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1.
Shuai Xu Guojiao Wu Fei Ye Xi Wang Huan Li Xia Zhao Yan Zhang Jianbo Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(15):4752-4755
The copper(I)‐catalyzed alkylation of electron‐deficient polyfluoroarenes with N‐tosylhydrazones and diazo compounds has been developed. This reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of C(sp2) C(sp3) bonds with polyfluoroarenes through direct C H bond functionalization. Mechanistically, copper(I) carbene formation and subsequent migratory insertion are proposed as the key steps in the reaction pathway. 相似文献
2.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(43):13509-13513
The first oxidative C(sp3)−H/C(sp3)−H cross‐dehydrogenative coupling (CDC) reaction promoted by an internal oxidant is reported. This copper‐catalyzed CDC reaction of oxime acetates and trifluoromethyl ketones provides a simple and efficient approach towards 2‐trifluoromethyldihydropyrrol‐2‐ol derivatives in a highly diastereoselective manner by cascade C(sp3)−C(sp3) bond formation and cyclization. These products were further transformed into various significant and useful trifluoromethylated heterocyclic compounds, such as trifluoromethylated furan, thiophene, pyrrole, dihydropyridazine, and pyridazine derivatives. A trifluoromethylated analogue of an Aβ42 lowering agent was also synthesized smoothly. Preliminary mechanistic studies indicated that this reaction involves a copper(I)/copper(III) catalytic cycle with the oxime acetate acting as an internal oxidant. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(14):4003-4008
Reported herein is an exceptional chemoselective ring‐opening/C(sp3)−C(sp3) bond formation in the copper(I)‐catalyzed reaction of cyclopropanols with diazo esters. The conventional O−H insertion product is essentially suppressed by judicious choice of reaction conditions. DFT calculations provide insights into the reaction mechanism and the rationale for this unusual chemoselectivity. 相似文献
4.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(35):10691-10694
A copper‐catalyzed three‐component reaction of alkenes, acetonitrile, and sodium azide afforded γ‐azido alkyl nitriles by formation of one C(sp3)−C(sp3) bond and one C(sp3)−N bond. The transformation allows concomitant introduction of two highly versatile groups (CN and N3) across the double bond. A sequence involving the copper‐mediated generation of a cyanomethyl radical and its subsequent addition to an alkene, and a C(sp3)−N bond formation accounted for the reaction outcome. The resulting γ‐azido alkyl nitrile can be easily converted into 1,4‐diamines, γ‐amino nitriles, γ‐azido esters, and γ‐lactams of significant synthetic value. 相似文献
5.
Xiao‐Long Su Liu Ye Ji‐Jun Chen Xiao‐Dong Liu Sheng‐Peng Jiang Fu‐Li Wang Lin Liu Chang‐Jiang Yang Xiao‐Yong Chang Zhong‐Liang Li Qiang‐Shuai Gu Xin‐Yuan Liu 《Angewandte Chemie (International ed. in English)》2021,60(1):380-384
The development of enantioconvergent cross‐coupling of racemic alkyl halides directly with heteroarene C(sp2)?H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona‐alkaloid‐derived N,N,P‐ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)?H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α‐chiral alkylated azoles, such as 1,3,4‐oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4‐triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)?H bond and the involvement of alkyl radical species under the reaction conditions. 相似文献
6.
Dr. Zhaodong Li Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2018,57(40):13288-13292
Reported herein is an unprecedented copper‐catalyzed arylation of remote C(sp3)?H bonds. Stirring a trifluorotoluene solution of either N‐fluorocarboxamides or N‐fluorosulfonamides and arylboronic acids in the presence of a catalytic amount of copper(II) trifluoroacetylacetonate, 2,2′‐bipyridine, and sodium tert‐butoxide afforded the γ‐ and δ‐C(sp3)?H arylated carboxamides and sulfonamides, respectively, in good to high yields. Mechanistic studies indicate that the reaction might proceed through an amidyl radical generation, 1,5‐hydrogen atom transfer (HAT), and copper‐catalyzed cross‐coupling of the resulting carbon radical with arylboronic acids. 相似文献
7.
Alkenylation of C(sp3)−H Bonds by Zincation/Copper‐Catalyzed Cross‐Coupling with Iodonium Salts
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Dr. Chuan Liu Prof. Dr. Qiu Wang 《Angewandte Chemie (International ed. in English)》2018,57(17):4727-4731
α‐Vinylation of phosphonates, phosphine oxides, sulfones, sulfonamides, and sulfoxides has been achieved by selective C?H zincation and copper‐catalyzed C(sp3)?C(sp2) cross‐coupling reaction using vinylphenyliodonium salts. The vinylation transformation proceeds in high efficiency and stereospecificity under mild reaction conditions. This zincative cross‐coupling reaction represents a general alkenylation strategy, which is also applicable for α‐alkenylation of esters, amides, and nitriles in the synthesis of β,γ‐unsaturated carbonyl compounds. 相似文献
8.
