- Synthesis of functionalized indoles via palladium-catalyzed cyclization of N-(2-allylphenyl) benzamide: A method for synthesis of indomethacin precursor
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We developed an efficient method for synthesis of substituted N-benzoylindole via Pd(II)-catalyzed C-H functionalization of substituted N-(2-allylphenyl)benzamide. The reaction showed a broad substrate scope (including N-acetyl and N-Ts substrates) and substituted indoles were obtained in good to excellent yields. The most distinctive feature of this method lies in the high selectivity for N-benzoylindole over benzoxazine, and this is the first example of Pd(II)-catalyzed synthesis of substituted N-benzoylindole. Notably, this new method was applied for the synthesis of key intermediate of indomethacin.
- Chang, Zhe,Dong, Zheng,Ma, Tong,Zhang, Yu,Zhao, Depeng,Zhao, Heng
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- Synthesis of Benzofuran and Indole Derivatives Catalyzed by Palladium on Carbon
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Benzofurans and indoles are key moieties in many natural products and pharmaceuticals. Herein, we describe a cheap and easy-to-execute strategy for the synthesis of benzofurans and indoles, employing Pd/C as the promoter. A variety of substituted allyl-anilines and allyl-phenols were converted into the desired products in good to excellent yields. Recycling of Pd/C was possible up to five cycles, keeping similar levels of reactivity.
- Savvidou, Anatoli,IoannisTzaras, Dimitrios,Koutoulogenis, Giorgos S.,Theodorou, Alexis,Kokotos, Christoforos G.
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p. 3890 - 3897
(2019/06/27)
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- One-pot Construction of Difluorinated Pyrrolizidine and Indolizidine Scaffolds via Copper-Catalyzed Radical Cascade Annulation
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A convenient approach to the synthesis of diverse difluorinated nitrogen-containing polycycles via a copper-catalyzed radical cascade annulation of amine-containing olefins and ethyl bromodifluoroacetate was developed. Three new bonds, including a Csp3 ?CF2 and two C?N bonds, are forged simultaneously in this strategy. Through this strategy, a series of difluorinated pyrrolizidine and indolizidine derivatives have been conveniently synthesized in good yields. (Figure presented.).
- Wang, Xiaoyang,Li, Miao,Yang, Yanyan,Guo, Minjie,Tang, Xiangyang,Wang, Guangwei
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p. 2151 - 2156
(2018/04/26)
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- Palladium-Catalyzed Fluoroalkylative Cyclization of Olefins
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A palladium-catalyzed fluoroalkylative cyclization of olefins with readily available Rf-I reagents to afford the corresponding fluoroalkylated 2,3-dihydrobenzofuran and indolin derivatives with moderate to excellent yields is reported. This novel procedure provides an efficient method for the construction of Csp3-CF2 and C-O/N bonds in one step. A wide range of functional groups are tolerated. It is proposed that a radical/SET (single electron transfer) pathway proceeding via the fluoroalkyl radical may be involved in the catalytic cycle.
- Liao, Jianhua,Fan, Lianfeng,Guo, Wei,Zhang, Zhenming,Li, Jiawei,Zhu, Chuanle,Ren, Yanwei,Wu, Wanqing,Jiang, Huanfeng
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p. 1008 - 1011
(2017/03/15)
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- Green Organocatalytic Synthesis of Indolines and Pyrrolidines from Alkenes
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Employing a green and efficient 2,2,2-trifluoroacetophenone-catalyzed oxidation of alkenes, which utilizes H2O2 as the green oxidant, a novel and sustainable synthesis of indolines and pyrrolidines was developed. This constitutes a cheap, general and environmentally-friendly protocol for the synthesis of substituted nitrogen-containing heterocycles. A variety of substitution patterns, both aromatic and aliphatic moieties, are well tolerated leading to the desired nitrogen heterocycles in good to excellent yields. (Figure presented.).
- Theodorou, Alexis,Kokotos, Christoforos G.
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p. 1577 - 1581
(2017/05/05)
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- Thioamination of Alkenes with Hypervalent Iodine Reagents
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An efficient thioamination of alkenes mediated by iodine(III) reagents is described. The use of different sulfur nucleophiles allows the flexible synthesis of 1,2-aminothiols from alkenes. By employing chiral iodine(III) reagents, a stereoselective version of the thioamination protocol has also been developed.
