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1.
An efficient method for the synthesis of indole derivatives from readily available pyrimidyl‐substituted anilines and diazo compounds via rhodium(III)‐catalyzed C H bond activation has been developed. This cyclization reaction displays excellent functional group compatibility and regioselectivity, which overcomes some drawbacks of the classical indole synthetic methods and provides a facile approach for the construction of multi‐substituted indole derivatives. The redox‐neutral intermolecular annulation procedure comprises tandem C H bond activation, cyclization, and condensation steps, releasing water and nitrogen as by‐products.
2.
Satyasheel Sharma Aejin Kim Eonjeong Park Jihye Park Minyoung Kim Jong Hwan Kwak Sang Hwi Lee Young Hoon Jung In Su Kim 《Advanced Synthesis \u0026amp; Catalysis》2013,355(4):667-672
A palladium‐catalyzed oxidative acylation of O‐phenyl carbamates with α‐oxocarboxylic acids via selective aromatic C H bond activation is described. This protocol represents the first ortho‐acylation of phenol derivatives, and a catalytic amount of triflic acid additive is crucial for this transformation. 相似文献
3.
Irwan Iskandar Roslan Kian‐Hong Ng Gaik‐Khuan Chuah Stephan Jaenicke 《Advanced Synthesis \u0026amp; Catalysis》2016,358(3):364-369
A wide range of imidazo[1,2‐a]pyridines are accessible from cheap and readily available 2‐aminopyridines and 1,3‐dicarbonyl compounds using a unique CBrCl3/2‐aminopyridine system for bromination at the α‐carbon. 2‐Aminopyridine is not only the substrate but also acts as a bromination shuttle, transferring the bromine atom from CBrCl3 to the α‐carbon of the 1,3‐dicarbonyl. The reaction mechanism involves a series of reversible steps, including an addition reaction with cyclic transition state, to form a bromo‐hemiaminal intermediate. Isolated yields of up to 97% were obtained under mild conditions and at short reaction times in this transition metal‐free, one‐pot synthesis.
4.
Shengming Ma Xuefeng Jiang Xin Cheng Hairong Hou 《Advanced Synthesis \u0026amp; Catalysis》2006,348(15):2114-2124
The activation of C Cl bond of (Z)‐α‐chloroalkylidene‐β‐lactones and (E)‐α‐chloroalkylidene‐β‐lactams via the Suzuki cross‐coupling reaction is reported in this paper. Alkyl, heteroaromatic, substituted phenyl‐ and alkenylboronic acids can be coupled with a wide variety of α‐chloroalkylidene‐β‐lactones and β‐lactams in excellent yields within a short period of time. The cross‐coupling reaction of optically active substrates leads to the optically active compounds without racemization of the corresponding chiral center. 相似文献
5.
Lutz Ackermann Rubn Vicente Robert Born 《Advanced Synthesis \u0026amp; Catalysis》2008,350(5):741-748
Generally applicable, palladium‐catalyzed direct arylations of 1,2,3‐triazoles with aryl chlorides were accomplished through conventional heating at reaction temperatures of 105–120 °C. Thereby, intra‐ and intermolecular C H bond functionalizations were achieved with a variety of differently substituted chlorides as electrophiles, bearing numerous valuable functional groups. 相似文献
6.
A novel rhodium(III)‐catalyzed direct functionalization of ortho C H bonds of benzoic acid derivatives and an intramolecular cyclization sequence generates 3‐substituted phthalides in moderate to good yields. This cascade cyclization involves a Grignard‐type arylation of an aldehyde and subsequent intramolecular nucleophilic substitution. No theoretical waste except for water is generated in the reaction. 相似文献
7.
γ‐Fluoro‐α, β‐unsaturated carboxylic esters 7a, 7b and 7d and 4‐fluoro‐4‐phenylbut‐3‐enoic ester ( 8 ) are obtained by two alternative pathways from 2‐fluoro aldehydes 5a—d , either by Horner—Wadsworth—Emmons reaction or by Wittig reaction. The aldehydes 5a—d are prepared by Swern oxidation of the corresponding fluorohydrins 4a—d . These are available from α‐olefins by bromofluorination, bromineby‐acetate replacement and subsequent hydrolysis. 相似文献
8.
