233-34-1Relevant academic research and scientific papers
Pd-Catalyzed Regioselective Direct Double C–H Arylation of 6,7-Benzindoles
Li, Ping-Gui,Yang, Youqing,Zhu, Shuai,Li, Hong-Xi,Zou, Liang-Hua
, p. 73 - 76 (2019)
A palladium-catalyzed protocol for the first direct diarylation of 6,7-benzindoles with aryl iodides at the C4 and C5 positions was developed. The key to this strategy was the employment of pivaloyl as the directing group at the C3 position and the blocking effect at the C6 and C7 positions. The reaction proceeded very well, providing a series of diarylated 6,7-benzindoles without prefunctionalization at the reactive sites. Several examples on the unexpected monoarylation of 6,7-benzindoles at the C5 position were also presented.
Diaryliodonium Salt-Based Synthesis of N-Alkoxyindolines and Further Insights into the Ishikawa Indole Synthesis
Shibata, Kouhei,Takao, Ken-Ichi,Ogura, Akihiro
, p. 10067 - 10087 (2021/07/26)
A diaryliodonium salt-based strategy enabled the first systematic synthesis of rarely accessible N-alkoxyindolines. Mechanistic analyses suggested that the reaction likely involves reductive elimination of iodobenzene from iodaoxazepine via a four-membered transition state, followed by Meisenheimer rearrangement. Substrates with N-carbamate protection afforded indole in a manner similar to that of the Ishikawa indole synthesis. Preinstallation of a stannyl group as an iodonium salt precursor greatly expanded the substrate scope, and further mechanistic insights are discussed.
Phenanthroline- tBuOK Promoted Intramolecular C-H Arylation of Indoles with ArI under Transition-Metal-Free Conditions
Shan, Xiang-Huan,Yang, Bo,Zheng, Hong-Xing,Qu, Jian-Ping,Kang, Yan-Biao
supporting information, p. 7898 - 7901 (2019/01/04)
The first example of phenanthroline-tBuOK promoted intramolecular radical C-H arylation of N-(2-iodobenzyl)indoles without involvement of transition metals has been developed. A variety of substituted 6H-isoindolo [2, 1-a] indoles were prepared by a simple and efficient intramolecular cyclization using 1,10-phenanthroline in the presence of potassium tert-butoxide and chlorobenzene. This strategy provides a fast and versatile access to isoindolo[2,1-a]indole derivatives for the synthesis of pharmaceuticals and organic electroluminescent (EL) materials.
Straight Access to Indoles from Anilines and Ethylene Glycol by Heterogeneous Acceptorless Dehydrogenative Condensation
Llabres-Campaner, Pedro Juan,Ballesteros-Garrido, Rafael,Ballesteros, Rafael,Abarca, Belén
, p. 521 - 526 (2018/01/01)
The development of original strategies for the preparation of indole derivatives is a major goal in drug design. Herein, we report the first straight access to indoles from anilines and ethylene glycol by heterogeneous catalysis, based on an acceptorless dehydrogenative condensation, under noninert conditions. In order to achieve high selectivity, a combination of Pt/Al2O3 and ZnO have been found to slowly dehydrogenate ethylene glycol generating, after condensation with the amine and tautomeric equilibrium, the corresponding pyrrole-ring unsubstituted indoles.
Marbostat-100 Defines a New Class of Potent and Selective Antiinflammatory and Antirheumatic Histone Deacetylase 6 Inhibitors
Sellmer, Andreas,Stangl, Hubert,Beyer, Mandy,Grünstein, Elisabeth,Leonhardt, Michel,Pongratz, Herwig,Eichhorn, Emerich,Elz, Sigurd,Striegl, Birgit,Jenei-Lanzl, Zsuzsa,Dove, Stefan,Straub, Rainer H.,Kr?mer, Oliver H.,Mahboobi, Siavosh
supporting information, p. 3454 - 3477 (2018/05/01)
Epigenetic modifiers of the histone deacetylase (HDAC) family contribute to autoimmunity, cancer, HIV infection, inflammation, and neurodegeneration. Hence, histone deacetylase inhibitors (HDACi), which alter protein acetylation, gene expression patterns, and cell fate decisions, represent promising new drugs for the therapy of these diseases. Whereas pan-HDACi inhibit all 11 Zn2+-dependent histone deacetylases (HDACs) and cause a broad spectrum of side effects, specific inhibitors of histone deacetylase 6 (HDAC6i) are supposed to have less side effects. We present the synthesis and biological evaluation of Marbostats, novel HDAC6i that contain the hydroxamic acid moiety linked to tetrahydro-β-carboline derivatives. Our lead compound Marbostat-100 is a more potent and more selective HDAC6i than previously established well-characterized compounds in vitro as well as in cells. Moreover, Marbostat-100 is well tolerated by mice and effective against collagen type II induced arthritis. Thus, Marbostat-100 represents a most selective known HDAC6i and the possibility for clinical evaluation of a HDAC isoform-specific drug.
