NDA@SZTAKI

Origin of problems related to Staudinger reduction in carbopeptoid syntheses

Csordás, Barbara

Nagy, Adrienn

Harmat, Veronika

Zsoldosné dr. Mády, Virág

Leveles, Ibolya

Pintér, István

Farkas, Viktor

Perczel, András

Springer

2016

QD Chemistry / kémia

QD04 Organic chemistry / szerves kémia

Abstract
We report the solid phase synthesis of –GG-X-GG– type α/β-carbopeptoids incorporating RibAFU(ip) (1a, tX) or XylAFU(ip) (2a, cX) sugar amino acids. Though coupling efficacy is moderate, both the lengthier synthetic route using Fmoc derivative (e.g., Fmoc-RibAFU(ip)-OH) and the azido derivative (e.g., N3-RibAFU(ip)-OH) via Staudinger reaction with nBu3P can be successfully applied. Both X-ray diffraction, 1H- and 31P-NMR, and theoretical (QM) data
support and explain why the application of Ph3P as Staudinger reagent is “ineffective” in the case of a cis
stereoisomer, if cX is attached to the preceding residue
with a peptide (–CONH–) bond. The failure of the polypeptide chain elongation with N3-cX originates from the “coincidence” of a steric crowdedness and an electronic
effect disabling the mandatory nucleophilic attack during the hydrolysis of a quasi penta-coordinated triphenylphosphinimine. Nevertheless, the synthesis of the
above α/β-chimera peptides as completed now by a new pathway via 1,2-O-isopropylidene-3-azido-3-deoxy-ribo- and -xylo-furanuronic acid (H-RibAFU(ip)-OH 1a and H-XylAFU(ip)-OH 2a) coupled with N-protected α-amino acids on solid phase could serve as useful examples and starting points of further synthetic efforts.

magyar

Article

NonPeerReviewed

info:eu-repo/semantics/article

text

http://real.mtak.hu/47573/2/csordas-2016-aminoacids.pdf

Csordás, Barbara and Nagy, Adrienn and Harmat, Veronika and Zsoldosné dr. Mády, Virág and Leveles, Ibolya and Pintér, István and Farkas, Viktor and Perczel, András (2016) Origin of problems related to Staudinger reduction in carbopeptoid syntheses. Amino Acids, 48. pp. 2619-2633. ISSN 1438-2199

http://real.mtak.hu/47573/

http://dx.doi.org/10.1007/s00726-016-2289-x

10.1007/s00726-016-2289-x