7518-21-0Relevant academic research and scientific papers
Selective construction of alkaloid scaffolds by alcohol-based direct and mild aerobic oxidative Pictet-Spengler reactions
Han, Feng,Li, Huan,Liu, Haicheng,Liu, Jianping,Xu, Qing
supporting information, p. 7079 - 7085 (2020/10/02)
Employing TBN/TEMPO as the catalysts and oxygen as the oxidant, the biologically and pharmaceutically significant tetrahydro-β-carboline and β-carboline alkaloid scaffolds that used to be obtained by multi-step processes can now be selectively obtained in only one-stepviadirect aerobic oxidative Pictet-Spengler reactions of tryptamines with alcohols under mild conditions, with water generated as the byproduct. In this reaction, TBN/TEMPO was interestingly found to be able to facilitate the cyclization step of the whole reaction. This method tolerates a variety ofC- andN-substituted tryptamines, and both the more reactive benzylic and allylic alcohols and the less reactive aliphatic alcohols. This method can also be extended to dihydro-β-carboline synthesis and applied to the more available and more economical tryptophan for β-carboline synthesis, revealing its broad substrate scope and potential in synthetic applications.
Selective Methylation of Amides, N-Heterocycles, Thiols, and Alcohols with Tetramethylammonium Fluoride
Cheng, Hong-Gang,Pu, Maoping,Kundu, Gourab,Schoenebeck, Franziska
supporting information, p. 331 - 334 (2019/12/30)
We herein disclose the use of tetramethylammonium fluoride (TMAF) as a direct and selective methylating agent of a variety of amides, indoles, pyrroles, imidazoles, alcohols, and thiols. The method is characterized by operational simplicity, wide scope, and ease of purification. Our computational studies suggest a concerted methylation-deprotonation as the preferred reaction pathway.
Sequential One-Pot Vilsmeier-Haack and Organocatalyzed Mannich Cyclizations to Functionalized Benzoindolizidines and Benzoquinolizidines
Outin, Johanne,Quellier, Pauline,Bélanger, Guillaume
, p. 4712 - 4729 (2020/03/30)
The development of new one-pot sequential cyclizations involving a Vilsmeier-Haack reaction followed by an organocatalyzed Mannich reaction is reported. This synthetic strategy gives access to functionalized indolizidines and quinolizidines in one operation from readily synthesized precursors. Yields and diastereoselectivities are good to excellent when formamides are used to trigger the key step, bearing either an electron-rich aryl or a pyrrole as the nucleophilic partner in the first cyclization.
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.
Tryptamine Synthesis by Iron Porphyrin Catalyzed C?H Functionalization of Indoles with Diazoacetonitrile
Hock, Katharina J.,Knorrscheidt, Anja,Hommelsheim, Renè,Ho, Junming,Weissenborn, Martin J.,Koenigs, Rene M.
, p. 3630 - 3634 (2019/02/13)
The functionalization of C?H bonds with non-precious metal catalysts is an important research area for the development of efficient and sustainable processes. Herein, we describe the development of iron porphyrin catalyzed reactions of diazoacetonitrile with N-heterocycles yielding important precursors of tryptamines, along with experimental mechanistic studies and proof-of-concept studies of an enzymatic process with YfeX enzyme. By using readily available FeTPPCl, we achieved the highly efficient C?H functionalization of indole and indazole heterocycles. These transformations feature mild reaction conditions, excellent yields with broad functional group tolerance, can be conducted on gram scale, and thus provide a unique streamlined access to tryptamines.
Combined Approach of Backbone Amide Linking and On-Resin N-Methylation for the Synthesis of Bioactive and Metabolically Stable Peptides
Wesche, Frank,Adihou, Hélène,Kaiser, Astrid,Wurglics, Mario,Schubert-Zsilavecz, Manfred,Kaiser, Marcel,Bode, Helge B.
supporting information, p. 3930 - 3938 (2018/05/14)
Rhabdopeptides are a large class of nonribosomal peptides from the bacteria Xenorhabdus and Photorhabdus with low micromolar activity against different protozoa, which are the causative agents of several tropical diseases. The development of a facile and flexible synthesis combining backbone amide linking with on-resin peralkylation for the synthesis of permethylated rhabdopeptides is described. This strategy allows the fast generation of permethylated naturally occurring and artificial rhabdopeptides for a structure-activity study. Furthermore, in vitro experiments revealed their superior properties regarding their stability and passive membrane diffusion.
BICYCLIC HETEROAROMATIC UREA OR CARBAMATE COMPOUNDS FOR USE IN THERAPY
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Page/Page column 99; 100, (2019/01/08)
The present invention relates to bicyclic heteroaromatic urea or carbamate compounds of formula I where the variables are as defined in the claims and the description. The invention moreover relates to a pharmaceutical composition containing these compounds I, and to these compounds for use in therapy, especially for use in the treatment or prevention of a disease or disorder selected from the group consisting of an inflammatory disease, a hyperproliferative disease or disorder, a hypoxia-related pathology and a disease characterized by excessive vascularization.
Ynesulfonamide-Based Silica Gel and Alumina-Mediated Diastereoselective Cascade Cyclizations to Spiro[indoline-3,3′-pyrrolidin]-2-ones under Neat Conditions
Wang, Yanshi,Wang, Xiaoyu,Lin, Jingsheng,Yao, Bo,Wang, Guanghui,Zhao, Yuandong,Zhang, Xinhang,Lin, Bin,Liu, Yang,Cheng, Maosheng,Liu, Yongxiang
supporting information, p. 1483 - 1492 (2018/03/01)
The spiro[indoline-3,3′-pyrrolidin]-2-ones were synthesized via a silica gel and alumina-mediated sequential transformation based on tryptamine-derived ynesulfonamide substrates under neat conditions. The inherent tendency of C?C bond migration through Wagner-Meerwein rearrangement in the synthesis of spirooxindole was prevented by water trapping to the spiroindoleninium intermediate. The functional group tolerances of the methodology were investigated using a variety of substrates. The detailed mechanism of the sequential transformation was probed by the isotope-labeled experiments. This strategy was further applied in the formal syntheses of indole alkaloids coerulescine and horsfiline. (Figure presented.).
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.
Potentiation of Francisella resistance to conventional antibiotics through small molecule adjuvants
Stephens, Matthew D.,Hubble, Veroncia B.,Ernst, Robert K.,Van Hoek, Monique L.,Melander, Roberta J.,Cavanagh, John,Melander, Christian
supporting information, p. 128 - 131 (2016/01/30)
A screen of 20 compounds identified small molecule adjuvants capable of potentiating antibiotic activity against Francisella philomiragia. Analogue synthesis of an initial hit compound led to the discovery of a potentially new class of small molecule adjuvants containing an indole core. The lead compound was able to lower the MIC of colistin by 32-fold against intrinsically resistant F. philomiragia.
