共查询到20条相似文献,搜索用时 15 毫秒
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Caitlin M. McMahon Prof. Erik J. Alexanian 《Angewandte Chemie (International ed. in English)》2014,53(23):5974-5977
A palladium‐catalyzed, intermolecular Heck‐type coupling of alkyl iodides and alkenes is described. This process is successful with a variety of primary and secondary unactivated alkyl iodides as reaction partners, including those with hydrogen atoms in the β position. The mild catalytic conditions enable intermolecular C? C bond formations with a diverse set of alkyl iodides and alkenes, including substrates containing base‐ or nucleophile‐sensitive functionality. 相似文献
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Dr. Rylan J. Lundgren Prof. Dr. Mark Stradiotto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):9758-9769
The development of palladium‐catalyzed cross‐coupling reactions has revolutionized the synthesis of organic molecules on both bench‐top and industrial scales. While significant research effort has been directed toward evaluating how modifying various reaction parameters can influence the outcome of a given cross‐coupling reaction, the design and implementation of novel ancillary ligand frameworks has played a particularly important role in advancing the state‐of‐the‐art. This Review seeks to highlight notable examples from the recent chemical literature, in which newly developed ancillary ligands have enabled more challenging substrate transformations to be addressed with greater selectivity and/or under increasingly mild conditions. Throughout, the importance and subtlety of ligand effects in palladium‐catalyzed cross‐coupling reactions are described, in an effort to inspire further development and understanding within the field of ancillary ligand design. 相似文献
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Design of New Ligands for the Palladium‐Catalyzed Arylation of α‐Branched Secondary Amines 下载免费PDF全文
Nathaniel H. Park Ekaterina V. Vinogradova Dr. David S. Surry Prof. Dr. Stephen L. Buchwald 《Angewandte Chemie (International ed. in English)》2015,54(28):8259-8262
In Pd‐catalyzed C? N cross‐coupling reactions, α‐branched secondary amines are difficult coupling partners and the desired products are often produced in low yields. In order to provide a robust method for accessing N‐aryl α‐branched tertiary amines, new catalysts have been designed to suppress undesired side reactions often encountered when these amine nucleophiles are used. These advances enabled the arylation of a wide array of sterically encumbered amines, highlighting the importance of rational ligand design in facilitating challenging Pd‐catalyzed cross‐coupling reactions. 相似文献
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Jing Hou Prof. Jian‐Hua Xie Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2015,54(21):6302-6305
A palladium‐catalyzed hydrocarboxylation of alkynes with formic acid has been developed. The method provides acrylic acid and derivatives in good yields with high regioselectivity without the need to handle toxic CO gas. 相似文献
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Sepideh Sharif Dr. Richard P. Rucker Dr. Nalin Chandrasoma Dr. David Mitchell Dr. Michael J. Rodriguez Dr. Robert D. J. Froese Prof. Michael G. Organ 《Angewandte Chemie (International ed. in English)》2015,54(33):9507-9511
A single set of reaction conditions for the palladium‐catalyzed amination of a wide variety of (hetero)aryl halides using primary alkyl amines has been developed. By combining the exceptionally high reactivity of the Pd‐PEPPSI‐IPentCl catalyst (PEPPSI=pyridine enhanced precatalyst preparation, stabilization, and initiation) with the soluble and nonaggressive sodium salt of BHT (BHT=2,6‐di‐tert‐butyl‐hydroxytoluene), both six‐ and five‐membered (hetero)aryl halides undergo efficient and selective amination. 相似文献
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Copper‐Catalyzed Coupling of Triaryl‐ and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations 下载免费PDF全文
Surendra Thapa Dr. Santosh K. Gurung Dr. Diane A. Dickie Prof. Dr. Ramesh Giri 《Angewandte Chemie (International ed. in English)》2014,53(43):11620-11624
An efficient copper(I)‐catalyzed coupling of triaryl and trialkylindium reagents with aryl iodides and bromides is reported. The reaction proceeds at low catalyst loadings (2 mol %) and generally only requires 0.33 equivalents of the triorganoindium reagent with respect to the aryl halide as all three organic nucleophilic moieties of the reagent are transferred to the products through consecutive transmetalations. The reaction tolerates a variety of functional groups and sterically hindered substrates. Furthermore, preliminary mechanistic studies that entailed the synthesis and characterization of potential reaction intermediates offered a glimpse of the elementary steps that constitute the catalytic cycle. 相似文献
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Tomohiro Sugahara Prof. Dr. Kei Murakami Prof. Dr. Hideki Yorimitsu Prof. Dr. Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2014,53(35):9329-9333
A combination of a palladium–NHC catalyst and potassium hexamethyldisilazide enables the amination of aryl sulfides with anilines to afford a wide variety of diarylamines. The reaction conditions are versatile enough for the reaction of even bulky ortho‐substituted aryl sulfides. This amination can be applied to the modular synthesis of N‐aryl carbazoles from the corresponding ortho‐bromothioanisoles. As aryl sulfoxides undergo extended Pummerer reactions to afford ortho‐substituted aryl sulfides, the Pummerer products are thus useful substrates for the amination to culminate in efficient syntheses of a 2‐anilinobenzothiophene and an indole as proof‐of‐principle of the utility of the extended Pummerer reaction/amination cascade. 相似文献
