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1.
Philip Boehm Sven Roediger Alessandro Bismuto Bill Morandi 《Angewandte Chemie (International ed. in English)》2020,59(41):17887-17896
An efficient palladium‐catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high‐value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl‐containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO. 相似文献
2.
In this study, first direct access to aryl alkyl sulfides employing 2‐phenylpropanal as coupling partner is reported. Diaryl disulfides react with this aldehyde in the presence of morpholine and produce the corresponding sulfide products in high yields. In another part, disulfides are in situ generated in the reaction mixture from aryl halides/CuI/Cyanodithioformate and coupled with 2‐phenylpropanal to access aryl alkyl sulfides. 相似文献
3.
Hong Ji Jianghong Cai Nana Gan Zhaohua Wang Liyang Wu Guorong Li Tao Yi 《Chemistry Central journal》2018,12(1):136
A facile and efficient palladium-catalyzed borylation of aryl (pseudo)halides at room temperature has been developed. Arylboronic esters were expeditiously assembled in good yields and with a broad substrate scope and good functional group compatibility. This approach has been successfully applied to the one-pot two-step borylation/Suzuki–Miyaura cross-coupling reaction, providing a concise access to biaryl compounds from readily available aryl halides. Furthermore, a parallel synthesis of biaryl analogs is accomplished at room temperature using the strategy, which enhances the practical usefulness of this method. 相似文献
4.
Palladium-catalyzed carbonylative cross-coupling reaction of ethynylstibane (PhSbPh(2)) and aryl iodides (Ar-I) is described. The reaction of the stibanes and the halides under 1 atm of carbon monoxide in N,N-dimethylacetamide using a combination of 5 mol% Pd(OAc)(2) and 4 equivalents (20 mol%) of PPh(3) brought about carbonylative cross-coupling reaction to afford arylethynylketones [ArC(O)Ph] in good yields along with a small amount of directly coupled products, aryl acetylens (ArPh). Formation of the side product was completely suppressed by conducting the reaction under high CO pressure (20 atm) conditions. The present method provides a variety of carbonylated products in good yield even with electron-deficient aryl iodides which usually give inferior results due to their tendency to undergo decarbonylation in the cross-coupling reaction of ethynylstibanes and acyl halides. 相似文献
5.
Minghao Zhang Zhiyang Ye Prof. Dr. Wanxiang Zhao 《Angewandte Chemie (International ed. in English)》2023,62(31):e202306248
Enantioselective functionalization of racemic alkyl halides is an efficient strategy to assemble complex chiral molecules, but remains one of the biggest challenges in organic chemistry. The distant and selective activation of unreactive C−H bonds in alkyl halides has received growing interest as it enables rapid generation of molecular complexity from simple building blocks. Here, we reported a cobalt-catalyzed remote borylation of alkyl (pseudo)halides (alkyl−X, X=I, Br, Cl, OTs) with pinacolborane (HBpin) and presented a robust approach for the generation of valuable chiral secondary organoboronates from racemic alkyl halides. This migration borylation reaction is compatible with primary, secondary, and tertiary bromides, offering direct access to a broad range of alkylboronates. The extension of this catalytic system to the borylation of aryl halides was also demonstrated. Preliminary mechanistic studies revealed that this remote borylation involved a radical reaction pathway. 相似文献
6.
Dr. On Ying Yuen Dr. Chau Ming So 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23644-23650
This study describes the first palladium-catalyzed, site-selective α- and γ-arylation of α,β-unsaturated ketones with (hetero)aryl halides. A wide range of hetero(aryl)halides coupled with α,β-unsaturated ketones, and transformation into the arylated products proceeded with excellent to good yields. The site selectivity of the reaction is switchable by simply changing the phosphine ligand to access either α-arylated or γ-arylated products in good to excellent yields by using a low catalyst loading, and the method demonstrates good functional-group compatibility. 相似文献
7.
8.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1522-1527
A simple formylation reaction of aryl halides, aryl triflates, and vinyl bromides under synergistic nickel‐ and organic‐dye‐mediated photoredox catalysis is reported. Distinct from widely used palladium‐catalyzed formylation processes, this reaction proceeds by a two‐step mechanistic sequence involving initial in situ generation of the diethoxymethyl radical from diethoxyacetic acid by a 4CzIPN‐mediated photoredox reaction. The formyl‐radical equivalent then undergoes nickel‐catalyzed substitution reactions with aryl halides and triflates and vinyl bromides to form the corresponding aldehyde products. Significantly, besides aryl bromides, less reactive aryl chlorides and triflates and vinyl halides serve as effective substrates for this process. Since the mild conditions involved in this reaction tolerate a plethora of functional groups, the process can be applied to the efficient preparation of diverse aromatic aldehydes. 相似文献
9.
