291763-94-5

Upstream product

• 141209-95-2 (4S)-4-phenyl-3-[(2E)-3-phenylprop-2-enoyl]-1,3-oxazolidin-2-one 
• 56-40-6 glycine 
• 615576-88-0 N-(2-benzoylphenyl)-2-(piperidin-1-yl)acetamide 
• 98-79-3 L-Pyroglutamic acid 
• 155835-37-3 (4R)-3-(3-phenyl-2-(E)-propenoyl)-4-phenyl-2-oxazolidinone 
• 531539-18-1 (2S)-1-benzyloxycarbonyl-5-oxo-pyrrolidine-2-carboxylic acid 2-(3-methyl-oxetan-3-yl-methyl) ester 
• 531539-21-6 (2S)-5-oxo-pyrrolidine-2-carboxylic acid 3-methyl-oxetan-3-ylmethyl ester 
• 531539-28-3 (2S,3S)-2-(4-methyl-2,6,7-trioxa-bicyclo[2.2.2]oct-1-yl)-5-oxo-3-phenyl-pyrrolidine-1-carboxylic acid benzyl ester 
• 461639-00-9 (2S)-2-(4-methyl-2,6,7-trioxa-bicyclo[2.2.2]oct-1-yl)-5-oxo-pyrrolidine-1-carboxylic acid benzyl ester 
• 531539-23-8 (2S)-2-(4-methyl-2,6,7-trioxa-bicyclo[2.2.2]oct-1-yl)-5-oxo-2,5-dihydro-pyrrole-1-carboxylic acid benzyl ester 

Downstream Products

• 112419-82-6 (2S,3R)-3-phenyl-glutamic acid 
• 700365-79-3 ethyl (2S,3R)-N-tert-butoxycarbonyl-3-phenylprolinate 
• 528607-25-2 (2S,3R)-3-Phenyl-pyrrolidine-2-carboxylic acid ethyl ester 
• 464173-90-8 ethyl (2S,3R)-N-tert-butoxycarbonyl-3-phenylpyroglutamate 
• 123724-21-0 (2S,3R)-1-(tert-butoxycarbonyl)-3-phenylpyrrolidine-2-carboxylic acid 

Relevant academic research and scientific papers

Application of modular nucleophilic glycine equivalents for truly practical asymmetric synthesis of β-substituted pyroglutamic acids

A new series of achiral glycine equivalents have been evaluated with respect to their synthetic utility for the production of β-substituted pyroglutamic acid derivatives. Among them, the piperidine-derived complex was found to be a superior glycine derivative for the Michael additions with various (R)-N-(E-enoyl)-4-phenyl-1,3-oxazolidin-2-ones representing a general and practical synthesis of sterically constrained β-substituted pyroglutamic acids. In particular, application of complex allowed for the first time preparation of the corresponding isopropyl derivatives thus increasing the synthetic efficiency and expanding generality these Michael addition reactions.

NH-type of chiral Ni(ii) complexes of glycine Schiff base: Design, structural evaluation, reactivity and synthetic applications

The work being reported here deals with the design of a new type of "N-H" Ni(ii) complexes of glycine Schiff bases and study general aspects of their reactivity. It was confirmed that the presence of NH function in these Ni(ii) complexes does not interfere with the homologation of the glycine residue, rendering these derivatives of high synthetic value for the general synthesis of α-amino acids. In particular, the practical application of these NH-type complexes was demonstrated by asymmetric synthesis of various-substituted pyroglutamic acids via Michael addition reactions with chiral Michael acceptors.

Design, synthesis, and evaluation of a new generation of modular nucleophilic glycine equivalents for the efficient synthesis of sterically constrained α-amino acids

A new generation of modular achiral glycine equivalents have been evaluated with respect to their synthetic utility for the production of tailor-made, sterically constrained α-amino acids, which proved to be the most efficient approach developed to date for the synthesis of symmetrical α,α-disubstituted-α-amino acids. Among the new series of achiral glycine equivalents, one was found to be a superior glycine derivative for the Michael additions with various (R)- or (S)-N-(E-enoyl)-4-phenyl-1,3- oxazolidin-2-ones representing a general and practical synthesis of sterically constrained β-substituted pyroglutamic acids. In particular, the application of these complexes allowed for the preparation of several β-substituted pyroglutamic acids which include electron-releasing and sterically demanding substituents in the structure thus increasing the synthetic efficiency and expanding the generality of these Michael addition reactions.

