排序方式: 共有11条查询结果,搜索用时 15 毫秒
1.
Isidore P. Decostaire 《Tetrahedron letters》2006,47(39):7057-7060
An aminooxy-containing peptide, the nucleophile partner for oxime ligations, is usually grafted on a NH2-peptide resin by activating a protected aminooxyacetic acid as an active ester. Here, we have shown that its subsequent coupling to NH2-peptide resin competes with the overacylation of the -NH-O- nitrogen and that the overacylation level increases with the basicity of the reaction mixture. Moreover, we found that overacylation is prevented when the COOH of the Aoa-derivatives is engaged in an amide bond. 相似文献
2.
Dominique Lelièvre 《Tetrahedron letters》2008,49(25):4016-4019
In the course of the chemical synthesis of human protein mitogaligin, we present here a simple method to prepare peptide thioesters using Fmoc chemistry. The hydroxyl side chain of serine was reacted with a trichloroacetimidate Wang resin to anchor it on solid phase. After peptide elongation and orthogonal unmasking of the C-terminus, the amino thioester was introduced under optimized conditions to avoid epimerization. 相似文献
3.
Marco Molteni 《Journal of fluorine chemistry》2004,125(11):1735-1743
Peptides modified with fluoroalkyl functions in key backbone positions have been scarcely studied so far. Thus, little is known about their synthesis, their structural and physico-chemical properties, and their biological features. Our interest in this field of research led to the development of stereocontrolled synthetic protocols, both in solution and in solid phase, for many different fluoroalkyl peptidomimetics, some of which are overviewed in this paper: (a) ψ[CH(CF3)NH]-peptide mimics holding a great potential as hybrids between natural peptides and hydrolytic transition state analogs; (b) trifluoromethyl (Tfm) malic peptidomimetics as micromolar inhibitors of some matrix metalloproteinases; (c) bis-Tfm analogs of Pepstatin A, that are nanomolar and selective inhibitors of the protozoal aspartyl protease Plasmepsin II. 相似文献
4.
Jeong Kyu Bang 《Tetrahedron letters》2004,45(1):99-102
Linear and cyclic olefin peptides containing the substrate sequence for human T-cell leukemia virus type-1 (HTLV-1) were efficiently synthesized on a solid support using the Horner-Emmons reaction. The precursor peptide aldehyde was prepared by oxidation of the corresponding peptide alcohol with Dess-Martin periodinane. The oxidation reaction proceeded quantitatively on a cross-linked ethoxylate acrylate resin (CLEAR) support instead of a polystyrene-based support. Cyclization on the solid support was achieved via an amide bond formation mediated by EDC/HOAt to yield a single major product. The linear olefin peptide was cleaved by HTLV-1 protease at the scissile site, whereas the cyclic olefin peptide functions as a competitive inhibitor rather than a substrate. 相似文献
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6.
Synthesis of bis-ornithine, a new Cα,α-disubstituted α-amino acid bearing orthogonally protected α and δ amine groups is reported. Bis-ornithine (bisOrn) and dipeptides containing bis-ornithine have been synthesized in solution up to multigram scale. As a first example, one of these compounds Boc-βAla-bisOrn(Alloc)2-OH has been attached to a solid support and used as template for the synthesis of a symmetrical assemblage of peptides. 相似文献
7.
Chen Liang Mira A.M. Behnam Tom R. Sundermann Christian D. Klein 《Tetrahedron letters》2017,58(24):2325-2329
Phenylglycine-containing peptides have broad applications in medicinal chemistry, but their synthetic accessibility is complicated by the risk of epimerization during solid-phase peptide synthesis (SPPS). Phenylglycine is therefore often considered a troublesome residue. This work studies the extent of Phg racemization under different Fmoc-SPPS reaction conditions. It is shown that the base-catalyzed coupling of Fmoc-Phg is the critical step for racemization. However, racemization can be reduced to a negligible level if DEPBT or COMU combined with TMP or DMP are employed during this step. Resin-bound peptides are remarkably resistant against epimerization during extended incubation under basic conditions and the free peptides were stable in buffer solutions used for biological assays. 相似文献
8.
Sang Yeul Lee 《Tetrahedron》2009,65(16):3281-3432
An efficient and convergent solution-phase synthesis of the cyclic peptide of the natural product chlorofusin, a reported inhibitor of the MDM2-p53 interaction, is detailed. 相似文献
9.
An effective solid-phase preparation of anilides from supported carboxylic acids is described by their activation as the corresponding acid chlorides with TMUCl Cl. 相似文献
10.
A concise and convergent synthesis of the C-glycoside analogue 2b of immunomodulating α-galactosylceramide OCH 1b starting from readily available 2,3,4,6-tetra-O-benzyl-d-galactose 3 and l-arabinose 6 is described. The synthesis features the nucleophilic addition of an α-ethynyl sugar 5 to the phytosphingosine-precursor aldehyde 9 and would be applicable to a variety of C-glycoside analogues of interest. 相似文献