- Cyclobutane-cleavage of anti-head-to-head coumarin and quinolinone homo- and cross-dimers via single- and two-photon-absorption photochemistry
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The light-driven cleavage of cyclobutane containing systems via [2 + 2] cycloreversion, such as di-coumarin, is an important yet poorly investigated photochemical reaction. Its applications can be found in smart crosslinking polymers or light-activated drug release. We report the increased cleavage efficiencies of the coumarins lactam analog quinolinone for single-photon as well as two-photon-absorption experiments. To investigate the structure-function relationship of the molecular substitution pattern and its influence on the photoactivity, a coumarin-quinolinone cross-dimer was synthesized and investigated towards its cleavage efficiencies in single-photon as well as two-photon photocleavage. The cross-dimer shows a lower cleavage efficiency than both homo-dimers. The presented results are of interest, e.g., for applications utilizing highly efficient cleavage reactions in symmetric or asymmetric molecular frameworks.
- Bieniek, Nikolai,Inacker, Sebastian,Kim, Hee-Cheol,Hampp, Norbert
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Read Online
- Photoredox Cyclization of N-Arylacrylamides for Synthesis of Dihydroquinolinones
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Metal- and additive-free photoredox cyclization of N-arylacrylamides is herein reported that provides a concise access to the formation of dihydroquinolinones. In this protocol, sustainable visible light was used as the energy source, and the organic light-emitting molecule 4CzIPN served as the efficient photocatalyst. This reaction system features exclusive 6-endo-trig cyclization selectivity with a generally good yield of a range of functionalized dihydroquinolinones and dihydrobenzoquinolinones. Mechanistical studies reveal the feasibility of both 1,3-H shift and intersystem crossing of the diradical intermediate.
- Liu, Zhaosheng,Zhong, Shuai,Ji, Xiaochen,Deng, Guo-Jun,Huang, Huawen
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supporting information
p. 349 - 353
(2021/12/27)
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- Chlorination Reaction of Aromatic Compounds and Unsaturated Carbon-Carbon Bonds with Chlorine on Demand
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Chlorination with chlorine is straightforward, highly reactive, and versatile, but it has significant limitations. In this Letter, we introduce a protocol that could combine the efficiency of electrochemical transformation and the high reactivity of chlorine. By utilizing Cl3CCN as the chloride source, donating up to all three chloride atom, the reaction could generate and consume the chlorine in situ on demand to achieve the chlorination of aromatic compounds and electrodeficient alkenes.
- Liu, Feng,Wu, Na,Cheng, Xu
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p. 3015 - 3020
(2021/05/05)
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- Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant
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An unprecedented N-demethylation of N-methyl amides has been developed by use of N-fluorobenzenesulfonimide as an oxidant with the aid of a copper catalyst. The conversion of amides to carbinolamines involves successive single-electron transfer, hydrogen-atom transfer, and hydrolysis, and is accompanied by formation of N-(phenylsulfonyl)benzenesulfonamide. Carbinolamines spontaneously decompose to N-demethylated amides and formaldehyde, because of their inherent instability.
- Yi, Xuewen,Yi, Xuewen,Lei, Siyu,Liu, Wangsheng,Che, Fengrui,Yu, Chunzheng,Liu, Xuesong,Wang, Zonghua,Zhou, Xin,Zhang, Yuexia
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supporting information
p. 4583 - 4587
(2020/05/05)
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- Synthesis of hydroxyl-containing oxindoles and 3,4-dihydroquinolin-2-ones through oxone-mediated cascade arylhydroxylation of activated alkenes
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Hydroxyl-containing compounds are highly value-Added organic molecules, and the establishment of novel methodologies for their elaboration is a long-standing challenge in organic synthesis. Here the first oxone-mediated direct arylhydroxylation of activat
- Zhang, Ming-Zhong,Liu, Long,Gou, Quan,Wang, Qi,Li, Yi,Li, Wan-Ting,Luo, Fei,Yuan, Min,Chen, Tieqiao,He, Wei-Min
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supporting information
p. 8369 - 8374
(2020/12/28)
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- Rh(i)-Catalyzed regioselective arylcarboxylation of acrylamides with arylboronic acids and CO2
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The first Rh(i)-catalyzed regioselective arylcarboxylation of electron-deficient acrylamides with arylboronic acids under atmospheric pressure of CO2 has been developed. A range of acrylamides and arylboronic acids were compatible with this reaction under redox-neutral conditions, leading to a series of malonate derivatives that are versatile building blocks in organic syntheses.
