4307-98-6Relevant articles and documents
Diels-Alder Cycloaddition of Azepino[4,5-b]indoles Towards Hydrocarbazole Derivatives and Related Heterocycles
Cheng, Maosheng,Li, Xiang,Lin, Bin,Liu, Yongxiang,Ma, Jun,Sun, Lei,Xie, Fukai,Xu, Liangyu,Zhang, Bo
supporting information, (2022/01/26)
An approach to hydrocarbazoles bearing an all-carbon quaternary center at C4a position was developed via a Br?nsted acid-initiated Diels-Alder cycloaddition/retro-aza-Michael addition cascade process from azepino[4,5-b]indoles and commercially available d
Tryptamine derivatives disarm colistin resistance in polymyxin-resistant gram-negative bacteria
Barker, William T.,Chandler, Courtney E.,Melander, Roberta J.,Ernst, Robert K.,Melander, Christian
, p. 1776 - 1788 (2019/03/21)
The last three decades have seen a dwindling number of novel antibiotic classes approved for clinical use and a concurrent increase in levels of antibiotic resistance, necessitating alternative methods to combat the rise of multi-drug resistant bacteria. A promising strategy employs antibiotic adjuvants, non-toxic molecules that disarm antibiotic resistance. When co-dosed with antibiotics, these compounds restore antibiotic efficacy in drug-resistant strains. Herein we identify derivatives of tryptamine, a ubiquitous biochemical scaffold containing an indole ring system, capable of disarming colistin resistance in the Gram-negative bacterial pathogens Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli while having no inherent bacterial toxicity. Resistance was overcome in strains carrying endogenous chromosomally-encoded colistin resistance machinery, as well as resistance conferred by the mobile colistin resistance-1 (mcr-1) plasmid-borne gene. These compounds restore a colistin minimum inhibitory concentration (MIC) below the Clinical & Laboratory Sciences Institute (CLSI) breakpoint in all resistant strains.
Br?nsted Acid-Catalyzed Tandem Cyclizations of Tryptamine-Ynamides Yielding 1H-Pyrrolo[2,3-d]carbazole Derivatives
Wang, Yanshi,Lin, Jingsheng,Wang, Xiaoyu,Wang, Guanghui,Zhang, Xinhang,Yao, Bo,Zhao, Yuandong,Yu, Pengfei,Lin, Bin,Liu, Yongxiang,Cheng, Maosheng
supporting information, p. 4026 - 4032 (2018/01/15)
Ynamides, as versatile synthetic precursors, have attracted much attention from synthetic chemists and sparked the development of a number of methodologies for the construction of various structures. 1H-Pyrrolo[2,3-d]carbazole is a core scaffold of a series of monoterpene indole alkaloids found in Kopsia, Strychnos, and Aspidosperma, for example. In this study, 1H-pyrrolo[2,3-d]carbazole derivatives were synthesized by a Br?nsted acid-catalyzed tandem cyclization starting from tryptamine-based ynamides. This strategy prevented Wagner–Meerwein rearrangement by instantaneous intramolecular nucleophilic trapping of the indoleninium to afford a tetracyclic indoline via an in situ-formed enol species induced by the formation of a more stable conjugate diene moiety. The functional group tolerances were investigated by using a series of readily available substrates. A plausible mechanism has been proposed based on the evidence of the capture of the hemiaminal intermediate. Lastly, a Büchi ketone, which is the pivotal intermediate in the synthesis of the indole alkaloid vindorosine, was synthesized by utilizing our newly developed methodology.
