119153-87-6Relevant articles and documents
The development and application of a novel safety-catch linker for BOC-based assembly of libraries of cyclic peptides
Bourne,Golding,McGeary,Meutermans,Jones,Marshall,Alewood,Smythe
, p. 7706 - 7713 (2001)
Cyclic peptides are appealing targets in the drug-discovery process. Unfortunately, there currently exist no robust solid-phase strategies that allow the synthesis of large arrays of discrete cyclic peptides. Existing strategies are complicated, when synthesizing large libraries, by the extensive workup that is required to extract the cyclic product from the deprotection/cleavage mixture. To overcome this, we have developed a new safety-catch linker. The safety-catch concept described here involves the use of a protected catechol derivative in which one of the hydroxyls is masked with a benzyl group during peptide synthesis, thus making the linker deactivated to aminolysis. This masked derivative of the linker allows BOC solid-phase peptide assembly of the linear precursor. Prior to cyclization, the linker is activated and the linear peptide deprotected using conditions commonly employed (TFMSA), resulting in deprotected peptide attached to the activated form of the linker. Scavengers and deprotection adducts are removed by simple washing and filtration. Upon neutralization of the N-terminal amine, cyclization with concomitant cleavage from the resin yields the cyclic peptide in DMF solution. Workup is simple solvent removal. To exemplify this strategy, several cyclic peptides were synthesized targeted toward the somatostatin and integrin receptors. From this initial study and to show the strength of this method, we were able to synthesize a cyclic-peptide library containing over 400 members. This linker technology provides a new solid-phase avenue to access large arrays of cyclic peptides.
Traceless selenocarboxylates for the one-pot synthesis of amides and derivatives
Silva, Luana,Rosário, Alisson R.,Machado, Bianca M.,Lüdtke, Diogo S.
supporting information, (2020/12/25)
We have recently reported a one-pot procedure for glycosyl amides synthesis using selenocarboxylate as traceless reagent. Herein, we present a further application of selenocarboxylate-azide reaction for amide bond formation on a broader range of substrates, including heterocyclic systems and fatty acid. This method proved to be highly efficient for the synthesis of primary and secondary amides, sulfonamides, imides, phosphoramide and also carbamate.
Synthesis of Acetaminophen Analogues Containing α-Amino Acids and Fatty Acids for Inhibiting Hepatotoxicity
Imai, Nobuyuki,Jung, Seunghee,Kawashima, Yuya,Noguchi, Takuya
, p. 3686 - 3696 (2019/09/30)
Acetaminophen is a popular antipyretic analgesic medicine that has weaker anti-inflammatory properties and lower incidence of side effects than nonsteroidal anti-inflammatory drugs (NSAIDs). However, acetaminophen causes hepatotoxicity due to the reactive metabolite N -acetyl- p -benzoquinone imine (NAPQI). We have obtained acetaminophen analogues in 57-99percent yields by using aniline derivatives with protected α-amino acids and fatty acids via the corresponding mixed carbonic carboxylic anhydrides in aqueous MeCN. We have also succeeded in synthesizing AM404 analogues in 76-97percent yields, which are expected to be promising candidates for reducing hepatotoxicity.
Highly Diastereo- and Enantioselective Michael Addition of Nitroalkanes to 2-Enoyl-Pyridine N-Oxides Catalyzed by Scandium(III)/Copper(II) Complexes
Li, Lijun,Zhang, Sheng,Hu, Yanbin,Li, Yanan,Li, Chong,Zha, Zhenggen,Wang, Zhiyong
supporting information, p. 12885 - 12888 (2015/09/07)
A C2-symmetric Schiff-base ligand, derived from tridentate-Schiff-base, was developed and successfully applied to the asymmetric Michael addition of nitroalkanes to 2-enoyl-pyridine N-oxides. With this newly catalytic system, an unprecedented diastereoselectivity was obtained in the asymmetric Michael addition of nitroalkanes to 2-enoyl-pyridine N-oxides. In addition, a switch in enantioselectivity was achieved by using this newly catalytic system and our previous catalyst. After a facile reduction, the optically active adduct was converted to a biologically active dihydro-2H-pyrrol 4a. Furthermore, a connection of two tridentate-Schiff-base subunits proved to be an effective strategy in ligand design. Complex chemistry! A C2-symmetric Schiff-base ligand, derived from tridentate-Schiff-base, was developed and successfully applied to the asymmetric Michael addition of nitroalkanes to 2-enoyl-pyridine N-oxides with unprecedented diastereoselectivity (see scheme).