- Cai, Lei,Fu, Lei,Gao, Yuzhen,Li, Gang,Li, Shangda,Zhou, Chunlin
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supporting information
p. 7328 - 7332
(2020/11/19)
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- Copper(I)-Catalyzed Asymmetric 1,4-Conjugate Hydrophosphination of α,β-Unsaturated Amides
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A catalytic asymmetric conjugate hydrophosphination of α,β-unsaturated amides is accomplished by virtue of the strong nucleophilicity of copper(I)-PPh2 species, which provides an array of chiral phosphines bearing an amide moiety in high to excellent yields with excellent enantioselectivity. Furthermore, the dynamic kinetic resolution of unsymmetrical diarylphosphines (HPAr1Ar2) is successfully carried out through the copper(I)-catalyzed conjugate addition to α,β-unsaturated amides, which affords P-chiral phosphines with good-to-high diastereoselectivity and high enantioselectivity. 1H NMR studies show that the precoordination of HPPh2 to copper(I)-bisphosphine complex is critical for the efficient deprotonation by Barton's Base. Moreover, the relative stability of the copper(I)-(R,RP)-TANIAPHOS complex in the presence of excessive HPPh2, confirmed by 31P NMR studies, is pivotal for the high asymmetric induction, as the ligand exchange between bisphosphine and HPPh2 would significantly reduce the enantioselectivity. At last, a double catalytic asymmetric conjugate hydrophosphination furnishes the corresponding product in high yield with high diastereoselectivity and excellent enantioselectivity, which is transformed to a chiral pincer palladium complex in moderate yield. This chiral palladium complex is demonstrated as an excellent catalyst in the asymmetric conjugate hydrophosphination of chalcone.
- Li, Yan-Bo,Tian, Hu,Yin, Liang
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supporting information
p. 20098 - 20106
(2021/01/01)
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- Catalyst-Free, Direct Electrochemical Tri- and Difluoroalkylation/Cyclization: Access to Functionalized Oxindoles and Quinolinones
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The catalyst-free electrochemical di- and trifluoromethylation/cyclization of N-substituted acrylamides was realized under external oxidant-free conditions. The strategy provides expedient access to fluoroalkylated oxindoles and 3,4-dihydroquinolin-2(1H)-ones with ample scope and broad functional group tolerance by mild, direct electrolysis of sodium sulfinates in an undivided cell. Detailed mechanistic studies provided strong support for a SET-based reaction manifold.
- Ruan, Zhixiong,Huang, Zhixing,Xu, Zhongnan,Mo, Guangquan,Tian, Xu,Yu, Xi-Yong,Ackermann, Lutz
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supporting information
p. 1237 - 1240
(2019/02/19)
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- Photocatalytic C-C Bond Activation of Oxime Ester for Acyl Radical Generation and Application
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A unified strategy to generate acyl radical from oxime ester via selective C-C bond activation is reported. Under visible-light irradiation, single-electron transfer from fac-Ir(ppy)3 to related oxime takes place followed by a fast β-fragment of C-C bond to yield aryl and aliphatic acyl radicals, subsequently captured by diverse Michael acceptors. More interestingly, the single-electron transfer enables coupling with energy transfer of the excited fac-Ir(ppy)3 via enone intermediate formed in situ for cyclobutane formation.
- Fan, Xiuwei,Lei, Tao,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 4153 - 4158
(2019/06/08)
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- Heterocoumarins Are Selective Carbonic Anhydrase IX and XII Inhibitors with Cytotoxic Effects against Cancer Cells Lines
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We have synthesized a new series of coumarin-based compounds demonstrating high selectivity and potent effects with low nanomolar affinity against the tumor associated carbonic anhydrase (CA, EC 4.2.1.1) isoforms hCA IX and XII. A number of these compounds were evaluated ex vivo against human prostate (PC3) and breast (MDA-MB-231) cancer cell lines. Compounds 4b and 15 revealed effective cytotoxic effects after 48 h of incubation in both normoxic and hypoxic conditions with PC3 cancer cell line. However, compound 3 showed selective cytotoxic effects against MDA-MB-231 in hypoxic condition. These results may be of particular importance for the choice of future drug candidates targeting hypoxic tumors and metastases, considering the fact that a selective carbonic anhydrase CA IX inhibitor (SLC-0111) is presently in phase II clinical trials.