Ala Bunescu Dr. Qian Wang Prof. Dr. Jieping Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14633-14636
A copper‐promoted oxyalkylation of alkenes with alkylnitriles has been developed. The protocol provides rapid access to phthalides (γ‐lactones) or isochromanones (δ‐lactones) via the formation of a C(sp3)?C(sp3) and a C(sp3)?O bond with the generation of up to two quaternary carbon atoms. Mechanistic studies suggest that this reaction is initiated by the formation of the C(sp3)?C(sp3) bond rather than the C(sp3)?O bond. Catalytic conditions were subsequently developed using carboxylic acid as an internal nucleophile. 相似文献
9.
Ligand‐Assisted Gold‐Catalyzed Cross‐Coupling with Aryldiazonium Salts: Redox Gold Catalysis without an External Oxidant
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Rong Cai Mei Lu Ellen Y. Aguilera Yumeng Xi Dr. Novruz G. Akhmedov Dr. Jeffrey L. Petersen Prof. Dr. Hao Chen Prof. Dr. Xiaodong Shi 《Angewandte Chemie (International ed. in English)》2015,54(30):8772-8776
Gold‐catalyzed C(sp)–C(sp2) and C(sp2)–C(sp2) cross‐coupling reactions are accomplished with aryldiazonium salts as the coupling partner. With the assistance of bpy ligand, gold(I) species were oxidized to gold(III) by diazonium without any external oxidants. Monitoring the reaction with NMR and ESI‐MS provided strong evidence for the nitrogen extrusion followed by AuIII reductive elimination as the key step. 相似文献
10.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(50):16229-16233
A rhodium(II)‐ or copper(I)‐catalyzed formal intramolecular carbene insertion into vinylic C(sp2)−H bonds is reported herein. This method provides straightforward access to 1H ‐indenes with high efficiency and excellent functional‐group compatibility. Mechanistically, the reaction is proposed to involve the following sequence: metal carbene formation, intramolecular nucleophilic addition of the double bond to the electron‐deficient carbene carbon atom, dearomatization, and finally a 1,5‐H shift. 相似文献
11.
Formation of C(sp2)–X bonds was carried out using a Fe3O4@SiO2‐copper(I) sucrose xanthate nanoparticle catalyst with the aid of the copper(I) xanthate moiety in the catalyst which was prepared from the reaction between sucrose and carbon disulfide through an alkaline medium via the traditional Zeise approach. Various techniques were employed for the characterization of these novel nanoparticles. Three sorts of heteroatoms, N, O and S, successfully underwent heteroatom arylation to produce secondary or tertiary amines, ethers and thioethers, respectively. 相似文献
12.
Runze Mao Jonathan Balon Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2018,57(41):13624-13628
Alkyl aryl ethers are an important class of compounds in medicinal and agricultural chemistry. Catalytic C(sp3)?O cross‐coupling of alkyl electrophiles with phenols is an unexplored disconnection strategy to the synthesis of alkyl aryl ethers, with the potential to overcome some of the major limitations of existing methods such as C(sp2)?O cross‐coupling and SN2 reactions. Reported here is a tandem photoredox and copper catalysis to achieve decarboxylative C(sp3)?O coupling of alkyl N‐hydroxyphthalimide (NHPI) esters with phenols under mild reaction conditions. This method was used to synthesize a diverse set of alkyl aryl ethers using readily available alkyl carboxylic acids, including many natural products and drug molecules. Complementarity in scope and functional‐group tolerance to existing methods was demonstrated. 相似文献
13.
Dr. Xuesong Wu Yan Zhao Dr. Guangwu Zhang Prof. Dr. Haibo Ge 《Angewandte Chemie (International ed. in English)》2014,53(14):3706-3710
The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper‐catalyzed sp3 C? H bond functionalization process. The reaction favors predominantly the C? H bonds of β‐methyl groups over the unactivated methylene C? H bonds. Moreover, a preference for activating sp3 C? H bonds of β‐methyl groups, via a five‐membered ring intermediate, over the aromatic sp2 C? H bonds was also observed in the cyclometalation step. Additionally, sp3 C? H bonds of unactivated secondary sp3 C? H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms. 相似文献
14.
Xu Bao Qian Wang Jieping Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(7):2161-2165
Under mild dual photoredox/copper catalysis, the reaction of N‐alkoxypyridinium salts with readily available silyl reagents (TMSN3, TMSCN, TMSNCS) afforded δ‐azido, δ‐cyano, and δ‐thiocyanato alcohols in high yields. The reaction went through a domino process involving alkoxy radical generation, 1,5‐hydrogen atom transfer (1,5‐HAT) and copper‐catalyzed functionalization of the resulting C‐centered radical. Conditions for catalytic enantioselective δ‐C(sp3)?H cyanation were also documented. 相似文献
15.
