet powerful protocol for α-amino acid synthesis using carbon dioxide (CO2) was developed. α-Amino silanes could undergo four successive reactions (formation of ammonium salt, carboxylation, esterification, and 2,3- or 1,2-Stevens rearrangement) in the presence of allylic or benzylic halides under a CO2 atmosphere (1 atm). It is noteworthy that carboxylation at the position adjacent to a nitrogen atom proceeded via an ammonium ylide intermediate under mild conditions.
Microbial enantioselective removal of the N-benzyloxycarbonyl amino protecting group
Maurs, Michele,Acher, Francine,Azerad, Robert
, p. 22 - 26 (2012/10/29)
In order to deprotect N-carbobenzoxy-l-aminoacids (Cbz-AA) and related compounds, a series of microorganisms was selected from soil by enrichment cultures with Cbz-l-Glu as sole nitrogen source. A lyophilized whole-cell preparation of two Arthrobacter sp. strains grown on Cbz-Glu or Cbz-Gly exhibited a high cleavage activity. The conditions of hydrolysis have been optimized and a quantitative enantioselective deprotection of several Cbz-dl-amino acids was obtained, as well as the deprotection of N-carbamoylester derivatives of several synthetic amino compounds. The preparation of Cbz-d-allylglycine and l-allylglycine in high yield and high optical purity is described as an application of this method.