Palladium/Phosphorus-Doped Porous Organic Polymer as Recyclable Chemoselective and Efficient Hydrogenation Catalyst under Ambient Conditions
Ding, Zong-Cang,Li, Cun-Yao,Chen, Jun-Jia,Zeng, Jia-Hao,Tang, Hai-Tao,Ding, Yun-Jie,Zhan, Zhuang-Ping
, p. 2280 - 2287 (2017/07/07)
A new type of phosphorus-doped porous organic polymer (POP) has been readily synthesized through a Heck reaction, which could be used not only as a support but also a ligand for palladium nanoparticles. The dual-functional material supported palladium nanocatalyst was used for the efficient and chemoselective hydrogenation of varieties of nitroarenes and α,β-unsaturated compounds, as well as for the synthesis of indoles from 2-nitrophenylacetonitrile under 1 atm hydrogen in green solvents at room temperature. No obvious aggregation and loss of catalytic activity of the new nanocatalyst were observed after 10 runs in the reaction. (Figure presented.).
Active and Recyclable Catalytic Synthesis of Indoles by Reductive Cyclization of 2-(2-Nitroaryl)acetonitriles in the Presence of Co-Rh Heterobimetallic Nanoparticles with Atmospheric Hydrogen under Mild Conditions
Choi, Isaac,Chung, Hyunho,Park, Jang Won,Chung, Young Keun
, p. 5508 - 5511 (2016/11/17)
A cobalt-rhodium heterobimetallic nanoparticle-catalyzed reductive cyclization of 2-(2-nitroaryl)acetonitriles to indoles has been achieved. The tandem reaction proceeds without any additives under the mild conditions (1 atm H2 and 25 °C). This procedure could be scaled up to the gram scale. The catalytic system is significantly stable under these reaction conditions and could be reused more than ten times without loss of catalytic activity.
A combined experimental and computational study on the cycloisomerization of 2-ethynylbiaryls catalyzed by dicationic arene ruthenium complexes
Yamamoto, Yoshihiko,Matsui, Kazuma,Shibuya, Masatoshi
supporting information, p. 7245 - 7255 (2015/05/05)
Ruthenium-catalyzed cycloisomerization of 2-ethynylbiaryls was investigated to identify an optimal ruthenium catalyst system. A combination of [η6-(p-cymene)RuCl2(PR3)] and two equivalents of AgPF6 effectively converted 2-ethynylbiphenyls into phenanthrenes in chlorobenzene at 120 °C over 20 h. Moreover, 2-ethynylheterobiaryls were found to be favorable substrates for this ruthenium catalysis, thus achieving the cycloisomerization of previously unused heterocyclic substrates. Moreover, several control experiments and DFT calculations of model complexes were performed to propose a plausible reaction mechanism.
N-Heterocyclization of naphthylamines with 1,2- And 1,3-Diols catalyzed by an iridium Chloride/BINAP system
Aramoto, Hiroomi,Obora, Yasushi,Ishii, Yasutaka
scheme or table, p. 628 - 633 (2009/06/28)
Benzoquinoline derivatives were successfully synthesized by iridium-catalyzed N-heterocyclization of naphthylamines with diols. For instance, the reaction of 1-naphthylamine with 1,3-propanediol catalyzed by IrCl3 combined with BINAP as a ligand produced 7,8-benzoquinoline in quantitative yield. The VV-heterocyclization reaction was found to be markedly influenced by the ligands employed. Benzoindoles were also synthesized by the same strategy from napthylamines with 1,2-diols. A reaction mechanism for the N-heterocyclization of naphthylamines with 1,3-diols by IrCl3 was proposed.
A peculiar selective rearrangement during the NiS-catalysed dehydrogenation of 4,5-dihydro-1H-benz[g]indole
Trofimov, Boris A.,Vasil'tsov, Alexander M.,Ushakov, Igor' A.,Ivanov, Andrey V.,Schmidt, Elena Yu.,Mikhaleva, Al'bina I.,Protsuk, Nadezhda I.,Kobychev, Vladimir B.
, p. 296 - 298 (2008/03/12)
The dehydrogenation of 4,5-dihydro-1H-benz[g]indole on NiS/Al2O3 (350 °C) is accompanied by a peculiar rearrangement to give 3H-benz[e]indole (71%).
