- Synthesis of Polysubstituted Fused Pyrroles by Gold-Catalyzed Cycloisomerization/1,2-Sulfonyl Migration of Yndiamides
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Yndiamides (bis-N-substituted alkynes) are valuable precursors to azacycles. Here we report a cycloisomerization/1,2-sulfonyl migration of alkynyl-yndiamides to form tetrahydropyrrolopyrroles, unprecedented heterocyclic scaffolds that are relevant to medicinal chemistry. This functional group tolerant transformation can be achieved using Au(I) catalysis that proceeds at ambient temperature, and a thermally promoted process. The utility of the products is demonstrated by a range of reactions to functionalize the fused pyrrole core.
- Smith, Philip J.,Jiang, Yubo,Tong, Zixuan,Pickford, Helena D.,Christensen, Kirsten E.,Nugent, Jeremy,Anderson, Edward A.
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supporting information
p. 6547 - 6552
(2021/08/30)
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- Synthesis of palladated magnetic nanoparticle (Pd@Fe3O4/AMOCAA) as an efficient and heterogeneous catalyst for promoting Suzuki and Sonogashira cross-coupling reactions
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Palladium supported magnetic nanoparticle (Pd@Fe3O4/AMOCAA) was easily prepared in the presence of Scrophularia striata extract and fully characterized by FT-IR, SEM, VSM, TEM, TGA, XRD and EDAX. It was successfully employed as an easily separable and reusable effective heterogeneous catalyst classical Suzuki and Sonogashira cross-coupling reaction. Sustainability of the methodology was reserved by easy recovery of the catalyst using an external magnet and reusing it for 7 times without appreciable loss of its catalytic activity.
- Tamoradi, Taiebeh,Daraie, Mansoureh,Heravi, Majid M.
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- External Oxidant-Free Oxidative Tandem Cyclization: NaI-Catalyzed Thiolation for the Synthesis of 3-Thiosubstituted Pyrroles
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A simple method for the synthesis of 3-thiosubstituted pyrroles from homopropargylic amines and thiosulfonates via a tandem sulfenylation/cyclization has been developed. The thiosulfonates are used both as substrates and oxidants in this transformation. This procedure exhibits good functional group tolerance and a series of 3-thiosubstituted pyrrole derivatives was obtained in moderate to good yields. (Figure presented.).
- Yuan, Bingxiang,Jiang, Yong,Qi, Zhenjie,Guan, Xin,Wang, Ting,Yan, Rulong
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supporting information
p. 5112 - 5117
(2019/11/11)
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- Tert-Butyl Nitrite Promoted Oxidative Intermolecular Sulfonamination of Alkynes to Synthesize Substituted Sulfonyl Pyrroles from the Alkynylamines and Sulfinic Acids
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tert-Butyl nitrite promoted oxidative intermolecular sulfonamination of alkynes to synthesize substituted sulfonyl pyrroles from the alkynylamines and sulfinic acids via tandem addition/cyclization was developed. This reaction is performed well by employing tert-butyl nitrite as the oxidant, and various substituted sulfonyl pyrroles are formed in moderate to good yields with no requirement of metal catalysis.
- Qi, Zhenjie,Jiang, Yong,Wang, Yanyan,Yan, Rulong
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supporting information
p. 8636 - 8644
(2018/06/18)
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- Cu-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of 3,3′-Bipyrroles from the Homopropargylic Amines
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A Cu-catalyzed method for the synthesis of 3,3′-bipyrroles from homopropargylic amines through tandem aerobic oxidative cyclization involving the formation of C-C bond has been developed. The features of this reaction are a small number of Cu catalysis and simple starting substrates. Moreover, this procedure exhibits good functional group tolerance and a series of 3,3′-bipyrroles derivatives are obtained in moderate to good yields.
- Qi, Zhenjie,Jiang, Yong,Yuan, Bingxiang,Niu, Yanning,Yan, Rulong
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supporting information
p. 5048 - 5052
(2018/08/24)
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- Asymmetric Synthesis of Fused Bicyclic N,O- and O,O-Acetals via Cascade Reaction by Gold(I)/N,N′-Dioxide-Nickel(II) Bimetallic Relay Catalysis
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An efficient catalytic asymmetric cyclization/inverse-electron-demand hetero-Diels-Alder cascade reaction of β,γ-unsaturated α-ketoesters with alkyl amides or alcohols were accomplished. The process was based on the utilization bimetallic catalyst system with achiral gold(I) catalyst and chiral N,N′-dioxide/Ni(II) catalyst, delivering a variety of fused bicyclic N,O-acetals or O,O-acetals in up to 99% yield and 99% ee with >19:1 dr under mild reaction conditions. Based on the control experiments and previous studies, a possible reaction pathway of bimetallic relay catalysis cascade reactions was presented. (Figure presented.).
