- Easy Access to Crystalline Indolines via Hydrogen Bond Transfer
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Several indoline derivatives with specific geometries are biologically active and have inhibitor properties. Many indolines are a key part of natural products. Much attention has been focused on the development of synthetic routes for their easy access. C
- Khatoon, Saira,Vgenopoulou, Aggeliki,Naseer, Muhammad Moazzam,Shirinfar, Bahareh,Kariuki, Benson M.,Dege, Necmi,Ahmed, Nisar
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- A general, regioselective approach to the synthesis of ortho allylanilines
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Readily available 2,1-benzothiazines can be alkylated via deprotonation with butyllithium followed by treatment with iodomethyltrimethylsilane. Subsequent treatment with fluoride and hydrolysis leads to ortho allyl anilines in high yield. The reaction is general and regioselective by virtue of these characteristics being present in the Lewis acid mediated reaction of alkenes and sulfonimidoyl chlorides, the reaction which leads to the 2,1-benzothiazines used as starting materials.
- Harmata, Michael
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- Regioselective Radical Arene Amination for the Concise Synthesis ofortho-Phenylenediamines
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The formation of arene C-N bonds directly from C-H bonds is of great importance and there has been rapid recent development of methods for achieving this through radical mechanisms, often involving reactiveN-centered radicals. A major challenge associated with these advances is that of regiocontrol, with mixtures of regioisomeric products obtained in most protocols, limiting broader utility. We have designed a system that utilizes attractive noncovalent interactions between an anionic substrate and an incoming radical cation in order to guide the latter to the areneorthoposition. The anionic substrate takes the form of a sulfamate-protected aniline and telescoped cleavage of the sulfamate group after amination leads directly toortho-phenylenediamines, key building blocks for a range of medicinally relevant diazoles. Our method can deliver both free amines and monoalkyl amines allowing access to unsymmetrical, selectively monoalkylated benzimidazoles and benzotriazoles. As well as providing concise access to valuableortho-phenylenediamines, this work demonstrates the potential for utilizing noncovalent interactions to control positional selectivity in radical reactions.
- Gillespie, James E.,Morrill, Charlotte,Phipps, Robert J.
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supporting information
p. 9355 - 9360
(2021/07/19)
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- Catalytic C(sp2)?H amination reactions using dinickel imides
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C?H amination reactions are valuable transformations for the construction of C?N bonds. Due to their relatively high bond dissociation energies, C(sp2)?H bonds are generally not susceptible toward direct nitrene insertion, necessitating alternative mechanisms for C?H activation. Here, we report that cationic dinuclear (NDI)Ni2 (NDI = naphthyridine?diimine) complexes catalyze intramolecular nitrene insertions into aryl and vinyl C(sp2)? H bonds. Mechanistic studies suggest that a bridging imido ligand supported at a Ni2 site induces C?H activation by a 1,2-addition pathway to generate an azametallacyclic intermediate. This organometallic mechanism contrasts with the electrocyclization/1,2-shift mechanism proposed for analogous transformations using Rh2 catalysts. The implications of these mechanistic differences for the stereoselectivity and chemoselectivity of C?H amination are described.
- Andjaba, John M.,Powers, Ian G.,Uyeda, Christopher,Zeller, Matthias
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supporting information
p. 3794 - 3801
(2020/11/23)
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- 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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supporting information
(2020/03/19)
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- Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
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The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
- Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
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supporting information
(2020/05/18)
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- Intramolecular Aminoazidation of Unactivated Terminal Alkenes by Palladium-Catalyzed Reactions with Hydrogen Peroxide as the Oxidant
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The palladium-catalyzed aminoazidation of aminoalkenes yielding azidomethyl-substituted nitrogen-containing heterocycles was developed. The procedure requires oxidative conditions and occurs at room temperature in the presence of hydrogen peroxide and NaN3 as the azide source. These conditions provide selective exo-cyclization/azidation of the carbon-carbon double bond, furnishing a versatile approach toward five-, six-, and seven-membered heterocyclic rings.
- Beccalli, Egle M.,Broggini, Gianluigi,Foschi, Francesca,Lo Presti, Leonardo,Loro, Camilla,Oble, Julie,Poli, Giovanni,Sala, Roberto
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supporting information
(2020/02/28)
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- Heterogeneous photocatalysis of azides: Extending nitrene photochemistry to longer wavelengths
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The photodecomposition of azides to generate nitrenes usually requires wavelengths in the 300 nm region. In this study, we show that this reaction can be readily performed in the UVA region (368 nm) when catalyzed by Pd-decorated TiO2. In aqueous medium the reaction leads to amines, with water acting as the H source; however, in non-protic and non-nucleophilic media, such as acetonitrile, nitrenes recombine to yield azo compounds, while azirine-mediated trapping occurs in the presence of nucleophiles. The heterogeneous process facilitates catalyst separation while showing great chemoselectivity and high yields.