Michael addition reactions between chiral equivalents of a nucleophilic glycine and (S)- or (R)-3-[(E)-enoyl]-4-phenyl-1,3-oxazolidin-2-ones as a general method for efficient preparation of β-substituted pyroglutamic acids. Case of topographically control

This paper describes a systematic study of addition reactions between the chiral Ni(II) complex of the Schiff base of glycine with (S)-o[N-(N- benzylprolyl)amino]benzophenone and (S)- or (R)-3-[(E)-enoyl]-4-phenyl-1,3- oxazolidin-2-ones as a general and s

Virtually complete control of simple and face diastereoselectivity in the Michael addition reactions between achiral equivalents of a nucleophilic glycine and (S)- or (R)-3-(E-enoyl)-4-phenyl-1,3-oxazolidin-2-ones: Practical method for preparation of β-substituted pyroglutamic acids and prolines

This study demonstrates a new strategy for controlling the stereochemical outcome of the Michael addition reactions between nucleophilic glycine equivalents and α,β-unsaturated carboxylic acid derivatives: The addition reactions between achiral Ni(II)-complex of the Schiff base of glycine with o-[N-α-pycolylamino]acetophenone and (S)- or (R)-3-(E-enoyl)-4- phenyl-1,3-oxazolidin-2-ones were shown to occur at room temperature in the presence of nonchelating organic bases and, most notably, with very high stereoselectivity at both newly formed stereogenic centers. Thus, the chiral 4-phenyl-1,3-oxazolidin-2-one moiety was found to control efficiently both face diastereoselectivities of the glycine derived enolate and the C,C double bond of the Michael acceptor. The new strategy developed in this work is methodologically superior to previous methods, most notably in terms of generality and synthetic efficiency. Excellent chemical yields and diastereoselectivities, combined with the simplicity of the experimental procedures, render the present method of immediate use for preparing various 3-substituted pyroglutamic acids and related amino acids (glutamic acids, glutamines, prolines, etc.) available via conventional transformations of the former.

A stereoselective synthesis of 3-substituted (S)-pyroglutamic and glutamic acids via OBO ester derivatives

(S)-Pyroglutamic acid is transformed to the Cbz-protected 4-methyl-2,6,7-trioxabicyclo[2.2.2] octane (OBO) ester. This ortho ester functionality is employed as a bulky steering group for stereoselective introduction of alkyl and aryl groups via 1,4-cuprate addition to 3,4-unsaturated pyroglutamates. After deprotection and ringopening, 3-substituted glutamic acids are obtained.

Michael addition reactions between chiral Ni(II) complex of glycine and 3-(trans-enoyl)oxazolidin-2-ones. A case of electron donor - Acceptor attractive interaction-controlled face diastereoselectivity

This study has demonstrated that the readily available and inexpensive 3-(trans-3′-alkyl/arylpropenoyl)oxazolidin-2-ones, featuring high electrophilicity and conformational homogeneity, are synthetically superior Michael acceptors over the conventionally used alkyl enoylates, allowing for a remarkable improvement in reactivity and, in most cases, diastereoselectivity of the addition reactions with a Ni(II) complex of the chiral Schiff base of glycine with (S)-o-[N-(N-benzylprolyl)-amino]benzophenone. Kinetically controlled diastereoselectivity in the corresponding Michael addition reactions between the Ni(II) complex of glycine and the oxazolidin-2-ones was systematically studied as a function of steric, electronic, and position effects of the substituents on the starting Michael acceptor. In both aliphatic and aromatic series the simple diastereoselectivity was found to be virtually complete, affording the products via the corresponding TSs with the approach geometry like. The face diastereoselectivity of the reactions between the Ni(II) complex of glycine and the 3-(trans-3′-alkylpropenoyl)oxazolidin-2-ones was found to depend exclusively on the steric bulk of the alkyl group on the starting Michael acceptor. In contrast, the face diastereoselectivity in the reactions of aromatic oxazolidin-2-ones with the Ni(II) complex of glycine was shown to be controlled predominantly by the electronic properties of the aryl ring. In particular, the additions of the Ni(II) complex of glycine with 3-(trans-3′-arylpropenoyl)oxazolidin-2-ones, bearing electron-withdrawing substituents on the phenyl ring, afforded the (2S,3R)-configured products with synthetically useful diastereoselectivity and in quantitative chemical yields, thus allowing for an efficient access to the sterically constrained β-aryl-substituted pyroglutamic and glutamic acids.

A practical asymmetric synthesis of enantiomerically pure 3-substituted pyroglutamic acids and related compounds

DBU-catalyzed Michael addition reactions were shown to occur at room temperature between a nickel(II) complex of the Schiff base of glycine 1 and (S)- or (R)-N-(E-enoyl)-4-phenyl-3-oxazolidin-2-ones (2, see scheme). This reaction, which has an almost comp

(S)- or (R)-3-(E-enoyl)-4-phenyl-1,3-oxazolidin-2-ones: ideal Michael acceptors to afford a virtually complete control of simple and face diastereoselectivity in addition reactions with glycine derivatives.

[formula: see text] Enantiomerically pure (S)- or (R)-3-(E-enoyl)-4-phenyl-1,3-oxazolidin-2-ones were found to serve as ideal Michael acceptors in addition reactions with achiral Ni(II) complexes of glycine Schiff bases. Virtually complete control of simple and face diastereoselectivity, observed in these reactions, combined with quantitative chemical yields renders this methodology synthetically superior to the previous methods.