- Mizar, Pushpak,Niebuhr, Rebecca,Hutchings, Matthew,Farooq, Umar,Wirth, Thomas
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p. 1614 - 1617
(2016/02/20)
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- Palladium-Catalyzed Aerobic Intramolecular Aminoacetoxylation of Alkenes Enabled by Catalytic Nitrate
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A mild aerobic intramolecular aminoacetoxylation method for the synthesis of pyrrolidine and indoline derivatives was achieved using molecular oxygen as the oxidant. A catalytic NOx species acts as an electron transfer mediator to access a high-valent palladium intermediate as the presumed active oxidant.
- Li, Jiaming,Grubbs, Robert H.,Stoltz, Brian M.
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p. 5449 - 5451
(2016/11/17)
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- Copper-catalyzed radical cascade cyclization for the synthesis of phosphorated indolines
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A novel and convenient approach to the synthesis of various phosphorated indolines via a copper-catalyzed radical cascade cyclization reaction has been developed. The reaction employs cheap copper as the catalyst and K2S2O8 as the oxidant under mild conditions. Various alkenes and P-radical precursors are compatible with this transformation. Preliminary mechanistic studies reveal that the addition of the P-radical may initiate the reaction, and then oxidative cyclization may be achieved to afford the desired product. This journal is
- Zhang, Hong-Yu,Mao, Liu-Liang,Yang, Bin,Yang, Shang-Dong
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p. 4101 - 4104
(2015/03/30)
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- M-CPBA-Mediated Intramolecular Aminohydroxylation of N-Sulfonyl Aminoalkenes to Synthesize β-Hydroxyl Cyclic Amines
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A variety of structurally diverse N-sulfonyl-protected aminoalkenes readily reacted with m-CPBA to produce a series of β-hydroxyl cyclic amines in high yields through intramolecular aminohydroxylation. This metal-free and easy-to-handle synthetic methodol
- Yin, Yan,Zhou, Hong,Sun, Guofeng,Liu, Xichen
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p. 1337 - 1345
(2015/10/06)
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- Efficient copper-catalyzed direct intramolecular aminotrifluoromethylation of unactivated alkenes with diverse nitrogen-based nucleophiles
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A mild, convenient, and step-economical intramolecular aminotrifluoromethylation of unactivated alkenes with a variety of electronically distinct, nitrogen-based nucleophiles in the presence of a simple copper salt catalyst, in the absence of extra ligand
- Lin, Jin-Shun,Xiong, Ya-Ping,Ma, Can-Liang,Zhao, Li-Jiao,Tan, Bin,Liu, Xin-Yuan
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p. 1332 - 1340
(2014/04/03)
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- Synthesis of novel [3,1]-benzothiazepine and [3,1]-benzoxazepine derivatives with antitumoral activity
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A new method for the synthesis of [3,1]-benzothiazepines and [3,1]-benzoxazepines from the reaction of C-allylanilines and isothiocyanates or isocyanates without the need for the isolation of any intermediate is described. The compounds were obtained in good to moderate yields and some exhibited cytotoxic activity against tumor cell lines. This journal is the Partner Organisations 2014.
- Martinez, Walter R.,Militao, Gardenia C. G.,Da Silva, Teresinha G.,Silva, Ricardo O.,Menezes, Paulo H.
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p. 14715 - 14718
(2014/04/17)
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- Palladium-catalyzed selective aminoamidation and aminocyanation of alkenes using isonitrile as amide and cyanide sources
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A mild and efficient palladium-catalyzed intermolecular aminoamidation and aminocyanation reaction of alkenes with a broad substrate scope has been developed. This cyclization process provides a valuable synthetic tool for obtaining substituted indolines, tetrahydroisoquinolines and pyrrolidines in good to excellent yields. This journal is
- Jiang, Huanfeng,Gao, Hanling,Liu, Bifu,Wu, Wanqing
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p. 15348 - 15351
(2015/01/08)
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- Organocatalytic Stereoselective Iodoamination of Alkenes
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A new chiral thiohydantoin catalyst is used for the stereoselective iodoamination of alkenes. N-iodosuccinimide as the source of the electrophilic iodine is activated by catalytic amounts of different additives which also influence the regioselectivity of some cyclizations.