Xiaowen Xu Liqin Zhao Yiqun Li Jean‐Franois Soul Henri Doucet 《Advanced Synthesis \u0026amp; Catalysis》2015,357(13):2869-2882
Herein, we report on the sequential palladium‐catalyzed intermolecular followed by intramolecular direct arylations of 1‐(2‐bromobenzyl)imidazoles. We found that, in the presence of 1 mol% palladium acetate and potassium acetate as base, the intermolecular reaction between 1‐(2‐bromobenzyl)imidazole derivatives and electron‐deficient aryl bromides proceeded faster than the intramolecular reaction, allowing us to prepare medium‐size polycyclic imidazoles after a second Pd‐catalyzed intramolecular arylation. These iterative direct arylations allowed the synthesis of fused nitrogen‐containing heterocycles with a 5‐ or 7‐membered‐ring in only two steps. Some reactions have also been performed as a one‐pot procedure using 2 mol% of palladium acetate in the presence of a larger amount of base (3 equiv.).
9.
Yuming Cui Lingzi Fu Jian Cao Yuan Deng Jianxiong Jiang 《Advanced Synthesis \u0026amp; Catalysis》2014,356(6):1217-1222
A palladium‐catalyzed intramolecular direct arylation reaction was developed and two efficient one‐pot sequential direct arylation/Suzuki–Miyaura coupling and intra/intermolecular direct arylation reations were also realized. The method provides a simple and straightforward procedure for the synthesis and further functionalization of dibenzophosphole oxides from easily accessible ortho‐halodiarylphosphine oxides in good to excellent yields.
10.
Nicola Della Ca' Elena Motti Antonio Mega Marta Catellani 《Advanced Synthesis \u0026amp; Catalysis》2010,352(9):1451-1454
A catalytic synthesis of selectively substituted phenanthridines is achieved through a reaction sequence involving palladium/norbornene‐catalyzed unsymmetrical aryl‐aryl and Heck couplings followed by aza‐Michael and retro‐Mannich reactions. In spite of the many steps involved the method is very simple and allows the formation of selectively substituted phenanthridines under mild conditions in a straightforward one‐pot reaction starting from readily available aryl iodides and bromides. 相似文献
11.
Kyoji Tsuchikama Yu‐ki Hashimoto Kohei Endo Takanori Shibata 《Advanced Synthesis \u0026amp; Catalysis》2009,351(17):2850-2854
A directed cyclization‐dehydration cascade of α‐aryloxy ketones and α‐arylamino ketones was efficiently catalyzed by a cationic iridium‐BINAP complex, which afforded various types of 4‐substituted benzofurans and indoles in high yields with complete regioselectivity. The newly developed protocol also enabled the enantioselective preparation of chiral 4‐acetyloxindole using a chiral iridium catalyst. 相似文献
12.
Ming Yu Yongju Xie Jinheng Li Yuhong Zhang 《Advanced Synthesis \u0026amp; Catalysis》2011,353(16):2933-2938
Palladium‐catalyzed direct mono‐ and diarylations involving C(sp3) H cleavage at the γ‐position of acrylamides are described. The monoarylation products can be obtained with ortho‐substituted aryl halides. Single crystal X‐ray diffraction has shown that the double bond has shifted towards the introduced aryl group to afford the γ‐arylated β,γ‐unsaturated amide products. A second arylation occurs when less sterically hindered aryl halides are employed. This chemistry offers a novel disconnection for the synthesis of γ‐arylated compounds. 相似文献
13.
Palladium‐Catalyzed Oxidative Heck‐Type Allylation of β,β‐Disubstituted Enones with Allyl Carbonates
Weiwei Jin Qin Yang Ping Wu Jiping Chen Zhengkun Yu 《Advanced Synthesis \u0026amp; Catalysis》2014,356(9):2097-2102
The palladium‐catalyzed oxidative Heck‐type allylation of β,β‐disubstituted enones, i.e., α‐oxoketene dithioacetals, was efficiently realized with allyl carbonates, providing a concise route to highly functionalized dienes. The present synthetic methodology utilizes the substrate activation strategy to activate the C H bond of β,β‐disubstituted enones by introduction of a 1,2‐dithiolane functionality to make the enone substrate highly polarized and thus increase its reactivity, demonstrating rare examples for transition metal‐catalyzed allylic substitution of ß,ß‐disubstituted enones through a Heck‐type allylation process.
14.
