- Diels-Alder Cycloaddition of Azepino[4,5-b]indoles Towards Hydrocarbazole Derivatives and Related Heterocycles
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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
- Cheng, Maosheng,Li, Xiang,Lin, Bin,Liu, Yongxiang,Ma, Jun,Sun, Lei,Xie, Fukai,Xu, Liangyu,Zhang, Bo
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supporting information
(2022/01/26)
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- Microballs Containing Ni(0)Pd(0) Nanoparticles for Highly Selective Micellar Catalysis in Water
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Both Ni(0) complexes and nanoparticles (NPs) are unstable in water, which poses a significant hindrance to their application in aqueous synthetic catalysis. To overcome these barriers, ligated Ni(0) nanoparticles (diameter 1 nm) containing a minimum amount of Pd(0) in the microballs formed of amphiphile PS-750-M are developed and applied in the highly selective carbamate cleavage. Selectivity and functional group tolerance are thoroughly investigated. Control experiments revealed the importance of an individual component of the nanocatalyst. Use of our proline-based amphiphile PS-750-M is critical for achieving microball architecture, the stability of nanoparticles, and desired catalytic activity. Once formed, microballs can be isolated and stored at ambient temperature. Catalyst is thoroughly characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, thermogravimetric analysis, infrared, and cyclic voltammetry. For selective catalysis, zero oxidation state of both Ni and Pd is crucial. On the basis of catalyst characterization and control experiments, the plausible reaction mechanism is proposed.
- Bihani, Manisha,Bora, Pranjal P.,Nachtegaal, Maarten,Jasinski, Jacek B.,Plummer, Scott,Gallou, Fabrice,Handa, Sachin
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p. 7520 - 7526
(2019/08/15)
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- Tryptamine derivatives disarm colistin resistance in polymyxin-resistant gram-negative bacteria
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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.
- Barker, William T.,Chandler, Courtney E.,Melander, Roberta J.,Ernst, Robert K.,Melander, Christian
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p. 1776 - 1788
(2019/03/21)
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- Gold(i)-catalyzed pathway-switchable tandem cycloisomerizations to indolizino[8,7-: B] indole and indolo[2,3-a] quinolizine derivatives
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Experimental and theoretical explorations were performed on the pathways of the cascade cycloisomerizations of tryptamine-N-ethynylpropiolamide substrates. The methodology provided a common strategy to access either indolizino[8,7-b]indoles or indolo[2,3-
- Liu, Chengjun,Sun, Zenghui,Xie, Fukai,Liang, Guoduan,Yang, Lu,Li, Yaqiao,Cheng, Maosheng,Lin, Bin,Liu, Yongxiang
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supporting information
p. 14418 - 14421
(2019/12/05)
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- Br?nsted Acid-Catalyzed Tandem Cyclizations of Tryptamine-Ynamides Yielding 1H-Pyrrolo[2,3-d]carbazole Derivatives
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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.
- Wang, Yanshi,Lin, Jingsheng,Wang, Xiaoyu,Wang, Guanghui,Zhang, Xinhang,Yao, Bo,Zhao, Yuandong,Yu, Pengfei,Lin, Bin,Liu, Yongxiang,Cheng, Maosheng
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supporting information
p. 4026 - 4032
(2018/01/15)
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- Ynesulfonamide-Based Silica Gel and Alumina-Mediated Diastereoselective Cascade Cyclizations to Spiro[indoline-3,3′-pyrrolidin]-2-ones under Neat Conditions
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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.).
- Wang, Yanshi,Wang, Xiaoyu,Lin, Jingsheng,Yao, Bo,Wang, Guanghui,Zhao, Yuandong,Zhang, Xinhang,Lin, Bin,Liu, Yang,Cheng, Maosheng,Liu, Yongxiang
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supporting information
p. 1483 - 1492
(2018/03/01)
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- Synthetic approaches to highly functional -carboline building blocks via allylic amidation
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A new, straightforward synthesis of highly functional -carboline building blocks is presented that makes use of allylic amidation methodology. The products obtained carry a terminal double bond as well as an easy-to-deprotect amide, which make them perfectly suitable for further functionalization. The use of the trifluoroacetamide group is exploited in a dual fashion; it acts as a protecting group and functions as the nucleophile for the allylic amidation reaction. Georg Thieme Verlag Stuttgart New York.