Single‐Electron‐Transfer‐Induced Coupling of Arylzinc Reagents with Aryl and Alkenyl Halides 下载免费PDF全文
Prof. Eiji Shirakawa Fumiko Tamakuni Eugene Kusano Nanase Uchiyama Wataru Konagaya Ryo Watabe Prof. Tamio Hayashi 《Angewandte Chemie (International ed. in English)》2014,53(2):521-525
Arylzinc reagents, prepared from aryl halides/zinc powder or aryl Grignard reagents/zinc chloride, were found to undergo coupling with aryl and alkenyl halides without the aid of transition‐metal catalysis to give biaryls and styrene derivatives, respectively. In this context, we have already reported the corresponding reaction using aryl Grignard reagents instead of arylzinc reagents. Compared with the Grignard cross‐coupling, the present reaction features high functional‐group tolerance, whereby electrophilic groups such as alkoxycarbonyl and cyano groups are compatible as substituents on both the arylzinc reagents and the aryl halides. Aryl halides receive a single electron and thereby become activated as the corresponding anion radicals, which react with arylzinc reagents, thus leading to the cross‐coupling products. 相似文献
10.
Masami Terasawa Kiyotomi Kaneda Toshinobu Imanaka Shiichiro Teranishi 《Journal of organometallic chemistry》1978,162(3):403-414
A coordinatively unsaturated palladium(0) complex was prepared by the reduction of a polymer-bound palladium(II) chloride complex, which was prepared by the reaction of poly-4-diphenylphosphinomethylstyrene with palladium chloride, with hydrazine in ethanol in the presence of triphenylphosphine. Catalytic activities of the polymerbound palladium(0) complex were examined for three representative types of palladium(0)-induced reactions involving oxidative addition of halides to the metal: (i) vinylic hydrogen substitutions with aryl halides, (ii) acetylenic hydrogen substitutions with aryl halides, (iii) vinylic halogen substitutions with Grignard reagents. Use of the catalyst resulted in formation of corresponding products in good yields. The catalytic activity is comparable to that of analogous homogeneous catalysts, yet is not remarkably lowered on being recycled. 相似文献
11.
双子座季铵盐能够稳定现场产生的纳米钯粒子,该纳米钯粒子能有效地催化一系列芳基硼酸和芳基卤代烃发生Suzuki偶联反应.双子座季铵盐稳定的纳米钯粒子能够在空气中稳定存在,透射电镜(TEM)分析纳米钯粒子呈圆球形,粒径分布在5~25 nm.该方法具有反应条件温和、反应时间短、后处理简单方便等优点. 相似文献
12.
A highly efficient Suzuki cross-coupling reaction between benzylic halides and aryl boronic acids using palladium chloride as catalyst in acetone:water (3:1) as the solvent system has been developed. High yields of products, mild reaction conditions and short reaction times in the absence of ligand are important features of this method. 相似文献
13.
Goossen LJ Rodríguez N Melzer B Linder C Deng G Levy LM 《Journal of the American Chemical Society》2007,129(15):4824-4833
A new strategy for the regiospecific construction of unsymmetrical biaryls is presented, in which easily available salts of carboxylic acids are decarboxylated in situ to give arylmetal species that serve as the nucleophilic component in a catalytic cross-coupling reaction with aryl halides. The catalyst system consists of a copper phenanthroline complex that mediates the extrusion of CO2 from aromatic carboxylates to generate arylcopper species, and a palladium complex that catalyzes the cross-coupling of these intermediates with aryl halides. This bimetallic system allows the direct coupling of various aryl, heteroaryl, or vinyl carboxylic acids with aryl or heteroaryl iodides, bromides, or chlorides at 160 degrees C in the presence of a mild base such as potassium carbonate. The present scope and potential economic impact of the reaction are demonstrated by the synthesis of 42 biaryls, some of which are of substantial industrial relevance. Remaining challenges and future perspectives of the new transformation are discussed. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(49):15899-15903
We describe a nickel‐catalyzed cyanation reaction of aryl (pseudo)halides that employs butyronitrile as a cyanating reagent instead of highly toxic cyanide salts. A dual catalytic cycle merging retro‐hydrocyanation and cross‐coupling enables the conversion of a broad array of aryl chlorides and aryl/vinyl triflates into their corresponding nitriles. This new reaction provides a strategically distinct approach to the safe preparation of aryl cyanides, which are essential compounds in agrochemistry and medicinal chemistry. 相似文献
15.