Tao Liu Haijun Yang Yuyang Jiang Hua Fu 《Advanced Synthesis \u0026amp; Catalysis》2013,355(6):1169-1176
A novel, easy and useful copper‐catalyzed selective acylation of secondary anilines with ethyl glyoxalate has been developed, and the corresponding indoline‐2,3‐dione derivatives were prepared. The procedure comprises the sequential intermolecular copper‐catalyzed selective oxidative ortho‐site aromatic acylation of the NH group in secondary anilines and intramolecular nucleophilic attack of the NH group to the ester. The inexpensive, easy and efficient method should provide a new strategy for synthesis of dicarbonyl compounds. 相似文献
15.
Venkatachalam Rajeshkumar Fu‐Wei Chan Shih‐Ching Chuang 《Advanced Synthesis \u0026amp; Catalysis》2012,354(13):2473-2483
An extraordinarily efficient hybrid acids‐assisted, palladium‐catalyzed and chelating‐group‐assisted C H bond activation of N‐sulfonyl‐2‐aminobiaryls and their annulations with [60]fullerene via sequential C C and C N bond formation at room temperature to afford [60]fulleroazepines is demonstrated. The formation of [60]fulleroazepines is highly regioselective and tolerant to both electron‐withdrawing and electron‐donating groups on the aryl moiety and the reaction gives monofunctionalized fullerenes in good yields (up to 54% isolated yield and 92% based on converted C60). 相似文献
16.
Nicola Della Ca' Elena Motti Marta Catellani 《Advanced Synthesis \u0026amp; Catalysis》2008,350(16):2513-2516
Selectively substituted phenanthridine derivatives are obtained by a facile reaction of o‐alkylated aryl iodides, o‐bromoarenesulfonylanilines and activated olefins in the presence of palladium and norbornene as catalysts. The reaction takes place under mild conditions to give the products in satisfactory yields using readily available starting materials. 相似文献
17.
Likun Jin Jie Feng Guoping Lu Chun Cai 《Advanced Synthesis \u0026amp; Catalysis》2015,357(9):2105-2110
A metal‐free C C bond formation method via the oxidative cross‐coupling reaction of isochroman and indole derivatives was established. Various α‐fuctionalized cyclic ethers were achieved in satisfactory yields using di‐tert‐butyl peroxide (DTBP) as the oxidant. This method is also a potentially efficient strategy for the construction of cyclic ether‐containing targets.
18.
Xiaolan Chen Xu Li Zhibo Qu Diandian Ke Lingbo Qu Likun Duan Wenpeng Mai Jinwei Yuan Jianyu Chen Yufen Zhao 《Advanced Synthesis \u0026amp; Catalysis》2014,356(9):1979-1985
A synthetic strategy has been developed for the synthesis of 2‐dialkylaminoquinolines from easily available quinoline N‐oxides, tertiary amines, diisopropyl H‐phosphonate and carbon tetrachloride (CCl4) in one pot under metal‐free conditions at room temperature.
19.
A new approach for the synthesis of novel annulated‐pyrazoles is presented. This protocol includes an intermolecular condensation followed by a copper‐mediated intramolecular C N or C O coupling reaction. The method is applied to a range of substituted 4‐iodopyrazolecarbaldehydes which react with 1,2‐phenylenediamines or 2‐aminophenols to yield substituted 2,4‐ or 1,4‐dihydrobenzo[b]pyrazolo[4,3‐e][1,4]diazepines or substituted‐2H‐ or 1H‐benzo[b]pyrazolo[3,4‐f][1,4]oxazepines, respectively. 相似文献
20.
Yi‐Yun Yu Adwait R. Ranade Gunda I. Georg 《Advanced Synthesis \u0026amp; Catalysis》2014,356(17):3510-3518
A transition metal‐free, regioselective C‐5 trifluoromethylation of 2,3‐dihydropyridin‐4(1H)‐ones (cyclic enaminones) with trimethyl(trifluoromethyl)silane (TMSCF3) was developed that proceeds under mild conditions at room temperature. This direct transformation was successful with both electron‐rich and electron‐deficient cyclic enaminones. This method bypasses substrate prefunctionalization and transition metal catalysis, and allows the convenient and direct access to a variety of medicinally important 3‐trifluoromethylpiperidine derivatives. This chemistry also represents a rare example of a direct trifluoromethylation of an internal olefinic C H bond. A radical mechanism is proposed for this reaction.