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1.
Zhouyang Yin Huan Pang Xuefeng Guo Honghong Lin Michelle Muzzio Mengqi Shen Kecheng Wei Chao Yu Paul Williard Shouheng Sun 《Angewandte Chemie (International ed. in English)》2020,59(37):15933-15936
An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 m KHCO3 solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C?C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods. 相似文献
2.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(42):13283-13286
The construction of all C(sp3) quaternary centers has been successfully achieved under Ni‐catalyzed cross‐electrophile coupling of allylic carbonates with unactivated tertiary alkyl halides. For allylic carbonates bearing C1 or C3 substituents, the reaction affords excellent regioselectivity through the addition of alkyl groups to the unsubstituted allylic carbon terminus. The allylic alkylation method also exhibits excellent functional‐group compatibility, and delivers the products with high E selectivity. 相似文献
3.
Nickel‐ and Photoredox‐Catalyzed Cross‐Coupling Reactions of Aryl Halides with 4‐Alkyl‐1,4‐dihydropyridines as Formal Nucleophilic Alkylation Reagents 下载免费PDF全文
Dr. Kazunari Nakajima Sunao Nojima Prof. Dr. Yoshiaki Nishibayashi 《Angewandte Chemie (International ed. in English)》2016,55(45):14106-14110
A combination of nickel and photoredox catalysts promoted novel cross‐coupling reactions of aryl halides with 4‐alkyl‐1,4‐dihydropyridines. 4‐Alkyl‐1,4‐dihydropyridines act as formal nucleophilic alkylation reagents through a photoredox‐catalyzed carbon–carbon (C?C) bond‐cleavage process. The present strategy provides an alternative to classical carbon‐centered nucleophiles, such as organometallic reagents. 相似文献
4.
Pd‐Catalyzed Regioselective Activation of gem‐Difluorinated Cyclopropanes: A Highly Efficient Approach to 2‐Fluorinated Allylic Scaffolds 下载免费PDF全文
Jun Xu Ebrahim‐Alkhalil Ahmed Bin Xiao Qian‐Qian Lu Yun‐Long Wang Chu‐Guo Yu Prof. Yao Fu 《Angewandte Chemie (International ed. in English)》2015,54(28):8231-8235
An unprecedented Pd‐catalyzed regioselective activation of gem‐difluorinated cyclopropanes induced by C? C bond cleavage is reported. It provides a general and efficient access to a variety of 2‐fluoroallylic amines, ethers, esters, and alkylation products in high Z‐selectivity, which are important skeletons in many biologically active molecules. In addition, the transformation represents the first general application of gem‐difluorinated cyclopropanes as reaction partners in transition‐metal‐catalyzed cross‐coupling reaction. 相似文献
5.
Avijit Hazra Mitchell T. Lee Justin F. Chiu Prof. Gojko Lalic 《Angewandte Chemie (International ed. in English)》2018,57(19):5492-5496
We have developed a photoinduced copper‐catalyzed alkylation of terminal alkynes with primary, secondary, or tertiary alkyl iodides as electrophiles. The reaction has a broad substrate scope and can be successfully performed in the presence of ester, nitrile, aryl halide, ketone, sulfonamide, epoxide, alcohol, and amide functional groups. The alkylation is promoted by blue light (λ≈450 nm) and proceeds at room temperature in the absence of any additional metal catalysts. The use of a terpyridine ligand is essential for the success of the reaction and is shown to prevent photoinduced copper‐catalyzed polymerization of the starting materials. 相似文献
6.
Dr. Ramasamy Jayarajan Jayabrata Das Sukdev Bag Rajdip Chowdhury Prof. Dr. Debabrata Maiti 《Angewandte Chemie (International ed. in English)》2018,57(26):7659-7663
Arenes containing conformationally flexible long alkyl chains have been successfully functionalized at the meta‐position. Good to excellent meta selectivity is achieved for systems with up to 20 atoms between the target C?H bond and the coordinating heteroatom of the directing group. The palladium‐catalyzed functionalization reactions include alkylation, cyanation, olefination, and acetoxylation. The meta selectivity is exclusively governed by the design of flexible pyrimidine‐based scaffolds. 相似文献
7.