- Argüello, Juan E.,Lanterna, Anabel E.,Lemir, Ignacio D.,Scaiano, Juan C.
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supporting information
p. 10239 - 10242
(2020/10/02)
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- Indole compound and synthesizing and application methods thereof
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The invention relates to an indole compound and synthesizing and application methods thereof. The indole compound is prepared by selecting specific substituent groups. Experiments find that the indolecompound can achieve good inhibiting effects on prostatic cancer, good in drug-resistance-proofness and low in side effects when applied as an anti-cancer drug; besides, the synthesizing method of the indole compound comprises subjecting a compound with the structure shown as the formula (II), palladium acetate, benzoquinones and organic acids to reaction in solvent to obtain the indole compoundwith the structure shown as the formula (I). Experiment results show that the synthesizing method of the indole compound is low in requirements on substrate and high in product yield.
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Paragraph 0080-0083
(2019/10/22)
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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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supporting information
p. 3890 - 3897
(2019/06/27)
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- Aerobic intramolecular aminothiocyanation of unactivated alkenes promoted by in situ generated iodine thiocyanate
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Aerobic intramolecular aminothiocyanation of unactivated alkenes has been developed by in situ generated iodine thiocyanate under open-flask conditions. This protocol provides a concise and efficient method for synthesizing SCN-containing pyrrolidine, piperidine and indoline derivatives with isolated yields of up to 87%. Furthermore, mixing iodine and sodium thiocyanate with oxygen afforded iodine thiocyanate (ISCN) and dithiocyanatoiodate [I(SCN)2]- which were testified by liquid chromatography mass spectrometry. A mechanistic investigation indicates that iodonium ion and sulfonium ion intermediates might be involved in this transformation.
- Feng, Yangyang,Hussain, Muhammad Ijaz,Zhang, Xiaohui,Shi, Jian,Hu, Wen,Xiong, Yan
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supporting information
p. 2669 - 2676
(2018/05/04)
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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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supporting information
p. 2151 - 2156
(2018/04/26)
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- Exploring the Ring-Closing Metathesis for the Construction of the Solomonamide Macrocyclic Core: Identification of Bioactive Precursors
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New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversity-oriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.
- Cheng-Sánchez, Iván,Carrillo, Paloma,Sánchez-Ruiz, Antonio,Martínez-Poveda, Beatriz,Quesada, Ana R.,Medina, Miguel A.,López-Romero, Juan M.,Sarabia, Francisco
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p. 5365 - 5383
(2018/05/05)
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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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supporting information
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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supporting information
p. 1577 - 1581
(2017/05/05)
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- Copper-Promoted Intramolecular Aminotrifluoromethylation of Alkenes with Langlois Reagent as the Trifluoromethyl Source
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A novel approach for copper-promoted intramolecular aminotrifluoromethylation of alkenes using inexpensive CF3SO2Na as the trifluoromethyl source is described. The feature of this method is the concurrent construction of a five-membered ring and a C-CF3 bond in the simple copper salt/TBHP system. A gram-scale reaction was tested with a slight decrease in the yield. This protocol provides an operationally simple, step-economical and synthetically useful access to a variety of trifluoromethyl indolines, pyrrolidines and lactams.
- Zhang, Hong-Yu,Huo, Wenge,Ge, Chao,Zhao, Jiquan,Zhang, Yuecheng
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supporting information
p. 962 - 965
(2017/05/05)
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- Access to Chiral Hydropyrimidines through Palladium-Catalyzed Asymmetric Allylic C?H Amination
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A palladium-catalyzed asymmetric intramolecular allylic C?H amination controlled by a chiral phosphoramidite ligand was established for the preparation of various substituted chiral hydropyrimidinones, the precursors of hydropyrimidines, in high yields with high enantioselectivities. In particular, dienyl sodium N-sulfonyl amides bearing an arylethene-1-sulfonyl group underwent a sequential allylic C?H amination and intramolecular Diels–Alder (IMDA) reaction to produce chiral fused tricyclic tetrahydropyrimidinone frameworks in high yields and with high levels of stereoselectivity. Significantly, this method was used as the key step in an asymmetric synthesis of letermovir.