- Angeli, Andrea,Trallori, Elena,Carta, Fabrizio,Di Cesare Mannelli, Lorenzo,Ghelardini, Carla,Supuran, Claudiu T.
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supporting information
p. 947 - 951
(2018/09/12)
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- Ligand- and Additive-Controlled Pd-Catalyzed Aminocarbonylation of Alkynes with Aminophenols: Highly Chemo- and Regioselective Synthesis of α,β-Unsaturated Amides
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This work describes the chemo- and regioselective direct aminocarbonylation of alkynes and aminophenols to form hydroxy-substituted α,β-unsaturated amides in good to excellent yields. The latter are valuable compounds in pharmaceuticals and natural products. By a simple choice of different ligands and additives, branched or linear isomers could be selectively formed in excellent regioselectivity. Using a combination of boronic acid and 5-chlorosalicylic acid ( BCSA ) as the additives, linear amides were obtained in high yields and selectivities using 1,2-bis(di-tert-butylphosphinomethyl)benzene (DTBPMB) as the ligand. On the other hand, branched amides could be approached by introducing 1,3-bis(diphenylphosphino)propane as the ligand and p-TsOH·H2O as the additive. In addition to the hydroxyl group, other functional substituents, such as carboxyl and vinyl groups, could also be tolerated using this method. As an application of this strategy, the natural product avenanthramide A could be synthesized directly in 84% yield and in 99% regioselectivity via the carbonylation of 2-amino-5-hydroxybenzoic acid and 4-ethynylphenol. Further studies show that the ligands and the additives are keys to good yields and selectivities.
- Sha, Feng,Alper, Howard
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p. 2220 - 2229
(2017/08/09)
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- Iron-Catalyzed Synthesis of Oxindoles: Application to the Preparation of Pyrroloindolines
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A novel and highly efficient synthetic approach to pyrroloindolines has been developed. The process is based on tandem radical addition/cyclization with inexpensive iron catalyst. This method tolerates a wide range of N-methyl-N-arylacrylamides as well carbamoyl radicals, providing access to a variety of functionalized 3,3-disubstituted oxindoles, key intermediates for many bioactive pyrroloindolines such as (±)-esermethole, (±)-deoxyeseroline, and (±)-physovenol methyl ether.
- Correia, Valquírio G.,Abreu, Juliana C.,Barata, Caio A. E.,Andrade, Leandro H.
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supporting information
p. 1060 - 1063
(2017/03/15)
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- Metal-Free Synthesis of 3-Arylquinolin-2-ones from Acrylic Amides via a Highly Regioselective 1,2-Aryl Migration: An Experimental and Computational Study
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Combined experimental and theoretical investigations into the phenyliodine bis(trifluoroacetate) (PIFA)-mediated reaction of N-arylcinnamamide to produce 3-arylquinolin-2-one derivatives have been conducted. High regioselectivity during the aryl migration process was observed in 3,3-disubstituted acrylamides. Density functional theory calculation was conducted in an attempt to understand the mechanism and the origin of the regioselectivity. On the basis of both the experimental and the theoretical results, a mechanism involving an oxidative annulation, followed by an aryl migration, has been proposed. The annulation is the regioselectivity determining step.
- Liu, Le,Zhang, Tonghuan,Yang, Yun-Fang,Zhang-Negrerie, Daisy,Zhang, Xinhao,Du, Yunfei,Wu, Yun-Dong,Zhao, Kang
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p. 4058 - 4065
(2016/06/08)
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- A novel and facile synthesis of 4-arylquinolin-2(1H)-ones under metal-free conditions
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Abstract A novel and facile synthesis of 4-arylquinolin-2(1H)-ones without metal catalysis has been developed. This reaction involved cyclization/elimination steps and was performed under metal-free conditions using inexpensive reagents such as NaI, selec
- Sun, Bin,Mai, Wen-Peng,Yang, Liang-Ru,Mao, Pu,Yuan, Jin-Wei,Xiao, Yong-Mei
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p. 977 - 979
(2015/08/19)
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- Rh-Catalyzed Domino Addition-Enolate Arylation: Generation of 3-Substituted Oxindoles via a Rh(lll) Intermediate
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A Rh-catalyzed domino conjugate addition-arylation sequence via a Rh(III) intermediate is reported. This process involving a proposed intramolecular oxidative addition of a rhodium enolate was utilized to achieve the synthesis of 3-substituted oxindole derivatives in moderate to excellent yields.