Jeffrey A. Boerth Joshua R. Hummel Prof. Dr. Jonathan A. Ellman 《Angewandte Chemie (International ed. in English)》2016,55(41):12650-12654
A highly stereoselective three‐component C(sp2)?H bond addition across alkene and polarized π‐bonds is reported for which CoIII catalysis was shown to be much more effective than RhIII. The reaction proceeds at ambient temperature with both aryl and alkyl enones employed as efficient coupling partners. Moreover, the reaction exhibits extremely broad scope with respect to the aldehyde input; electron rich and poor aromatic, alkenyl, and branched and unbranched alkyl aldehydes all couple in good yield and with high diastereoselectivity. Multiple directing groups participate in this transformation, including pyrazole, pyridine, and imine functional groups. Both aromatic and alkenyl C(sp2)?H bonds undergo the three‐component addition cascade, and the alkenyl addition product can readily be converted into diastereomerically pure five‐membered lactones. Additionally, the first asymmetric reactions with CoIII‐catalyzed C?H functionalization are demonstrated with three‐component C?H bond addition cascades employing N‐tert‐butanesulfinyl imines. These examples represent the first transition metal catalyzed C?H bond additions to N‐tert‐butanesulfinyl imines, which are versatile and extensively used intermediates for the asymmetric synthesis of amines. 相似文献
8.
Density Functional Theory Mechanistic Study of Boron‐Catalyzed N‐Alkylation of Amines with Formic Acid: Formic Acid Activation by Silylation Reaction 下载免费PDF全文
New methodology for the alkylation of amines is an intriguing issue in both academia and industry. Recently, several groups reported the metal‐free B(C6F5)3‐catalyzed N‐alkylation of amines, but the mechanistic details of these important reactions are unclear. Herein, a computational study was performed to elucidate the mechanism of the N‐alkylation of amines with formic acid catalyzed by the Lewis acid B(C6F5)3 in the presence of hydrosilane. We found that the reaction started with the activation of formic acid through a novel model. Then, the high electrophilicity of the C center of the formic acid unit and the nucleophilic character of the amine resulted in a C?N coupling reaction. Finally, two sequential silyl‐group and H? transfer steps occurred to generate the final product. Upon comparing the reaction barrier and the hydrogenation of indole, our mechanism is more favorable than that proposed by the group of Yu and Fu. 相似文献
9.
Rhodium(I)‐Catalyzed Sequential C(sp)C(sp3) and C(sp3)C(sp3) Bond Formation through Migratory Carbene Insertion 下载免费PDF全文
Ying Xia Sheng Feng Zhen Liu Dr. Yan Zhang Prof. Dr. Jianbo Wang 《Angewandte Chemie (International ed. in English)》2015,54(27):7891-7894
A RhI‐catalyzed three‐component reaction of tert‐propargyl alcohol, diazoester, and alkyl halide has been developed. This reaction can be considered as a carbene‐involving sequential alkyl and alkynyl coupling, in which C(sp)? C(sp3) and C(sp3)? C(sp3) bonds are built successively on the carbenic carbon atom. The RhI‐carbene migratory insertion of an alkynyl moiety and subsequent alkylation are proposed to account for the two separate C? C bond formations. This reaction provides an efficient and tunable method for the construction of all‐carbon quaternary center. 相似文献
10.
Ying Xia Sheng Feng Zhen Liu Yan Zhang Jianbo Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(27):8002-8005
A RhI‐catalyzed three‐component reaction of tert‐propargyl alcohol, diazoester, and alkyl halide has been developed. This reaction can be considered as a carbene‐involving sequential alkyl and alkynyl coupling, in which C(sp) C(sp3) and C(sp3) C(sp3) bonds are built successively on the carbenic carbon atom. The RhI‐carbene migratory insertion of an alkynyl moiety and subsequent alkylation are proposed to account for the two separate C C bond formations. This reaction provides an efficient and tunable method for the construction of all‐carbon quaternary center. 相似文献
11.