- Mizar, Pushpak,Burrelli, Alessandra,Günther, Erika,S?ftje, Martin,Farooq, Umar,Wirth, Thomas
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p. 13113 - 13116
(2016/02/19)
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- Asymmetric indoline synthesis via intramolecular aza-Michael addition mediated by bifunctional organocatalysts
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A novel method for the asymmetric synthesis of 2-substituted indolines, employing bifunctional amino(thio)urea catalysts, was developed. The reaction proceeded via an intramolecular aza-Michael addition mediated by activation through hydrogen bonding. The
- Miyaji, Ryota,Asano, Keisuke,Matsubara, Seijiro
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supporting information
p. 3658 - 3661
(2013/08/23)
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- Copper-catalyzed enantioselective intramolecular alkene amination/intermolecular heck-type coupling cascade
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Enantioselective copper-catalyzed cyclization of γ- alkenylsulfonamides and a δ-alkenylsulfonamide in the presence of a range of vinyl arenes results in variously functionalized 2-substituted chiral nitrogen heterocycles via a formal alkene C-H functionalization process. Application of this reaction to the concise synthesis of a 5-HT7 receptor antagonist is demonstrated.
- Liwosz, Timothy W.,Chemler, Sherry R.
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p. 2020 - 2023
(2012/03/12)
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- Catalytic enantioselective alkene aminohalogenation/cyclization involving atom transfer
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Problem solved: The title reaction was used for the synthesis of chiral 2-bromo, chloro, and iodomethyl indolines and 2-iodomethyl pyrrolidines (see scheme). Stereocenter formation is believed to occur by enantioselective cis aminocupration and C-X bond formation is believed to occur by atom transfer. The ultility of the products as versatile synthetic intermediates was demonstrated, as was a radical cascade cyclization sequence. Copyright
- Bovino, Michael T.,Chemler, Sherry R.
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p. 3923 - 3927
(2012/05/20)
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- A new entry to the phenanthridine ring system
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A new synthesis of phenanthridine derivatives having three-point diversity has been developed based on the sequential application of three-atom economic processes viz. aza-Claisen rearrangement, ring-closing enyne metathesis and Diels-Alder reaction as key steps. An unexpected isomerisation was observed during aza-Claisen rearrangement of N-allylanilines which may open up new opportunities in heterocyclic synthesis.
- Mondal, Poulomi,Thander, Latibuddin,Chattopadhyay, Shital K.
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p. 1328 - 1331
(2012/04/04)
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- Synthesis of nitrogen-containing heterocycles via ring-closing ene-ene and ene-yne metathesis reactions: An easy access to 1- and 2-benzazepine scaffolds and five- and six-membered lactams
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Novel regioselective ring closing ene-yne metathesis provided an efficient access to different substituted 1-benzazepine scaffolds. The reported synthetic approach could also be used as a powerful tool for the selective formation of a highly functionaliza
- Benedetti, Erica,Lomazzi, Michela,Tibiletti, Francesco,Palmisano, Giovanni,Penoni, Andrea,Goddard, Jean-Philippe,Fensterbank, Louis,Malacria, Max
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supporting information
p. 3523 - 3533,11
(2012/12/12)
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- Stereoselective synthesis of novel 2-alkenyl-2,3,4,5-tetrahydro-1,4-epoxy- 1-benzazepines and 2-alkenyl-2,3,4,5-tetrahydro-1H-1-benzazepin-4-ols
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New series of polyfunctionalized 2,3,4,5-tetrahydro-1,4-epoxy-1- benzazepines and 2,3,4,5-tetrahydro-1H-1-benzazepin-4-ols substituted at C2 with 2-methylprop-1-enyl, (E)-styryl, and (E)-pent-1-enyl were synthesized starting from the corresponding N-alken
- Acosta Quintero, Lina María,Palma, Alirio,Nogueras, Manuel,Cobo, Justo
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p. 3765 - 3782
(2013/02/23)
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- Sequential combination of ruthenium-, base-, and gold-catalysis - A new approach to the synthesis of medicinally important heterocycles
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A general approach to the high-yielding synthesis of medicinally important heterocycles was achieved through the sequential combination of ring-closing metathesis, base-induced ring opening (BIRO), hydroamination, and a Diels-Alder reaction of functionalized allyl-(2-allylphenyl)amines in the presence of a catalytic amount of Grubbs' second-generation catalyst, base (tBuOK), and [AuCl(PPh3)]/AgOTf. Herein, we also demonstrate the important electronic factors in the BIRO of N-substituted-benzo[b]azepines for the regioselective synthesis of functionalized (Z)-N-substituted-2-(buta-1,3-dienyl) phenylamines in very good yields with high purity; these are very good, useful compounds in medicinal chemistry. We also discovered the selective cascade synthesis of privileged hexahydrophenanthridines from (Z)-N-substituted-2-(buta- 1,3-dienyl)phenylamines by gold catalysis in moderate to good yields with >99 % diastereomeric excess. The possible reaction mechanism for the unusual hydroamination followed by [4+2] cycloaddition of functionalized (Z)-N-substituted-2-(buta-1,3-dienyl)phenylamines through gold catalysis is discussed in this work. A novel process for the synthesis of highly substituted, medicinally important heterocycles was achieved through the sequential combination of ring-closing methathesis, base-induced ring opening, hydroamination, and Diels-Alder reaction of functionalized allyl-(2-allylphenyl) amines in the presence of a catalytic amount of [Ru], base, and [Au] (see scheme). Copyright
- Ramachary, Dhevalapally B.,Narayana, Vidadala V.
