103550-85-2Relevant academic research and scientific papers
Poly(ethylene glycol) as solvent and polymer support in the microwave assisted parallel synthesis of aminoacid derivatives
Sauvagnat,Lamaty,Lazaro,Martinez
, p. 6371 - 6375 (2000)
A Schiff base protected glycine supported on a soluble polymer such as poly(ethylene glycol) reacted readily with various electrophiles in the presence of an inorganic base under microwave activation. It was shown in this study that the polymer support also serves as solvent in these reactions. Various α-aminoacids derivatives could be synthesized using this method. (C) 2000 Elsevier Science Ltd.
Polyethylene glycol (PEG) as polymeric support and phase-transfer catalyst in the soluble polymer liquid phase synthesis of α-amino esters
Sauvagnat, Berengere,Lamaty, Frederic,Lazaro, Reneacute,Martinez, Jean
, p. 821 - 824 (1998)
α-Substituted α-amino esters were synthesized in liquid-phase by polyethylene glycol (PEG) promoted alkylation of a polyethylene glycol-supported Schiff base activated glycine ester.
Enantioenriched α-substituted glutamates/pyroglutamates via enantioselective cyclopropenimine-catalyzed Michael addition of amino ester imines
Bandar, Jeffrey S.,Lambert, Tristan H.,Seibel, Zara M.
supporting information, p. 2077 - 2084 (2021/09/02)
A procedure for the enantioselective synthesis of α-substituted glutamates and pyroglutamates via a cyclopropenimine-catalyzed Michael addition of amino ester imines is described. Enantioselectivities of up to 94% have been achieved, and a variety of functional groups were found to be compatible. The impact of the catalyst structure and imine substitution is discussed. Compared to other methods, this protocol allows for a broader and more enantioselective access to pyroglutamate derivatives.
Preparation of chiral amino esters by asymmetric phase-transfer catalyzed alkylations of schiff bases in a ball mill
Nun, Pierrick,Perez, Violaine,Calmes, Monique,Martinez, Jean,Lamaty, Frederic
, p. 3773 - 3779 (2012/04/23)
The asymmetric alkylation of Schiff bases under basic conditions in a ball mill was performed. The starting Schiff bases of glycine were prepared beforehand by milling protected glycine hydrochloride and benzophenone imine, in the absence of solvent. The Schiff base was then reacted with a halogenated derivative in a ball mill in the presence of KOH. By adding a chiral ammonium salt derived from cinchonidine, the reaction proceeded asymmetrically under phase-transfer catalysis conditions, giving excellent yields and enantiomeric excesses up to 75 %. Because an equimolar amount of starting material was used, purification was greatly simplified. Copyright
A new method for the preparation of functionalized unnatural α-H-α-amino acid derivatives
Hyett, David J.,Didonè, Mara,Milcent, Thierry J.A.,Broxterman, Quirinus B.,Kaptein, Bernard
, p. 7771 - 7774 (2007/10/03)
A new method for the preparation of α-H-α-amino acids is reported based on the α-alkylation of iminoacetic acid esters or amides. These imines are readily available by the reaction of glyoxylic acid esters with branched primary amines. The subsequent reaction with methanolic ammonia gave the corresponding iminoacetic acid amides. α-Alkylation of these imines with various electrophiles under basic conditions, followed by an acidic hydrolysis, gave α-amino acids, esters, or amides in up to 93% yield. α-Alkylation under chiral PTC conditions resulted in mono-alkylated amino acids with 90% ee.
Highly enantioselective alkylation of glycine methyl and ethyl ester derivatives under phase-transfer conditions: Its synthetic advantage
Ooi, Takashi,Uematsu, Yukitaka,Maruoka, Keiji
, p. 1675 - 1678 (2007/10/03)
Phase-transfer alkylation of the benzophenone Schiff base of glycine methyl or ethyl ester (2) was found to be catalyzed by 3,4,5-F 3-C6H2-NAS-Br [(S,S)-1] with high efficiency and excellent enantioselectivity. This procedure allows facile derivatization of the resulting alkylation products to other synthetically useful chiral building blocks.
Reaction of dihalocarbenes with N-Alkylidene amino acid esters and nitriles. Synthesis of aziridine and pyrrole amino acid derivatives
Khlebnikov,Novikov,Nikiforova,Kostikov
, p. 91 - 99 (2007/10/03)
Conditions for preparation of functionalized geminal dihaloaziridines by reaction of dihalocarbenes with N-benzhydrylidene amino acid esters and nitriles were found. The direction of transformations of the intermediate azomethine ylides depends on the structure of the latter, as deduced from MNDO calculations.
The hydrostannation of a propargylglycine derivative
Crisp, Geoffrey T.,Gebauer, Markus G.
, p. 83 - 88 (2007/10/03)
The hydrostannation of methyl (R,S)-2-(N-diphenylmethylidene) aminopent-4-ynoate induced by a wide variety of transition metal complexes has been studied. The resulting isomeric α-amino acid derivatives featured a tributylvinylstannane in the side-chain and were separated by chromatography. A total of 24 different conditions were screened for this reaction in an attempt to effect a regioselective addition of tributyltin hydride to the alkyne group. Regioisomeric mixtures were formed in all cases and for some catalysts reduction to the allylglycine derivative was also significant.
Hydroboration of vinylglycine and allylglycine as a route to boron- derivatives of α-amino acids
Denniel, Valerie,Bauchat, Patrick,Danion, Daniel,Danion-Bougot, Renee
, p. 5111 - 5114 (2007/10/03)
The hydroboration of protected vinylglycine and allylglycine with dicyclohexyl- or diisopinocampheylborane occurs chimio- and regioselectively with attachment of boron to the less substituted end of the carbon-carbon double bond. Homoserine or δ-hydroxynorvaline are readily obtained by H2O2/CH3CO2Na oxidation of dicyclohexylborane derivatives and 2-amino-4- boronobutanoic acid or 2-amino-5-boronopentanoic acid by reaction of diisopinocampheylborane derivatives with excess of ethanal and deprotection.
SYNTHESIS OF α-AMINO ACIDS USING TRANSITION METAL CATALYSIS - ALKYLATION OF SCHIFF BASES DERIVED FROM α-AMINO ACID ESTERS (REGIO, STEREO-SELECTIVITY)
Genet, J.-P.,Juge, S.,Achi, S.,Mallart, S.,Montes, Ruiz J.,Levif, G.
, p. 5263 - 5276 (2007/10/02)
A general approach to the synthesis of γ,δ-unsaturated α-amino acid esters is described.Schiff bases derived from glycine and alanine esters were alkylated in the presence of palladium or molybdenium catalysts under neutral or basic conditions using allylic carbonates, esters or halides, (20-95 percent yield).These less stabilized nucleophiles reacted with the η3 allyl species on the side opposite to the palladium and they can be classified as soft nucleophiles.The regioselectivity was studied with various unsymmetrical electrophiles.After hydrolysis, several functionalized α-amino acids of biological interest (enzymes inhibitors) were obtained.Asymmetric palladium allylic alkylation of the benzophenone imine glycine methyl ester using Pd(OAc)2 + (+)DIOP was achieved with up to 68 percent ee; the enantioselective Pd-promoted alkylation of this new and useful prochiral nucleophile for the synthesis of α-amino acids is one of the highest ee known.