- Hu, Bowen,Li, Jun,Cao, Weidi,Lin, Qianchi,Yang, Jian,Lin, Lili,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 2831 - 2835
(2018/08/17)
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- Targeting an Aromatic Hotspot in Plasmodium falciparum 1-Deoxy-d-xylulose-5-phosphate Reductoisomerase with β-Arylpropyl Analogues of Fosmidomycin
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Blocking the 2-C-methyl-d-erythrithol-4-phosphate pathway for isoprenoid biosynthesis offers new ways to inhibit the growth of Plasmodium spp. Fosmidomycin [(3-(N-hydroxyformamido)propyl)phosphonic acid, 1] and its acetyl homologue FR-900098 [(3-(N-hydroxyacetamido)propyl)phosphonic acid, 2] potently inhibit 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr), a key enzyme in this biosynthetic pathway. Arylpropyl substituents were introduced at the β-position of the hydroxamate analogue of 2 to study changes in lipophilicity, as well as electronic and steric properties. The potency of several new compounds on the P. falciparum enzyme approaches that of 1 and 2. Activities against the enzyme and parasite correlate well, supporting the mode of action. Seven X-ray structures show that all of the new arylpropyl substituents displace a key tryptophan residue of the active-site flap, which had made favorable interactions with 1 and 2. Plasticity of the flap allows substituents to be accommodated in many ways; in most cases, the flap is largely disordered. Compounds can be separated into two classes based on whether the substituent on the aromatic ring is at the meta or para position. Generally, meta-substituted compounds are better inhibitors, and in both classes, smaller size is linked to better potency.
- Sooriyaarachchi, Sanjeewani,Chofor, René,Risseeuw, Martijn D. P.,Bergfors, Terese,Pouyez, Jenny,Dowd, Cynthia S.,Maes, Louis,Wouters, Johan,Jones, T. Alwyn,Van Calenbergh, Serge,Mowbray, Sherry L.
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p. 2024 - 2036
(2016/10/22)
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- A Simple and Efficient Palladium Catalyst of Nitrogen-Based Ligand for Cu(I)- and Amine-Free Sonogashira Reaction
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Glycine, as a kind of commercially available and inexpensive ligand, is used to prepare an air-stable and water-soluble catalyst used in Sonogashira reaction in our study. In the presence of 1% [PdCl2(NH2CH2COOH)2/su
- Guo, Meng-Ping,Liu, Shi-Wen,Chen, San-Bao,Wen, Yong-Ju,Liang, Hui,Lv, Mei-Yun
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supporting information
p. 777 - 787
(2015/10/29)
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- Rhodium(III)-catalyzed oxidative bicyclization of 4-arylbut-3-yn-1-amines with internal alkynes through C-H functionalization
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A new Rh(III)-catalyzed oxidative bicyclization through C-H functionalization is presented. This reaction allows the selective assembly of diverse benzo[g]indoles from 4-arylbut-3-yn-1-amines and internal alkynes via a sequence of aromatic C(sp2)-H functionalization, cyclodimerization and nucleophilic cyclization.
- Pi, Rui,Zhou, Ming-Bo,Yang, Yuan,Gao, Cai,Song, Ren-Jie,Li, Jin-Heng
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supporting information
p. 13550 - 13553
(2015/09/01)
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- Gold and palladium combined for the Sonogashira coupling of aryl and heteroaryl halides
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A highly efficient gold and palladium combined methodology for the Sonogashira coupling of a wide array of electronically and structurally diverse aryl and heteroaryl halides is described. The orthogonal reactivity of the two metals shows high selectivity and extreme functional group tolerance in Sonogashira coupling. A brief mechanistic study reveals that the gold acetylide intermediate enters into the palladium catalytic cycle at the transmetalation step. Georg Thieme Verlag Stuttgart.New York.
- Panda, Biswajit,Sarkar, Tarunk.
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p. 817 - 829
(2013/04/10)
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- Synthesis of propargylic and allenic carbamates via the C-H amination of alkynes
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Propargylic amines are important intermediates for the synthesis of nitrogen-containing heterocycles. The insertion of a nitrene into a propargylic C-H bond has not been explored, despite the attention directed toward the Rh-catalyzed amination of other t
- Grigg, R. David,Rigoli, Jared W.,Pearce, Simon D.,Schomaker, Jennifer M.
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supporting information; experimental part
p. 280 - 283
(2012/02/16)
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- N-Heterocyclic carbene-catalyzed 1,3-dipolar cycloaddition reactions: A facile synthesis of 3,5-di- and 3,4,5-trisubstituted isoxazoles
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A first example of organo-N-heterocyclic carbene (NHC) catalyzed click-type fast 1,3-dipolar cycloaddition of nitrile oxides with alkynes was developed for the regioselective synthesis of 3,5-di- and 3,4,5-trisubstituted isoxazoles. Triethylamine (Et
- Kankala, Shravankumar,Vadde, Ravinder,Vasam, Chandra Sekhar
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experimental part
p. 7869 - 7876
(2011/12/05)
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- Gold and palladium combined for the Sonogashira-type cross-coupling of arenediazonium salts
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The Sonogashira-type cross-coupling of arenediazonium salts is reported for the first time using a Pd-Au dual catalytic system. The Royal Society of Chemistry 2010.
- Panda, Biswajit,Sarkar, Tarun K.