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supporting information; experimental part
p. 3514 - 3522
(2011/08/06)
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- Palladium(II)-catalyzed oxidative cascade cyclization reactions of anilides and anilines: Scope and mechanistic investigations
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With Pd(OAc)2/pyridine as the catalyst system and molecular oxygen as a green oxidant, acrylanilides and N-allylanilines undergo oxidative cascade cyclization to form heterocyclic rings in high yields. This methodology is applicable to acrylani
- Yip, Kai-Tai,Yang, Dan
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supporting information; scheme or table
p. 2166 - 2175
(2011/10/12)
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- Highly stereoselective 7-endo-trig /ring contraction cascade to construct pyrrolo[1,2- a ]quinoline derivatives
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With the cooperation of Cram's phenonium ion, a novel cascade reaction was illustrated to construct pyrrolo[1,2-a]quinolines as a sole diastereoisomer in good to excellent yields. Preliminary mechanistic studies revealed that the γ-lactam ring and electron-rich arene are important driving forces for ring contraction.
- Li, Xinyu,Li, Cheng,Zhang, Wenjing,Lu, Xiang,Han, Shiqing,Hong, Ran
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supporting information; experimental part
p. 1696 - 1699
(2010/09/05)
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- Rational use of substituted N-allyl and N,N-diallylanilines in the stereoselective synthesis of novel 2-alkenyltetrahydro-1-benzazepines
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Two new series of 1,4-epoxy-2-exo-vinyl(isopropenyl)tetrahydro-1- benzazepines and cis-2-vinyl(isopropenyl)-4-hydroxytetrahydro-1-benzazepines were prepared by an efficient three/four-step route from available substituted N,N-diallylanilines and mono N-al
- Acosta, Lina María,Palma, Alirio,Bahsas, Alí
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experimental part
p. 8392 - 8401
(2010/11/19)
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- Efficient regio- And stereoselective formation of azocan-2-ones via 8-endo cyclization of α-carbamoyl radicals
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The iodine-atom-transfer 8-endo cyclization of α-carbamoyl radicals was investigated experimentally and theoretically. With the aid of Mg(CIO 4)2 and a bis(oxazoline) ligand, N- ethoxycarbonylsubstituted N-(pent-4-enyl)-2-iodoalkanamides underwent 8-endo cyclization leading to the formation of only the corresponding 3,5-trans-substituted azocan-2-ones in excellent yields. Similarly, the BF 3·OEt2/H2O-promoted reactions of N-ethoxycarbonyl-N-(2-allylaryl)-2-iodoalkanamides afforded exclusively the benzazocanone products with a 3,5-cis configuration in high yields. The bidentate chelation of substrate radicals not only significantly improved the efficiency of cyclization but also resulted in the change of stereochemistry of azocanone products from 3,8-iransto 3,8-cis. Theoretical calculations at the UB3LYP/6-31G* level revealed that the cyclization of N-carbonyl- substituted α-carbamoyl radicals occurs via the E-conformational transition states without the presence of a Lewis acid. On the other hand, the cyclization proceeds via the Z-conformational transition states when the substrates form the bidentate chelation with a Lewis acid. In both cases, the 8-endo cyclization is always fundamentally preferred over the corresponding 7-exo cyclization. The complexed radicals having the more rigid conformations also allow the better stereochemical control in the iodine-atom-abstraction step. To further understand the reactivity of a-carbamoyl radicals, the competition between the 8-endo and 5-exo cyclization was also studied. The results demonstrated that the 8-endo cyclization is of comparable rate to the corresponding 5-exo cyclization for a-carbamoyl radicals with fixed Z-conformational transition states. As a comparison, the 8-endo mode is fundamentally preferred over the 5-exo mode in the cyclization of NH-amide substrates because the latter requires the Z-conformational transition states, whereas the former proceeds via the more stable E-conformational transition states.