- Wang, Pu-Sheng,Shen, Meng-Lan,Wang, Tian-Ci,Lin, Hua-Chen,Gong, Liu-Zhu
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supporting information
p. 16032 - 16036
(2017/11/23)
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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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supporting information
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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supporting information
p. 5449 - 5451
(2016/11/17)
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- 2-(Phenylseleno)ethanesulfon-amide as a novel protecting group for aniline that can be deprotected by a radical reaction
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Anilines were protected as 2-(phenylseleno)ethanesulfonanilide (SeES anilide) via sulfonylation by 2-chlorosulfonyl chloride followed by the conjugate addition of benzeneselenol. The SeES anilide was deprotected by radical reduction using tributyltin hydride in the presence of AIBN. The corresponding anilines were obtained in high yields when the hydride and AIBN were added to the system slowly. Since the radical reaction proceeds under neutral conditions, chemoselective deprotection of the SeES group was accomplished. The SeES anilide was stable under various conditions, including some severe conditions.
- Kihara, Nobuhiro,Mitsuhashi, Yuji,Sato, Makoto,Hirose, Shun-Ichi,Goudo, Erika,Uzawa, Yoshinori,Shirai, Natsumi,Hamamoto, Sari,Iwasaki, Ryo,Fujioka, Akane
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supporting information
p. 2563 - 2566
(2016/06/06)
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- Palladium-catalyzed direct coupling of 2-vinylanilines and isocyanides: An efficient synthesis of 2-aminoquinolines
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Palladium-catalyzed oxidative coupling of 2-vinylanilines and isocyanides constitutes a direct, facile, and efficient approach to 2-aminoquinolines. The procedure, employing palladium acetate and silver carbonate, is attractive in terms of assembly efficiency, functional group tolerance, and operational simplicity. A variety of 2-aminoquinolines were prepared in good to excellent yields.
- Wang, Lijie,Ferguson, Jamie,Zeng, Fanlong
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supporting information
p. 11486 - 11491
(2015/12/04)
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- Copper(II)-catalyzed enantioselective intramolecular cyclization of N-alkenylureas
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The first Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
- Fu, Shaomin,Yang, Honghao,Deng, Yuanfu,Jiang, Huanfeng,Zeng, Wei,Li, Guoqiang
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supporting information
p. 1018 - 1021
(2015/03/30)
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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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supporting information
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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- 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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- Regiodivergent access to five- and six-membered benzo-fused lactams: Ru-catalyzed olefin hydrocarbamoylation
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We report herein a new strategy of the Ru-catalyzed intramolecular olefin hydrocarbamoylation for the regiodivergent synthesis of five- and six-membered benzo-fused lactams starting from N-(2-alkenylphenyl)formamides. Using a combined catalyst of Ru3
- Li, Bin,Park, Yoonsu,Chang, Sukbok
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supporting information
p. 1125 - 1131
(2014/02/14)
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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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supporting information
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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supporting information
p. 13113 - 13116
(2016/02/19)
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- Palladium(0)-catalyzed intramolecular decarboxylative allylation of ortho nitrobenzoic esters
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A Pd/Ag bimetallic system has been developed for the decarboxylative allylation of ortho-nitrobenzoic esters in an intramolecular fashion. In contrast to the typical sp2-sp3 cross-coupling approach which requires air and moisture sensitive preformed organometallic reagents, we provide an alternative route to the synthesis of ortho-allyl nitroarenes from the corresponding ortho-nitrobenzoic acid derivatives. The reaction proceeds through a mechanistically distinct decarboxylative metalation pathway. A cooperative reactivity of palladium and silver is crucial for the reaction outcome.
- Hossian, Asik,Singha, Shantanu,Jana, Ranjan
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supporting information
p. 3934 - 3937
(2014/08/18)
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- Intramolecular aminocyanation of alkenes by N-CN bond cleavage
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A metal-free, Lewis acid promoted intramolecular aminocyanation of alkenes was developed. B(C6F5)3 activates N-sulfonyl cyanamides, thus leading to a formal cleavage of the N-CN bonds in conjunction with vicinal addition o
- Pan, Zhongda,Pound, Sarah M.,Rondla, Naveen R.,Douglas, Christopher J.
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p. 5170 - 5174
(2014/05/20)
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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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- Pd(0)-catalyzed alkene oxy- and aminoalkynylation with aliphatic bromoacetylenes
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Tetrahydrofurans and pyrrolidines are among the most important heterocycles found in bioactive compounds. Cyclization-functionalization domino reactions of alcohols or amines onto olefins constitute one of the most efficient methods to access them. In this context, oxy- and aminoalkynylation are especially important reactions, because of the numerous transformations possible with the triple bond of acetylenes, yet these methods have been limited to the use of silyl protected acetylenes. Herein, we report the first palladium-catalyzed oxy- and aminoalkynylation using aliphatic bromoalkynes, which proceeded with high diastereoselectivity and functional group tolerance. A one-pot hydrogenation of the triple bond gave then access to alkyl-substituted tetrahydrofurans and pyrroldines. Finally, a detailed study of the side products formed during the reaction gave a first insight into the reaction mechanism.