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Palladium‐Catalyzed Alkoxycarbonylation of Conjugated Dienes under Acid‐Free Conditions: Atom‐Economic Synthesis of β,γ‐Unsaturated Esters 下载免费PDF全文
Xianjie Fang Haoquan Li Dr. Ralf Jackstell Prof. Dr. Matthias Beller 《Angewandte Chemie (International ed. in English)》2014,53(34):9030-9034
Carbonylation reactions constitute important methodologies for the synthesis of all kinds of carboxylic acid derivatives. The development of novel and better catalysts for these transformations is of interest for both academic and industrial research. Here, a benign palladium‐based catalyst system for the alkoxycarbonylation of conjugated dienes under acid‐free conditions has been developed. This atom‐efficient transformation provides straightforward access to a variety of β,γ‐unsaturated esters in good to excellent yields and often with high selectivities. As an industrially relevant example the (formal) synthesis of dimethyl adipate and ε‐caprolactam from 1,3‐butadiene is demonstrated. 相似文献
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Copper‐Catalyzed Reductive Cross‐Coupling of Nonactivated Alkyl Tosylates and Mesylates with Alkyl and Aryl Bromides 下载免费PDF全文
Jing‐Hui Liu Chu‐Ting Yang Xiao‐Yu Lu Zhen‐Qi Zhang Ling Xu Mian Cui Xi Lu Bin Xiao Prof. Dr. Yao Fu Prof. Dr. Lei Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15334-15338
A copper‐catalyzed reductive cross‐coupling reaction of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides was developed. It provides a practical method for efficient and cost‐effective construction of aryl–alkyl and alkyl–alkyl C?C bonds with stereocontrol from readily available substrates. When used in an intramolecular fashion, the reaction enables convenient access to various substituted carbo‐ or heterocycles, such as 2,3‐dihydrobenzofuran and benzochromene derivatives. 相似文献
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A manganese‐catalyzed cross‐coupling reaction of thiols with aryl iodides, furnishing aryl thioethers in good to excellent yields has been reported; the system shows good functional group tolerance and enables the sterically demanding aryl iodides to couple with thiols. 相似文献
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Synthesis of Aryldiazoacetates through Palladium(0)‐Catalyzed Deacylative Cross‐Coupling of Aryl Iodides with Acyldiazoacetates 下载免费PDF全文
Fei Ye Chengpeng Wang Dr. Yan Zhang Prof. Dr. Jianbo Wang 《Angewandte Chemie (International ed. in English)》2014,53(43):11625-11628
Palladium(0)‐catalyzed deacylative cross‐coupling of aryl iodides and acyldiazocarbonyl compounds can be achieved at room temperature under mild reaction conditions. The coupling reaction represents a highly efficient and general method for the synthesis of aryldiazocarbonyl compounds, which have found wide and increasing applications as precursors for generating donor/acceptor‐substituted metallocarbenes. 相似文献
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Dr. Andrey Borzenko Nicolas L. Rotta‐Loria Preston M. MacQueen Christopher M. Lavoie Dr. Robert McDonald Prof. Dr. Mark Stradiotto 《Angewandte Chemie (International ed. in English)》2015,54(12):3773-3777
Structurally diverse (hetero)aryl chloride, bromide, and tosylate electrophiles were employed in the Ni‐catalyzed monoarylation of ammonia, including chemoselective transformations. The employed JosiPhos/[Ni(cod)2] catalyst system enables the use of commercially available stock solutions of ammonia, or the use of ammonia gas in these reactions, thereby demonstrating the versatility and potential scalability of the reported protocol. Proof‐of‐principle experiments established that air‐stable [(JosiPhos)NiCl2] precatalysts can be employed successfully in such transformations. 相似文献
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Chuanhu Lei Xiaojia Jin Jianrong Zhou 《Angewandte Chemie (International ed. in English)》2015,54(45):13397-13400
Three‐component couplings were achieved from common aryl halides, alkyl halides, and heteroarenes under palladium and norbornene co‐catalysis. The reaction forges hindered aryl–heteroaryl bonds and introduces ortho‐alkyl groups to aryl rings. Various heterocycles such as oxazoles, thiazoles and thiophenes underwent efficient coupling. The heteroarenes were deprotonated in situ by bases without the assistance of palladium catalysts. 相似文献
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Diaryl Sulfoxides from Aryl Benzyl Sulfoxides: A Single Palladium‐Catalyzed Triple Relay Process 下载免费PDF全文
Tiezheng Jia Dr. Ana Bellomo Dr. Sonia Montel Mengnan Zhang Kawtar EL Baina Bing Zheng Prof. Patrick J. Walsh 《Angewandte Chemie (International ed. in English)》2014,53(1):260-264
A novel approach to produce diaryl sulfoxides from aryl benzyl sulfoxides is reported. Optimization of the reaction conditions was performed using high‐throughput experimentation techniques. The [Pd(dba)2]/NiXantPhos catalyst system successfully promotes a triple relay process involving sulfoxide α‐arylation, C? S bond cleavage, and C? S bond formation. The byproduct benzophenone is formed by an additional palladium‐catalyzed process. It is noteworthy that palladium‐catalyzed benzylative C? S bond cleavage of sulfoxides is unprecedented. A wide range of aryl benzyl sulfoxides, as well as alkyl benzyl sulfoxides with various (hetero)aryl bromides were employed in the triple relay process in good to excellent yields (85–99 %). Moreover, aryl methyl sulfoxides, dibenzyl sulfoxides, and dimethylsulfoxide could be utilized to generate diaryl sulfoxides involving multiple catalytic cycles by a single catalyst. 相似文献