- Jang, Young Jin,Yoon, Hyung,Lautens, Mark
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supporting information
p. 3895 - 3897
(2015/08/18)
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- Two consecutive palladium(II)-promoted C-H alkenylation reactions for the synthesis of 3-alkenylquinolones
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Highly substituted quinolones are obtained through an efficient and atom economical procedure that involves two consecutive palladium(II)-catalyzed C-H alkenylation reactions. A selective 6-endo intramolecular C-H alkenylation leads to 4-substituted quinolones that have been further functionalized at C-3 through a second intermolecular C-H alkenylation reaction.
- Ortiz-de-Elguea, Vernica,Sotomayor, Nuria,Lete, Esther
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p. 463 - 473
(2015/03/05)
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- SYNTHESIS OF FUNCTIONALIZED AND UNFUNCTIONALIZED OLEFINS VIA CROSS AND RING-CLOSING METATHESIS
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The invention is directed to the cross-metathesis and ring-closing metathesis reactions between geminal disubstituted olefins and terminal olefins, wherein the reaction employs a Ruthenium or Osmium metal carbene complex. Specifically, the invention relates to the synthesis of alpha-functionalized or unfunctionalized olefins via intermolecular cross-metathesis and intramolecular ring-closing metathesis using a ruthenium alkylidene complex. The catalysts preferably used in the invention are of the general formulawherein:M is ruthenium or osmium;X and Xare each independently an anionic ligand;L is a neutral electron donor ligand; and,R, RR, R, R, and Rare each independently hydrogen or a substituent selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, aryl, C1-C20 carboxylate, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylthio, C1-C20 alkylsulfonyl and C1-C20 alkylsulfinyl.
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Paragraph 0018; 0024
(2015/11/09)
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- The synthesis of 3,4-disubstituted dihydroquinolin-2(1H)-one under metal-free conditions in aqueous solution
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A novel route toward 3,4-disubstituted dihydroquinolin-2(1H )-ones via radical process has been developed in aqueous solution without metals. This method offers a new and simple route for the synthesis of skeleton of dihydroquinolin-2(1H )-one in one step
- Wang, Hongyan,Sun, Bin,Yang, Jun,Wang, Jitao,Mao, Pu,Yang, Liangru,Mai, Wenpeng
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p. 542 - 545
(2014/12/10)
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- Silver-catalyzed radical tandem cyclization for the synthesis of 3,4-disubstituted dihydroquinolin-2(1 H)-ones
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A silver-catalyzed tandem decarboxylative radical addition/cyclization of N-arylcinnamamides with aliphatic carboxylic acids is reported. This method affords a novel and straightforward route to various 3,4-disubstituted dihydroquinolin-2(1H)-ones in aque
- Mai, Wen-Peng,Wang, Ji-Tao,Yang, Liang-Ru,Yuan, Jin-Wei,Xiao, Yong-Mei,Mao, Pu,Qu, Ling-Bo
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supporting information
p. 204 - 207
(2014/01/23)
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- Silver-catalyzed radical tandem cyclization: An approach to direct synthesis of 3-acyl-4-arylquinolin-2(1 H)-ones
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A silver-catalyzed efficient and practical synthesis of 3-acyl-4-arylquinolin-2(1H)-ones or 3-acyl-4-aryldihydroquinolin-2(1H)-ones through intermolecular radical addition/cyclization in aqueous solution is reported. This method provides a novel, highly e
- Mai, Wen-Peng,Sun, Gang-Chun,Wang, Ji-Tao,Song, Ge,Mao, Pu,Yang, Liang-Ru,Yuan, Jin-Wei,Xiao, Yong-Mei,Qu, Ling-Bo
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p. 8094 - 8102
(2015/03/18)
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- PhI(OCOCF3)2-mediated C-C bond formation concomitant with a 1,2-Aryl shift in a metal-free synthesis of 3-arylquinolin-2-ones
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The reaction of the readily available N-methyl-N-phenylcinnamamides with phenyliodine bis(trifluoroacetate) (PIFA) in the presence of Lewis acids provides a general and efficient assembly of a variety of 3-arylquinolin-2-one compounds. This novel approach features not only metal-free oxidative C(sp 2)-C(sp2) bond formation but also an exclusive 1,2-aryl migration.