- Nicolai, Stefano,Sedigh-Zadeh, Raha,Waser, Jeroime
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p. 3783 - 3801
(2013/06/26)
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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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supporting information; scheme or table
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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- Synthesis of indolines, indoles, and benzopyrrolizidinones from simple aryl azides
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A simple approach to prepare indolines and benzopyrrolizidinones from ortho-azidoallylbenzenes via a tandem radical addition/cyclization is described. The use of triethylborane to initiate and sustain the process provides the best results. Indolines are easily converted into the corresponding indoles by oxidation with manganese dioxide.
- Brucelle, Fran?ois,Renaud, Philippe
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supporting information; experimental part
p. 3048 - 3051
(2012/08/14)
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- Unexpected conversion of alkyl azides to alkyl iodides and of aryl azides to N-tert-butyl anilines
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In the presence of tert-butyl iodide, alkyl azides are converted into the corresponding iodides at room temperature, whereas, N-t-Bu anilines are obtained from aryl azides under the same experimental conditions. A mechanism is proposed to explain this unusual reactivity.
- Maury, Julien,Feray, Laurence,Bertrand, Michele P.,Kapat, Ajoy,Renaud, Philippe
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p. 9606 - 9611,6
(2020/08/20)
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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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supporting information; scheme or table
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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supporting information; scheme or table
p. 3923 - 3927
(2012/05/20)
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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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- Hg(OTf)2-BINAPHANE-catalyzed enantioselective anilino sulfonamide allyl alcohol cyclization
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Chiral ligands: Hg(OTf)2-catalyzed cyclization of anilino sulfonamide allyl alcohol is described; this reaction gives 2-vinyl indoline derivatives in good yields and excellent enantioselectivity by using a chiral BINAPHANE ligand (see scheme).
- Yamamoto, Hirofumi,Ho, Elisabeth,Namba, Kosuke,Imagawa, Hiroshi,Nishizawa, Mugio
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supporting information; experimental part
p. 11271 - 11274
(2010/11/04)
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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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- Synthesis and structures of fused N-heterocylic carbenes and their rhodium complexes
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New procedures for the synthesis of N-heterocyclic carbenes with multiple fused rings have been developed utilizing a key ring-closing metathesis step. Rhodium complexes were obtained via the pentafluorophenyl carbene adducts. Solid-state structural behav
- Li, Jean,Stewart, Ian C.,Grubbs, Robert H.
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scheme or table
p. 3765 - 3768
(2010/12/20)
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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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- Synthesis of highly substituted dibenzoazocine derivatives by the aza-Claisen rearrangement and intramolecular Heck reaction via 8-exo-trig mode of cyclization
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The synthesis of highly substituted dibenzo-azocine systems is still lacking. An efficient synthetic protocol utilizing the sequential aromatic aza-Claisen rearrangement followed by the implementation of the intramolecular Heck reaction as a key step has been developed for the synthesis of various dibenzo-azocine derivatives of biological relevance.
- Majumdar,Chattopadhyay, Buddhadeb,Samanta, Srikanta
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scheme or table
p. 3178 - 3181
(2009/08/07)
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- Palladium-Catalyzed highly diastereoselective oxidative cascade cyclization reactions
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Isoquinoline and quinoline have been discovered as novel ligands for palladium-catalyzed oxidative cascade cyclization reactions. With our new catalyst systems (Pd(OAc)2/isoquinoline or quinoline), unsaturated anilides cyclize under an oxygen atmosphere (1 atm) to furnish structurally versatile indoline derivatives in good yields. One C-N bond and two C-C bonds are formed in a single step with excellent diastereoselectivities (dr> 24:1).
- Yip, Kai-Tai,Zhu, Nian-Yong,Yang, Dan
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supporting information; scheme or table
p. 1911 - 1914
(2009/09/25)
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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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- Pd-catalyzed arylation/ring-closing metathesis approach to azabicycles
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Palladium-catalyzed arylation followed by Grignard addition to imines and ring-closing metathesis, using Grubbs' catalysts, provides a route to six-, seven-, and eight-membered azabicycles.
- Martínez-Estíbalez, Unai,Sotomayor, Nuria,Lete, Esther
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p. 2919 - 2922
(2008/02/03)
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