Nickel‐Catalyzed N‐Arylation of Primary Amides and Lactams with Activated (Hetero)aryl Electrophiles 下载免费PDF全文
Christopher M. Lavoie Preston M. MacQueen Prof. Dr. Mark Stradiotto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18752-18755
The first nickel‐catalyzed N‐arylation of amides with (hetero)aryl (pseudo)halides is reported, enabled by use of the air‐stable pre‐catalyst (PAd‐DalPhos)Ni(o‐tolyl)Cl ( C1 ). A range of structurally diverse primary amides and lactams were cross‐coupled successfully with activated (hetero)aryl chloride, bromide, triflate, tosylate, mesylate, and sulfamate electrophiles. 相似文献
16.
Palladium-catalyzed aminocarbonylations of various (hetero)aryl halides with allylamine using Mo(CO)6 as a solid, in situ CO source, were explored. Microwave-enhanced conditions proved to be highly useful in promoting the conversions in a mere 10-20 min with various (hetero)aryl iodides, bromides and chlorides. The scale-up of a microwave-enhanced aminocarbonylation to 25 mmol scale was performed successfully. 相似文献
17.
Treatment of aryl iodides with indium metal in the presence of lithium chloride leads to the formation of an organoindium reagent capable of participating in cross-coupling reactions under transition-metal catalysis. Combination with aryl halides in the presence of 5 mol % Cl2Pd(dppf) furnishes biaryl compounds in good yields; similarly, reaction with acyl halides or allylic acetates/carbonates in the presence of 5-10 mol % palladium catalyst leads to arylketones and allylic substitution products, respectively, in moderate yields. The reactions are tolerant of the presence of protic solvents, and approximately 85% of the indium metal employed can be recovered by reduction of the residual indium salts with zinc(0). 相似文献
18.
Heck reactions of aryl halides with various olefins and Suzuki reactions of aryl halides with phenylboronic acid catalyzed by palladaphosphacyclobutene have been investigated. The scope of the Heck reaction has been investigated in N,N‐dimethylacetamide at 140 °C using NaOAc as base. Using 0.1% molar ratio of palladaphosphacyclobuyenes, aryl bromides were converted into 1,2‐substitutedethene products in good to high yields through coupling with both vinylarenes and acrylates. Actived aryl chloride reacted with styrene to afford 1,2‐substitutedethene products in moderate yields. The scope of the Suzuki reaction has been conducted in toluene at 110 °C using Cs2CO3 as base. Using 0.1% molar ratio of palladaphosphacyclobutene, aryl bromides reacted with phenylboronic acid to afford diaryl derivatives in excellent yield. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
19.
A palladium catalyst was synthesized using N‐benzyl DABCO chloride and palladium chloride. The structure of this catalyst was characterized and then the catalyst was used in Suzuki cross‐ coupling reaction of different aryl halides with arylboronic acids. All substrates afforded the corresponding products in good to high yields in the presence of low amounts of the catalyst. Under the heating conditions employed, cheaper and more available aryl chlorides gave relatively high yields in the Suzuki reaction. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
Yimin Hu Prof. Dr. Yuan Qu Fenghua Wu Jinghan Gui Yun Wei Qiong Hu Shaowu Wang Prof. Dr. 《化学:亚洲杂志》2010,5(2):309-314
An efficient domino cyclization method for the construction of aza‐podophyllotoxin/aza‐conidendrin derivatives has been established. Reactions of different dienes with aryl halides in the presence of a palladium catalytic system produced different kinds of podophyllotoxin derivatives through a highly regioselective C? H functionalization. Treatment of dienes with aryl halides that have electron‐withdrawing substituents on the phenyl ring created aza‐podophyllotoxin derivatives by means of the functionalization of the C? H bonds ortho to the C? halide bonds of the incoming aryl halides. The reaction of dienes with 1‐iodobenzene or aryl halides that incorporate electron‐donating groups produced aza‐conidendrin derivatives by means of the functionalization of both sp3 C? H and sp2 C? H bonds. The regioselective C? H functionalization for the formation of different pseudo‐podophyllotoxin/‐conidendrin derivatives is proven by analyses of the 1H NMR spectra of the products and selective X‐ray analyses of the structures of the products. Thus, the palladium‐catalyzed domino cyclization of 1,6‐dienes for the preparation of aza‐podophyllotoxin/aza‐conidendrin derivatives can be controlled by selectively controlling the C? H functionalization. 相似文献