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scheme or table
p. 3131 - 3133
(2010/08/20)
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- On the catalytic duo PdCl2(PPh3)2/AuCl(PPh3) that cannot effect a Sonogashira-type reaction: a correction
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In contrast to the observation made by the Laguna group, we report that the combination of PdCl2(PPh3)2 and AuCl(PPh3) makes a unique catalytic system that allows Sonogashira-type cross-coupling of both aryl and alkyl alkynes with aryl halides in excellent yields.
- Panda, Biswajit,Sarkar, Tarun K.
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experimental part
p. 301 - 305
(2010/03/26)
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- Gold-catalyzed tandem cycloisomerization-hydroalkoxylation of homopropargylic alcohols
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The tandem cycloisomerization-hydroalkoxylation of various homopropargylic alcohols in the presence of an alcohol and a dual catalyst system, consisting of a gold precatalyst and a Bronsted acid, provides an efficient route to tetrahydrofuranyl ethers und
- Belting, Volker,Krause, Norbert
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p. 4489 - 4492
(2007/10/03)
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- Aqueous-phase, palladium-catalyzed cross-coupling of aryl bromides under mild conditions, using water-soluble, sterically demanding alkylphosphines
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Sterically demanding, water-soluble alkylphosphines have been used in combination with various palladium salts in Suzuki, Sonogashira, and Heck couplings of aryl bromides under mild conditions in aqueous solvents. The tert-butyl-substituted ligands 2-(di-tert-butylphosphino)ethyltrimethylammonium chloride (t-Bu-Amphos) and 4-(di-tert-butylphosphino)-N,N-dimethylpiperidinium chloride (t-Bu-Pip-phos) in combination with palladium(II) salts were found to give catalysts that were significantly more active than catalysts derived from tri(3-sulfonatophenyl)phosphine trisodium (TPPTS). Suzuki couplings of unactivated aryl bromides occurred efficiently at room temperature in water/acetonitrile and water/toluene biphasic mixtures or in neat water. Notably, Suzuki couplings of hydrophilic aryl bromides gave high yields without using organic solvents for the reaction or purification. This methodology has been applied to a highly efficient synthesis of diflunisal. The catalyst derived from t-Bu-Amphos was recycled three times in Suzuki couplings in water/toluene before catalyst activity began to significantly drop. The average yield of four cycles was >80% per cycle. Heck and Sonogashira couplings were carried out under mild conditions (50 and 80°C, respectively) with unactivated aryl bromides to give coupled products in high yield.
- DeVasher, Rebecca B.,Moore, Lucas R.,Shaughnessy, Kevin H.
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p. 7919 - 7927
(2007/10/03)
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- Sonogashira coupling of aryl halides catalyzed by palladium on charcoal
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With the proper choice of solvent, palladium on charcoal acts as an efficient catalyst in the Sonogashira cross-coupling reaction of aryl bromides. The catalytically active species in the process is probably palladium, which leaches into the solution but
- Novak, Zoltan,Szabo, Andras,Repasi, Jozsef,Kotschy, Andras
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p. 3327 - 3329
(2007/10/03)
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- Regioselective synthesis of 4-substituted-1-aryl-1-butanones using a Sonogashira-hydration strategy: Copper-free palladium-catalyzed reaction of terminal alkynes with aryl bromides
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A simple one-pot procedure has been developed for the synthesis of 4-substituted-1-aryl-1-butanones through copper-free Sonogashira reaction of aryl bromides with terminal alkynes in DMF under inert atmosphere, followed by the treatment with acid in the p
- Pal, Manojit,Parasuraman, Karuppasamy,Gupta, Shalabh,Yeleswarapu, Koteswar Rao
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p. 1976 - 1982
(2007/10/03)
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- Vinyl Cations. 41. Influence of 4-Aryl and 4-Alkyl Substituents on the ?-Route Solvolyses of Homopropargyl Esters
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The four 4-substituted-homopropargyl tosylates and triflates 6b-e (R=phenyl, p-tolyl, anisyl, and cyclopropyl) have been synthesized and solvolyzed under various conditions, as have 2-cyclopropyl-1-cyclobutenyl triflate (11-OTf) and nonaflate (11-ONf).In addition, the solvolyses of pent-3-yn-1-yl tosylate (6a-OTs, R=methyl) and triflate (prepared previously) are reported.The ratios of C-3 ring to C-4 ring 3 ring/C4ring)> products are recorded for the reactions in various solvents.As expected, ring closure (kΔ) increases and solvent displacement (kS, SN2) decreases with decreasing nucleophilicity of solvent.Temperature effects are noted for the sovolyses of tosylates 6a-e in 100percent TFE buffered with Na2CO3 in which kΔ increases with increasing temperature.The result is explained by decomposition of the intimate ion pair with temperature, whereupon elimination to the enyne becomes smaller and ring closure (kΔ) increases at the expense of elimination.The possibility of intervention of nonclassical vinyl cations is discussed, as are other mechanistic implications.
- Collins, Clair J.,Hanack, Michael,Stutz, Herbert,Auchter, Gerhard,Schoberth, Winfried
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p. 5260 - 5268
(2007/10/02)
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