- Teichert, Johannes F.,Fananas-Mastral, Martin,Feringa, Ben L.
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experimental part
p. 409 - 416
(2012/03/11)
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- Facile construction of the pentacyclic framework of subincanadine B. Synthesis of 20-deethylenylated subincanadine B and 19,20-dihydrosubincanadine B
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(Chemical Equation Presented) We describe a facile approach for effectively constructing the pentacyclic framework of subincanadine B. The seven-step assembly of tetracyclic ketone 14 featured Michael addition, Pictet-Spengler cyclization, and Dieckmann condensation. From this key ketone intermediate, two analogues of subincanadine B, i.e., 20-deethylenylated subincanadine B (27) and 19,20-dihydrosubincanadine B (31), were synthesized in four steps, respectively.
- Liu, Yanqin,Luo, Shengjun,Fu, Xingnian,Fang, Fang,Zhuang, Zeyang,Xiong, Wanting,Jia, Xueshun,Zhai, Hongbin
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p. 115 - 118
(2007/10/03)
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- Preparation of novel cyanoguanidine derivatives of tryptamines
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A new class of cyanoguanidine derivatives (5a-s) bearing a tryptamine moiety was prepared in a three-step reaction sequence. The preparation of the starting materials and characterization of the intermediates and products are also described.
- Novak,Hanania,Kovacs,Kolonits,Szantay
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p. 108 - 118
(2007/10/03)
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- Intramolecular inverse electron demand Diels-Alder reactions of tryptamine with tethered heteroaromatic azadienes
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1,2,4,5-Tetrazines and 1,2,4-triazines tethered to tryptamine via the ethylamine side chain undergo intramolecular inverse electron demand cycloadditions to produce adducts with the [ABazaCE]-ring skeleton of the Aspidosperma alkaloids. (C) 2000 Elsevier Science Ltd.
- Benson, Scott C.,Lee, Lily,Yang, Lydie,Snyder, John K.
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p. 1165 - 1180
(2007/10/03)
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- Inverse electron demand Diels-Alder reactions of indole V. Reactions of 3-substituted indoles with heteroaromatic azadienes
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The inverse electron demand Diels-Alder reactions of 3-substituted indoles with 1,2,4-triazines and 1,2,4,5-tetrazines proceeded in excellent yields both inter- and intramolecularly. The cycloaddition of tryptophan with a tethered 1,2,4-triazine produced a diastereomerically pure cycloadduct.
- Benson, Scott C.,Lee, Lily,Snyder, John K.
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p. 5061 - 5064
(2007/10/03)
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- N6-Substituted Adenosine Receptor Agonists. Synthesis and Pharmacological Activity as Potent Antinociceptive Agents
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Novel N6-(indol-3-yl)alkyl derivatives of adenosine were synthesized.The adenosine receptor affinity and the antinociceptive activity of these compounds were assessed in binding studies and the phenylbenzoquinone-induced writhing test.Most of these analogues exhibited a potent analgesic activity without side effects.Among them, compound 3c (UP 202-32) bound to A1 (Ki = 110 nM) and A2 (Ki = 350 nM) adenosine receptors in a specific manner since it did not interact with many other receptors, especially opioid binding sites.The antinociceptive activity in the phenylbenzoquinone assay (ED50 = 3.3 mg/kg po) was antagonized by 8-cyclopentyltheophylline, suggesting that an adenosinergic mechanism underlies the analgesic activity observed with this compound.The data obtained with these new N6-substituted adenosine receptor agonists emphasize the interest of such compounds in the treatment of pain.
- Guengoer, Timur,Malabre, Patrice,Teulon, Jean-Marie,Camborde, Francoise,Meignen, Joelle,et al.
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p. 4307 - 4316
(2007/10/02)
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- A CONVENIENT SYNTHESIS OF TRYPTAMINES
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Reaction of tosylmethyl isocyanide with substituted formyl indoles gave the nitrile with one more carbon atom.Hydrogenation of this nitrile afforded the corresponding tryptamine.
- Merour, J. Y.,Buzas, A.
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p. 2331 - 2336
(2007/10/02)
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