Soyoung Park Hiroshi Sugiyama 《Angewandte Chemie (International ed. in English)》2010,49(23):3870-3878
Stereoselective hybrid systems based on metal‐assisted catalysis with a chiral biomacromolecule form an attractive research area for the synthesis of enantiomerically pure compounds. Although various methods are available for this purpose, most rely on the use of enzymes, proteins, or RNA. The application of DNA‐based hybrid catalysts for enantioselective synthesis emerged only a few years ago. DNA‐based hybrid catalysts have been self‐assembled from DNA and a metal complex with a specific ligand through supramolecular or covalent anchoring strategies and have demonstrated high stereoselectivity and rate enhancement in Lewis acid catalyzed reactions, such as Diels–Alder, Michael addition, and Friedel–Crafts reactions. For these reactions, cheap and commercially available salmon testes DNA has generally been used. In this Minireview, we summarize recent developments in the area of asymmetric catalysis with DNA‐based hybrid catalysts. 相似文献
12.
Ren‐Ming Hu Dong‐Yang Han Ning Li Jie Huang Yu Feng Da‐Zhen Xu 《Angewandte Chemie (International ed. in English)》2020,59(10):3876-3880
Presented herein is the first direct alkylation and hydroxylation reaction between two different C(sp3)?H bonds, indolin‐2‐ones and alkyl‐substituted N‐heteroarenes, through an oxidative cross‐coupling reaction. The reaction is catalyzed by a simple iron salt under mild ligand‐free and base‐free conditions. The reaction is environmentally benign, employs air (molecular oxygen) as the terminal oxidant and oxygen source for the synthesis of O‐containing compounds, and produces only water as the byproduct. 相似文献
13.
Zheng‐Jian Wu Feng Su Weidong Lin Jinshuai Song Ting‐Bin Wen Hui‐Jun Zhang Hai‐Chao Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):16926-16930
Transition metal catalyzed C?H phosphorylation remains an unsolved challenge. Reported methods are generally limited in scope and require stoichiometric silver salts as oxidants. Reported here is an electrochemically driven RhIII‐catalyzed aryl C?H phosphorylation reaction that proceeds through H2 evolution, obviating the need for stoichiometric metal oxidants. The method is compatible with a variety of aryl C?H and P?H coupling partners and particularly useful for synthesizing triarylphosphine oxides from diarylphosphine oxides, which are often difficult coupling partners for transition metal catalyzed C?H phosphorylation reactions. Experimental results suggest that the mechanism responsible for the C?P bond formation involves an oxidation‐induced reductive elimination process. 相似文献
14.
Lei Dai Zi‐Hao Xia Yuan‐Yuan Gao Zhong‐Hua Gao Song Ye 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18292-18298
The merging of photoredox catalysis and N‐heterocyclic carbene (NHC) catalysis for γ‐ and ?‐alkylation of enals with alkyl radicals was developed. The alkylation reaction of γ‐oxidized enals with alkyl halides worked well for the synthesis γ‐multisubstituted‐α,β‐unsaturated esters, including those with challenging vicinal all‐carbon quaternary centers. The synthesis of ?‐multisubstituted‐α,β‐γ,δ‐diunsaturated esters by an unprecedented NHC‐catalyzed ?‐functionalization was also established. 相似文献
15.
Sina Rösler Michael Ertl Dr. Torsten Irrgang Prof. Dr. Rhett Kempe 《Angewandte Chemie (International ed. in English)》2015,54(50):15046-15050
The implementation of inexpensive, Earth‐abundant metals in typical noble‐metal‐mediated chemistry is a major goal in homogeneous catalysis. A sustainable or green reaction that has received a lot of attention in recent years and is preferentially catalyzed by Ir or Ru complexes is the alkylation of amines by alcohols. It is based on the borrowing hydrogen or hydrogen autotransfer concept. Herein, we report on the Co‐catalyzed alkylation of aromatic amines by alcohols. The reaction proceeds under mild conditions, and selectively generates monoalkylated amines. The observed selectivity allows the synthesis of unsymmetrically substituted diamines. A novel Co complex stabilized by a PN5P ligand catalyzes the reactions most efficiently. 相似文献
16.
