13122-99-1Relevant articles and documents
Chemoselective Intramolecular Formal Insertion Reaction of Rh–Nitrenes into an Amide Bond Over C?H Insertion
Kono, Masato,Harada, Shingo,Nemoto, Tetsuhiro
supporting information, p. 3119 - 3124 (2019/02/13)
The past few decades have witnessed extensive efforts to disclose the unique reactivity of metal–nitrenes, because they could be a powerful synthetic tool for introducing the amine functionality into unactivated chemical bonds. The reactivity of metal–nitrenes, however, is currently mainly confined to aziridination (an insertion into a C=C bond) and C?H amination (an insertion into a C?H bond). Nitrene insertion into an amide C?N bond, however, has not been reported so far. In this work we have developed a rhodium-catalyzed one-nitrogen insertion into amide C?N and sulfonamide S?N bonds. Experimental and theoretical analyses based on density functional theory indicate that the formal amide insertion proceeds via a rhodium-coordinated ammonium ylide formed between the nitrene and the amide nitrogen, followed by acyl group transfer concomitant with C?N bond cleavage. Mechanistic studies have allowed rationalization of the origin of the chemoselectivity observed between the C?H and amide insertion reactions. The methodology presented herein is the first example of an insertion of nitrene into amide bonds and provides facile access to unique diazacyclic systems with an N?N bond linkage.
Synthesis and evaluation of novel benzimidazole conjugates incorporating amino acids and dipeptide moieties
Bu?day, Nesrin,Kü?ükbay, F. Zehra,Apohan, Elif,Kü?ükbay, Hasan,Serinda?, Ayfer,Ye?ilada, ?zfer
, p. 198 - 206 (2017/06/21)
Background: Amino acids, short peptide sequences and benzimidazole derivatives play an increasingly important role as therapeutics in areas including antibacterial, antifungal, antiviral, antiinflammatory, antiparasitic, antibiofilm, antidiabetic, and anticancer. Methods: Some novel amino acids and glycine-glycine dipeptide benzimidazole conjugates were synthesized by facile acylation reactions through DCC mediated reactions and their structures were identified by 1H-NMR, 13C-NMR and FT-IR spectroscopic techniques and elemental analysis. In vitro antimicrobial activities of some compounds against Gram positive (Staphylococcus aureus and Enterobacter faceium NJ-1) and Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and yeasts (Candida albicans and Candida tropicalis) were determined by MIC method. Their antioxidant activities were also detected by DPPH method. Results: Sixteen novel benzimidazole conjugates incorporating glycine, alanine, phenylalanine, cysteine and glycine-glycine dipeptide were synthesized and their structures were identified by spectroscopic techniques and elemental analysis. All of the compounds tested showed in vitro antimicrobial and antioxidant activities. Conclusion: Sixteen novel benzimidazole amino acid/dipeptide conjugates were synthesized using DCC mediated one step reaction in moderate yield and high purity, under mild reaction conditions, with full retention of the original chirality. Amino acid or dipeptide substitutions at position 1 of the benzimidazoles were synthesized first time in this work. The results have indicated that the newly synthesized compounds possess low to moderate antimicrobial and antioxidant activities.
Discovery of Fluoromethylketone-Based Peptidomimetics as Covalent ATG4B (Autophagin-1) Inhibitors
Qiu, Zongxing,Kuhn, Bernd,Aebi, Johannes,Lin, Xianfeng,Ding, Haiyuan,Zhou, Zheng,Xu, Zhiheng,Xu, Danqing,Han, Li,Liu, Cheng,Qiu, Hongxia,Zhang, Yuxia,Haap, Wolfgang,Riemer, Claus,Stahl, Martin,Qin, Ning,Shen, Hong C.,Tang, Guozhi
supporting information, p. 802 - 806 (2016/08/24)
ATG4B or autophagin-1 is a cysteine protease that cleaves ATG8 family proteins. ATG4B plays essential roles in the autophagosome formation and the autophagy pathway. Herein we disclose the design and structural modifications of a series of fluoromethylketone (FMK)-based peptidomimetics as highly potent ATG4B inhibitors. Their structure-activity relationship (SAR) and protease selectivity are also discussed.