- Liu, Le,Lu, Hang,Wang, Hong,Yang, Chao,Zhang, Xiang,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
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supporting information
p. 2906 - 2909
(2013/07/26)
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- NBu4NI-catalyzed unexpected amide bond formation between aldehydes and aromatic tertiary amines
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A novel and practical amide bond formation method has been developed without the need for any metals. This method provides a novel route for amide bond formation, in the presence of an nBu4NI/TBHP catalyst system, from readily available aldehydes and aromatic tertiary amines.
- Mai, Wen-Peng,Song, Ge,Yuan, Jin-Wei,Yang, Liang-Ru,Sun, Gang-Chun,Xiao, Yong-Mei,Mao, Pu,Qu, Ling-Bo
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p. 3869 - 3872
(2013/04/24)
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- NBu4NI-catalyzed oxidative amidation of aldehydes with tertiary amines
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An efficient oxidative coupling protocol for amide formation has been developed. Various tertiary amines and aromatic aldehydes were oxidized to their corresponding tertiary amides in moderate to good yields in the presence of a simple nBu4NI-catalyst.
- Wang, Shan,Wang, Jian,Guo, Rui,Wang, Gao,Chen, Shan-Yong,Yu, Xiao-Qi
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supporting information
p. 6233 - 6236
(2013/10/22)
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- A novel one-step synthesis of benzo[b]furo[3,2-b]pyridines having an amino group at the 4-position from benzo[b]furo[3,2-d][1,3]oxazine
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A novel one-step synthesis of benzo[b]furo[3,2-b]pyridines having an amino group at the 4-position from benzo[b]furo[3,2-d][1,3]oxazine by treatment of various amines is described.
- Tabuchi, Yukako,Kakumoto, Yusa,Uchimoto, Hitomi,Kawasaki, Ikuo,Ohishi, Yoshitaka,Nishide, Kiyoharu
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p. 177 - 191
(2013/03/13)
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- Amide bond formation through iron-catalyzed oxidative amidation of tertiary amines with anhydrides
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A general and efficient method for amide bond synthesis has been developed. The method allows for synthesis of tertiary amides from readily available tertiary amines and anhydrides in the presence of FeCl2 as catalyst and tert-butyl hydroperoxide in water (T-Hydro) as oxidant. Mechanistic studies indicated that the in situ-generated α-amino peroxide of tertiary amine and iminium ion act as key intermediates in this oxidative transformation.
- Li, Yuanming,Ma, Lina,Jia, Fan,Li, Zhiping
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p. 5638 - 5646
(2013/07/26)
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- Oxindole synthesis by palladium-catalysed aromatic C-H alkenylation
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A strategy involving palladium-catalysed aromatic C-H functionalisation/ intramolecular alkenylation provides a convenient and direct synthesis of 3-alkylideneoxindoles. In the presence of 5 mol% of PdCl2MeCN 2 and AgOCOCF3, a wide variety of N-cinnamoylanilines gave 3-alkylideneoxindoles in moderate to good yield. The Royal Society of Chemistry.
- Ueda, Satoshi,Okada, Takahiro,Nagasawa, Hideko
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supporting information; experimental part
p. 2462 - 2464
(2010/08/13)
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- Palladium(II)-catalyzed regioselective carbonylative coupling of aniline derivatives with terminal aryl acetylenes to give acrylamides under syngas conditions
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The carbonylative coupling of aniline derivatives (1a-h) with terminal aryl acetylenes (2a, b) catalyzed by Pd(OAc)2 and 1,4- bis(diphenylphosphino)butane (dppb) under syngas conditions affords acrylamide derivatives 3 or 3' in excellent yields
- El Ali,El-Ghanam,Fettouhi,Tijani
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p. 5761 - 5764
(2007/10/03)
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