- Fang, Xinqiang,Liu, Kun,Li, Chaozhong
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supporting information; experimental part
p. 2274 - 2283
(2010/05/01)
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- Synthesis, structural elucidation and in vitro antiparasitic activity against Trypanosoma cruzi and Leishmania chagasi parasites of novel tetrahydro-1-benzazepine derivatives
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Forty six new 1,4-epoxy-2-exo-aryl- and cis-2-aryl-4-hydroxytetrahydro-1- benzazepine derivatives were synthesized and fully characterized. All compounds were tested in vitro against both Trypanosoma cruzi and Leishmania chagasi parasites and also for cyt
- Gomez-Ayala, Sandra,Castrillon, Julian A.,Palma, Alirio,Leal, Sandra M.,Escobar, Patricia,Bahsas, Ali
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scheme or table
p. 4721 - 4739
(2010/08/22)
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- Oxidative diamination of alkenes with ureas as nitrogen sources: Mechanistic pathways in the presence of a high oxidation state palladium catalyst
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A first palladium-catalyzed intramolecular diamination of unfunctionalized terminal alkenes has recently been reported. This study investigates the details of its mechanistic course based on NMR titration, kinetic measurements competition experiments, and deuterium labeling. It concludes a two-step procedure consisting of syn-aminopalladation with an unligated palladium(II) catalyst state followed by oxidation to palladium(IV) and subsequent C-N bond formation to give the final products as cyclic diamines. Related reactions employing sulfamides give rise to aminoalkoxy-functionalization of alkenes. This process was investigated employing deuterated alkenes and found to follow an identical mechanism where stereochemistry is concerned. It exemplifies the importance of cationic palladium(IV) intermediates prior to the final reductive elimination from palladium and proves that the nucelophile for this step stems from the immediate coordination sphere of the palladium(IV) precursor. These results have important implications for the general development of alkene 1,2-difunctionalization and for the individual processes of aminopalladation and palladium-catalyzed Calkyl-N bond formation.
- Muniz, Kilian,Hoevelmann, Claas H.,Streuff, Jan
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p. 763 - 773
(2008/09/19)
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- Lewis acid catalyzed amino-Claisen rearrangement: A facile one pot synthesis of 2-allylarylamines from N-allylarylamines
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Boron trifluoride-diethyl ether complex efficiently catalyzes a variety of amino-Claisen rearrangements of N-allylarylamines 1a-g to afford 2-allylarylamines 2a-g in moderate to good yields. N-allylarylamines having electron deficient substituents undergo
- Jain, Seema,Pandey, Neelesh,Kishore
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p. 529 - 531
(2008/09/18)
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- Pd(II)-catalyzed enantioselective oxidative tandem cyclization reactions. Synthesis of indolines through C-N and C-C bond formation
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We have developed an efficient Pd(II)-catalyzed enantioselective oxidative tandem cyclization strategy using molecular oxygen as a green oxidant for the double 5-exo-trig cyclizations of N-(2-allylaryl) amides to afford a variety of indolines in good yiel
- Yip, Kai-Tai,Yang, Min,Law, Ka-Lun,Zhu, Nian-Yong,Yang, Dan
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p. 3130 - 3131
(2007/10/03)
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- Proton catalyzed amino-Claisen rearrangement: A practical one step approach to the synthesis of 2-allylarylamines from N-allylarylamines
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Proton catalyzed amino-Claisen rearrangement of N-allylarylamines (1a-h) afforded 2-al1y1arylamines (2a-h) respectively in moderate to good yields.
- Jain, Seema,Pandey, Neelesh,Kishore
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p. 938 - 940
(2007/10/03)
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- Novel strategies for the solid phase synthesis of substituted indolines and indoles
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Using a polymer-bound selenenyl bromide resin, o-allyl and o-prenyl anilines were cycloaded to afford a series of solid-supported indoline and indole scaffolds. These scaffolds were then functionalized and cleaved via four distinct methods, namely traceless reduction, radical cyclization, radical rearrangement, and oxidative elimination, to afford 2-methyl indolines, polycyclic indolines, 2-methyl indoles, and 2-propenyl indolines, respectively. A number of small combinatorial libraries of compounds reminiscent of certain designed ligands of biological interest were constructed demonstrating the potential utility of the developed methodology to chemical biology studies and the drug discovery process.
- Nicolaou,Roecker,Hughes, Robert,Van Summeren, Ruben,Pfefferkorn, Jeffrey A.,Winssinger, Nicolas
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p. 465 - 476
(2007/10/03)
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