Fang Zhou Yao Zhang Xianfeng Xu Shaolin Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(6):1768-1772
Reported here is a terminal‐selective, remote asymmetric hydroalkylation of olefins with racemic α‐bromo amides. The reaction proceeds by NiH‐catalyzed alkene isomerization and subsequent alkylation reaction, and can enantioconvergently introduce an unsymmetrical secondary alkyl group from a racemic α‐bromo amide onto a terminal C(sp3)?H position along the hydrocarbon chain of the alkene. This mild process affords a range of structurally diverse chiral α‐alkylalkanoic amides in excellent yields, and high regio‐ and enantioselectivities. In addition, the synthetic utility of this protocol is further highlighted by the regioconvergent conversion of industrial raw materials of isomeric olefin mixtures into enantioriched α‐alkylalkanoic amides on large scale. 相似文献
17.
Cross-coupling reactions have become indispensable tools for creating carbon-carbon (or heteroatom) bonds in organic synthesis. Like in other important transition metal catalyzed reactions, such as metathesis, addition, and polymerization, unsaturated compounds are usually employed as substrates for cross-coupling reactions. However during the past decade, a great deal of effort has been devoted to the use of alkyl halides as saturated compounds in cross-coupling reactions, which has resulted in significant progress in this undeveloped area by introducing new effective ligands. Many useful catalytic systems are now available for synthetic transformations based on C(sp(3))-C(sp(3)), C(sp(3))-C(sp(2)) and C(sp(3))-C(sp) bond formation as complementary methods to conventional C(sp(2))-C(sp(2)), C(sp(2))-C(sp) and C(sp)-C(sp) coupling. This tutorial review summarizes recent advances in cross-coupling reactions of alkyl halides and pseudohalides catalyzed by a palladium complex. 相似文献
18.
Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron‐Catalyzed Reductive anti‐Carbozincation of Terminal Alkynes and Base‐Metal‐Catalyzed Negishi Cross‐Coupling 下载免费PDF全文
Dr. Chi Wai Cheung Prof. Dr. Xile Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18439-18444
The stereoselective synthesis of trisubstituted alkenes is challenging. Here, we show that an iron‐catalyzed anti‐selective carbozincation of terminal alkynes can be combined with a base‐metal‐catalyzed cross‐coupling to prepare trisubstituted alkenes in a one‐pot reaction and with high regio‐ and stereocontrol. Cu‐, Ni‐, and Co‐based catalytic systems are developed for the coupling of sp‐, sp2‐, and sp3‐hybridized carbon electrophiles, respectively. The method encompasses a large substrate scope, as various alkynyl, aryl, alkenyl, acyl, and alkyl halides are suitable coupling partners. Compared with conventional carbometalation reactions of alkynes, the current method avoids pre‐made organometallic reagents and has a distinct stereoselectivity. 相似文献
19.
1,2,3‐Triazoles are unique heterocycles with intriguing physical properties that allow not only the coordination to metals, but also the establishment of supramolecular interactions based on their polarized C?H bonds. In this account, an extensive work of our group on the design and application of 1,2,3‐triazole catalysts is covered. Initially, a family of BINOL triazoles (Click‐BINOLs) was synthesized and employed in model test reactions in asymmetric metal catalysis such as the Ti‐catalyzed addition of alkylzinc reagents to aldehydes. The evolution from the Click‐BINOLs to a novel class of triazole‐based anion‐binding organocatalysts is further discussed. Consequently, these catalysts were successfully applied in alkylation reactions, as well as asymmetric dearomatizations of diverse N‐heteroarenes. 相似文献
20.
Koji Takizawa Tomoyuki Sekino Shunta Sato Tatsuhiko Yoshino Masahiro Kojima Shigeki Matsunaga 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9297-9301
Co‐catalyzed allylic substitution reactions have received little attention, arguably because of the lack of any known advantage of Co catalysis over either Rh or Ir catalysis. Described here is a general and regioselective Co‐catalyzed allylic alkylation using an in situ catalyst activation by organophotoredox catalysis. This noble‐metal‐free catalytic system exhibits unprecedentedly high reactivities and regioselectivities for the allylation with an allyl sulfone, for the first time, representing the unique synthetic utility of the Co‐catalyzed method compared to the related Rh‐ and Ir‐catalyzed reactions. 相似文献