Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Scalable synthesis of Fmoc-protected GalNAc-threonine amino acid and T(N) antigen via nickel catalysis.

ABSTRACT: The highly ?-selective and scalable synthesis of the Fmoc-protected GalNAc-threonine amino acid and TN antigen in gram scale (0.5-1 g) is described. The challenging 1,2-cis-2-amino glycosidic bond is addressed through a coupling of threonine residues with C(2)-N-ortho-(trifluoromethyl)benzylidenamino trihaloacetimidate donors mediated by Ni(4-F-PhCN)4(OTf)2. The desired 1,2-cis-2-amino glycoside was obtained in 66% yield (3.77 g) with ?-only selectivity and subsequently transformed into the Fmoc-protected GalNAc-threonine and TN antigen. This operationally simple procedure no longer requires utilization of the commonly used C(2)-azido donors and overcomes many of the limitations associated with the synthesis of 1,2-cis linkage.

SUBMITTER: Yu F

PROVIDER: S-EPMC4752204 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Scalable synthesis of Fmoc-protected GalNAc-threonine amino acid and T(N) antigen via nickel catalysis.

Yu Fei F McConnell Matthew S MS Nguyen Hien M HM

Organic letters 20150408 8

The highly α-selective and scalable synthesis of the Fmoc-protected GalNAc-threonine amino acid and TN antigen in gram scale (0.5-1 g) is described. The challenging 1,2-cis-2-amino glycosidic bond is addressed through a coupling of threonine residues with C(2)-N-ortho-(trifluoromethyl)benzylidenamino trihaloacetimidate donors mediated by Ni(4-F-PhCN)4(OTf)2. The desired 1,2-cis-2-amino glycoside was obtained in 66% yield (3.77 g) with α-only selectivity and subsequently transformed into the Fmoc ...[more]

PMID: 25853273

Similar Datasets

Correction to "Development of Fmoc-Protected Bis-Amino Acids toward Automated Synthesis of Highly Functionalized Spiroligomers".

Project description: Not available

| S-EPMC9942684 | biostudies-literature

Synthesis of protected norcysteines for SPPS compatible with Fmoc-strategy.

Project description:We report the synthesis of racemic Alloc-Ncy(Tmob)-OH, the resolution of its methyl ester, and demonstrate its application to form a norcystine bridge in octreotide-amide using the Fmoc-strategy on solid phase. N-Alloc and S-Tmob protections of norcysteine (Ncy) were found to be a preferred choice for Fmoc-strategy over three other protected norcysteines synthesized i.e. Fmoc-Ncy(tBu)-OH, Alloc-Ncy(tBu)-OH and Alloc-Ncy(Trt)-OH.

| S-EPMC2701708 | biostudies-literature

Asymmetric Synthesis of Protected Unnatural α-Amino Acids via Enantioconvergent Nickel-Catalyzed Cross-Coupling.

Project description:Interest in unnatural α-amino acids has increased rapidly in recent years in areas ranging from protein design to medicinal chemistry to materials science. Consequently, the development of efficient, versatile, and straightforward methods for their enantioselective synthesis is an important objective in reaction development. In this report, we establish that a chiral catalyst based on nickel, an earth-abundant metal, can achieve the enantioconvergent coupling of readily available racemic alkyl electrophiles with a wide variety of alkylzinc reagents (1:1.1 ratio) to afford protected unnatural α-amino acids in good yield and ee. This cross-coupling, which proceeds under mild conditions and is tolerant of air, moisture, and a broad array of functional groups, complements earlier approaches to the catalytic asymmetric synthesis of this valuable family of molecules. We have applied our new method to the generation of several enantioenriched unnatural α-amino acids that have previously been shown to serve as useful intermediates in the synthesis of bioactive compounds.

| S-EPMC8351905 | biostudies-literature

Synthesis of an Fmoc-threonine bearing core-2 glycan: a building block for PSGL-1 via Fmoc-assisted solid-phase peptide synthesis.

Project description:Selectins (L, E, and P) are vascular endothelial molecules that play an important role in the recruitment of leukocytes to inflamed tissue. In this regard, P-Selectin glycoprotein-1 (PSGL-1) has been identified as a ligand for P-Selectin. PSGL-1 binds to P-Selectin through the interaction of core-2 O-glycan expressing sialyl Lewis(x) oligosaccharide and the three tyrosine sulfate residues. Herein, we report the synthesis of threonine-linked core-2 O-glycan as an amino acid building block for the synthesis of PSGL-1. This building block was further incorporated in the Fmoc-assisted solid-phase peptide synthesis to provide a portion of the PSGL-1 glycopeptide.

| S-EPMC2902660 | biostudies-literature

Scalable and Selective β-Hydroxy-α-Amino Acid Synthesis Catalyzed by Promiscuous l-Threonine Transaldolase ObiH.

