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铜催化下,以CH3CN和HOAc为混合溶剂,α,β-不饱和羧酸与1,1,1-三氟-2-碘乙烷(ICH2CF3)发生脱羧偶联反应合成了一系列三氟乙基取代烯烃,其结构经1H NMR、13C NMR和HR-MS确证。19F NMR分析显示该反应具有优良的立体选择性(E/Z最高为99/1),分离收率最高达82%。 相似文献
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利用密度泛函理论(DFT)计算研究了[Fe(MgBr)2]催化的邻氯苯乙稀与溴代苯基镁反应生成联芳化合物的交叉偶联反应的机理. 研究了两个机理. 机理A包括三个基本步骤: (I) 氧化[Fe(MgBr)2]生成[Ar-Fe(MgBr)],(II) 加成产生[Ar-(phenyl)-Fe(MgBr)2], (III) 还原消除回到[Fe(MgBr)2]. 机理B不形成[Ar-Fe(MgBr)]. 在第一步,溴代苯基镁在[Cl-Mg-Br]离解形成[Ar-Fe(MgBr)]之前直接进攻氧化加成后的中间体. 考虑溶剂效应后, 机理B优于机理A. 无论机理A还是机理B, 整个催化循环过程的决速步骤都是[Ar-(phenyl)-Fe(MgBr)2]的还原消除再生催化剂[Fe(MgBr)2]的步骤, 使用导体极化连续模型(CPCM)方法计算其在四氢呋喃溶剂中的吉布斯自由能(ΔGsol)是82.98 kJ·mol-1. 相似文献
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新反应、新试剂的发展是有机合成化学的重要研究内容,基于前期在α-氨基丙二腈合成方法学方面的工作基础,我们发展了一例铜催化的α-氨基丙二腈的脱氰氧代反应.通过将甲酰胺转化为α-氨基丙二腈后,借助其亲核属性来合成α-氨基丙二腈底物,而后将底物重新转化为酰胺,从而实现形式上的氨基甲酰负离子的亲核加成(取代)反应.该工作首次完成了形式上的甲酰胺碳原子的极性反转,实现了将α-氨基丙二腈作为氨基甲酰负离子替代物的反应新模式,为叔酰胺化合物的合成提供了新的思路和方法,且具有反应条件简单,底物适用性广及适合克级规模制备等特点. 相似文献
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Kai Yang Jiaqing Lu Dr. Liubo Li Prof. Sanzhong Luo Prof. Niankai Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202202370
An electrophotochemical dual metal-catalyzed protocol for decarboxylative arylation of simple aliphatic carboxylic acids with aryl halides is reported. The relative stabilities of catalytically active metal complexes simultaneously generated at anode and cathode are the key design elements for the success of this convergent paired electrolysis. This new electrophotocatalytic method is mild, robust, and most importantly, capable of accommodating simple primary aliphatic acids including acetic acid – ubiquitous and variegated structural motifs yet remain oddly challenging substrates – directly as native functional groups for decarboxylative C(sp2)−C(sp3) bond formation. 相似文献
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The exceptional versatility of carboxylic acids has been extensively exploited in organic synthesis across several decades. There has been a recent upsurge of radical decarboxylative transformations. The process can be initiated under mild conditions, and the resultant radicals have orthogonal reactivities to closed-shell species, thus providing immense opportunities for streamlining novel reactions. The use of free carboxylic acids is the most desirable owing to its high atom and step economy. Aiming to demonstrate the attractiveness of the strategy and to inspire chemists to tackle existing challenges, this review outlines the recent advances on radical decarboxylative functionalization of free carboxylic acids. 相似文献
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A Pd-catalyzed decarboxylative coupling of substituted benzoic acids with phenylboronic acid has been developed. Under the optimized conditions, a variety of substituted benzoic acids were found to undergo decarboxylative coupling with various phenylboronic acids to give the desired unsymmetrical biaryls in good yields.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
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Dr. Xi Lu Prof. Dr. Bin Xiao Prof. Dr. Lei Liu Prof. Dr. Yao Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11161-11164
Olefins and carboxylic acids are among the most important feedstock compounds. They are commonly found in natural products and drug molecules. We report a new reaction of nickel‐catalyzed decarboxylative olefin hydroalkylation, which provides a novel practical strategy for the construction of C(sp3)?C(sp3) bonds. This reaction can tolerate a variety of synthetically relevant functional groups and shows good chemo‐ and regioselectivity. It enables cross‐coupling of complex organic molecules containing olefin groups and carboxylic acid groups in a convergent fashion. 相似文献
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Dr. Kaitie C. Cartwright Ebbin Joseph Chelsea G. Comadoll Prof. Jon A. Tunge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(54):12454-12471
Recently, dual-catalytic strategies towards the decarboxylative elimination of carboxylic acids have gained attention. Our lab previously reported a photoredox/cobaloxime dual catalytic method that allows the synthesis of enamides and enecarbamates directly from N-acyl amino acids and avoids the use of any stoichiometric reagents. Further development, detailed herein, has improved upon this transformation's utility and further experimentation has provided new insights into the reaction mechanism. These new developments and insights are anticipated to aid in the expansion of photoredox/cobalt dual-catalytic systems. 相似文献
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Dr. Johanne Ling Dr. Antoine Bruneau-Voisine Dr. Guillaume Journot Prof. Gwilherm Evano 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(44):e202201356
A general copper-catalyzed carbonylative cross-coupling between amines and alkyl iodides is reported. Using a simple combination of catalytic amounts of copper(I) chloride and N,N,N’,N”,N”-pentamethyldiethylenetriamine in the presence of sodium hydroxide under carbon monoxide pressure, a broad range of alkyl iodides and amines can be efficiently coupled to the corresponding amides that are obtained in good to excellent yields. Notable features of this process – the first one relying on a base metal catalyst – include the availability and low cost of the catalytic system, its successful use with primary, secondary, tertiary alkyl iodides and all classes of amines – with no or limited competing nucleophilic substitution without CO incorporation – as well as its efficiency with complex alkyl iodides and amines. Mechanistic studies demonstrated that a radical pathway is operative and the key role of CO. 相似文献
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Decarboxylative Conjunctive Cross‐coupling of Vinyl Boronic Esters using Metallaphotoredox Catalysis
Riccardo S. Mega Vincent K. Duong Adam Noble Varinder K. Aggarwal 《Angewandte Chemie (International ed. in English)》2020,59(11):4375-4379
The synthesis of complex alkyl boronic esters through conjunctive cross‐coupling of vinyl boronic esters with carboxylic acids and aryl iodides is described. The reaction proceeds under mild metallaphotoredox conditions and involves an unprecedented decarboxylative radical addition/cross‐coupling cascade of vinyl boronic esters. Excellent functional‐group tolerance is displayed, and application of a range of carboxylic acids, including secondary α‐amino acids, and aryl iodides provides efficient access to highly functionalized alkyl boronic esters. The decarboxylative conjunctive cross‐coupling was also applied to the synthesis of sedum alkaloids. 相似文献