Project description:Enzymes from secondary metabolic pathways possess broad potential for the selective synthesis of complex bioactive molecules. However, the practical application of these enzymes for organic synthesis is dependent on the development of efficient, economical, operationally simple, and well-characterized systems for preparative scale reactions. We sought to bridge this knowledge gap for the selective biocatalytic synthesis of β-hydroxy-α-amino acids, which are important synthetic building blocks. To achieve this goal, we demonstrated the ability of ObiH, an l-threonine transaldolase, to achieve selective milligram-scale synthesis of a diverse array of non-standard amino acids (nsAAs) using a scalable whole cell platform. We show how the initial selectivity of the catalyst is high and how the diastereomeric ratio of products decreases at high conversion due to product re-entry into the catalytic cycle. ObiH-catalyzed reactions with a variety of aromatic, aliphatic and heterocyclic aldehydes selectively generated a panel of β-hydroxy-α-amino acids possessing broad functional-group diversity. Furthermore, we demonstrated that ObiH-generated β-hydroxy-α-amino acids could be modified through additional transformations to access important motifs, such as β-chloro-α-amino acids and substituted α-keto acids.

| S-EPMC8796315 | biostudies-literature

Convenient Synthesis of Acetonide Protected 3,4-Dihydroxyphenylalanine (DOPA) for Fmoc Solid-Phase Peptide Synthesis.

Project description:We report a facile approach to the synthesis of acetonide and Fmoc protected 3,4-dihydroxyphenylalanine (DOPA), Fmoc-DOPA(acetonide)-OH. By protecting the amino group of DOPA with a phthaloyl group and the carboxyl group as a methyl ester, acetonide protection of the catechol of DOPA derivative was realized in the presence of p-toluenesulfonic acid. Following removal of protecting groups, the intermediate was converted to Fmoc-DOPA(acetonide)-OH, which was successfully incorporated into a short DOPA-containing peptide, derived from marine tubeworm cement proteins Pc1 and Pc2.

| S-EPMC2598405 | biostudies-literature

Efficient synthesis of Fmoc-protected phosphinic pseudodipeptides: Building blocks for the synthesis of matrix metalloproteinase inhibitors.

Project description:A convenient route for the synthesis of Fmoc-protected phosphinic dipeptide building blocks is described. The protected amino acid isosteres benzyloxycarbonyl aminomethyl phosphinic acid (glycine surrogate), benzyl ?-isopropyl acrylate (valine surrogate), and benzyl ?-isobutyl acrylate (leucine surrogate) were synthesized starting from commercially available materials. Reaction of either the valine or leucine surrogate with bis(trimethylsilyl) phosphonite generated the pseudodipeptide bond. The synthesis concluded with an efficient one-pot three-step procedure involving a bis-deprotection of the N- and C-termini under catalytic hydrogenation conditions followed by selective capping of the N-terminus with an Fmoc group to yield either Fmoc-NHCH(2) PO(OAd)CH(2) CH(Pr(i) )CO(2) H or Fmoc-NHCH(2) PO(OAd)CH(2) CH(Bu(i) )CO(2) H.

| S-EPMC3307803 | biostudies-literature

One-Step Synthesis of 3-(Fmoc-amino acid)-3,4-diaminobenzoic Acids.

Project description:A one-step method for synthesizing 3-(Fmoc-amino acid)-3,4-diaminobenzoic acids was used to prepare preloaded diaminobenzoate resin. The coupling of free diaminobenzoic acid and Fmoc-amino acids gave pure products in 40-94% yield without any purification step in addition to precipitation except for histidine. For the proline residue, crude products were collected and used for solid-phase peptide synthesis to give a moderate yield of a pentapeptide. In addition, this method was used to prepare unusual amino acid derivatives, namely, (2-naphthyl) alanine and 6-aminohexanoic acid derivatives, in 50 and 65% yield, respectively.

| S-EPMC10634083 | biostudies-literature

Chiral aldehyde-nickel dual catalysis enables asymmetric α-propargylation of amino acids and stereodivergent synthesis of NP25302.

Project description:The combined catalytic systems derived from organocatalysts and transition metals exhibit powerful activation and stereoselective-control abilities in asymmetric catalysis. This work describes a highly efficient chiral aldehyde-nickel dual catalytic system and its application for the direct asymmetric α-propargylation reaction of amino acid esters with propargylic alcohol derivatives. Various structural diversity α,α-disubstituted non-proteinogenic α-amino acid esters are produced in good-to-excellent yields and enantioselectivities. Furthermore, a stereodivergent synthesis of natural product NP25302 is achieved, and a reasonable reaction mechanism is proposed to illustrate the observed stereoselectivity based on the results of control experiments, nonlinear effect investigation, and HRMS detection.

| S-EPMC9701212 | biostudies-literature

Highly Regioselective Indoline Synthesis under Nickel/Photoredox Dual Catalysis.

Project description:Nickel/photoredox catalysis is used to synthesize indolines in one step from iodoacetanilides and alkenes. Very high regioselectivity for 3-substituted indoline products is obtained for both aliphatic and styrenyl olefins. Mechanistic investigations indicate that oxidation to Ni(III) is necessary to perform the difficult C-N bond-forming reductive elimination, producing a Ni(I) complex, which in turn is reduced to Ni(0). This process serves to further demonstrate the utility of photoredox catalysts as controlled single electron transfer agents in multioxidation state nickel catalysis.

| S-EPMC4586280 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data