Zhen Wang Jizhi Ni Prof. Dr. Yoichiro Kuninobu Prof. Dr. Motomu Kanai 《Angewandte Chemie (International ed. in English)》2014,53(13):3496-3499
The first copper‐catalyzed intramolecular C(sp3)? H and C(sp2)? H oxidative amidation has been developed. Using a Cu(OAc)2 catalyst and an Ag2CO3 oxidant in dichloroethane solvent, C(sp3)? H amidation proceeded at a terminal methyl group, as well as at the internal benzylic position of an alkyl chain. This reaction has a broad substrate scope, and various β‐lactams were obtained in excellent yield, even on gram scale. Use of CuCl2 and Ag2CO3 under an O2 atmosphere in dimethyl sulfoxide, however, leads to 2‐indolinone selectively by C(sp2)? H amidation. Kinetic isotope effect (KIE) studies indicated that C? H bond activation is the rate‐determining step. The 5‐methoxyquinolyl directing group could be removed by oxidation. 相似文献
16.
《Angewandte Chemie (International ed. in English)》2017,56(38):11649-11652
A decarboxylative silylation of aliphatic N ‐hydroxyphthalimide (NHPI) esters using Si−B reagents as silicon pronucleophiles is reported. This C(sp3)−Si cross‐coupling is catalyzed by copper(I) and follows a radical mechanism, even with exclusion of light. Both primary and secondary alkyl groups couple effectively, whereas tertiary alkyl groups are probably too sterically hindered. The functional‐group tolerance is generally excellent, and α‐heteroatom‐substituted substrates also participate well. This enables, for example, the synthesis of α‐silylated amines starting from NHPI esters derived from α‐amino acids. The new method extends the still limited number of C(sp3)−Si cross‐couplings of unactivated alkyl electrophiles. 相似文献
17.
Synthesis of α‐Aryl Esters and Nitriles: Deaminative Coupling of α‐Aminoesters and α‐Aminoacetonitriles with Arylboronic Acids
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Guojiao Wu Yifan Deng Chaoqiang Wu Dr. Yan Zhang Prof. Dr. Jianbo Wang 《Angewandte Chemie (International ed. in English)》2014,53(39):10510-10514
Transition‐metal‐free synthesis of α‐aryl esters and nitriles using arylboronic acids with α‐aminoesters and α‐aminoacetonitriles, respectively, as the starting materials has been developed. The reaction represents a rare case of converting C(sp3)? N bonds into C(sp3)? C(sp2) bonds. The reaction conditions are mild, demonstrate good functional‐group tolerance, and can be scaled up. 相似文献
18.
Mechanism of Nickel(II)‐Catalyzed Oxidative C(sp2)−H/C(sp3)−H Coupling of Benzamides and Toluene Derivatives
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The Ni‐catalyzed C(sp2)?H/C(sp3)?H coupling of benzamides with toluene derivatives was recently successfully achieved with mild oxidant iC3F7I. Herein, we employ density functional theory (DFT) methods to resolve the mechanistic controversies. Two previously proposed mechanisms are excluded, and our proposed mechanism involving iodine‐atom transfer (IAT) between iC3F7I and the NiII intermediate was found to be more feasible. With this mechanism, the presence of a carbon radical is consistent with the experimental observation that (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) completely quenches the reaction. Meanwhile, the hydrogen‐atom abstraction of toluene is irreversible and the activation of the C(sp2)?H bond of benzamides is reversible. Both of these conclusions are in good agreement with Chatani's deuterium‐labeling experiments. 相似文献
19.
Amine‐Catalyzed Highly Regioselective and Stereoselective C(sp2)–C(sp2) Cross‐Coupling of Naphthols with trans‐α,β‐Unsaturated Aldehydes
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A metal‐free C(sp2)–C(sp2) cross‐coupling approach to highly congested (E)‐α‐naphtholylenals from simple naphthols and enals is described. The mild reaction conditions with pyridine hydrobromideperbromide (PHBP) as the bromination reagent in the presence of piperidine or diphenylprolinol trimethylsilyl (TMS) ether as promoters enable the process in good yields and with high chemoselectivity, regioselectivity, and stereoselectivity. The process involves an unprecedented pathway of in situ regioselective 4‐bromination of 1‐naphthols and the subsequent unusual aromatic nucleophilic substitution of the resulting 4‐bromo‐1‐naphthols with the α‐C(sp2) of enals through a Michael‐type Friedel–Crafts alkylation–dearomatization followed by a cyclopropanation ring‐opening cascade process. The noteworthy features of this strategy are highlighted by the highly efficient creation of a C(sp2)–C(sp2) bond from readily available unfunctionalized naphthols and enals catalyzed by non‐metal, readily available cyclic secondary amines under mild reaction conditions. 相似文献
20.
Prof. Dr. Daniel Solé Francesco Mariani Prof. Dr. M.‐Lluïsa Bennasar Dr. Israel Fernández 《Angewandte Chemie (International ed. in English)》2016,55(22):6467-6470
A palladium‐catalyzed carbene insertion into C(sp3)?H bonds leading to pyrrolidines was developed. The coupling reaction can be catalyzed by both Pd0 and PdII, is regioselective, and shows a broad functional group tolerance. This reaction is the first example of palladium‐catalyzed C(sp3)?C(sp3) bond assembly starting from diazocarbonyl compounds. DFT calculations revealed that this direct C(sp3)?H bond functionalization reaction involves an unprecedented concerted metalation–deprotonation step. 相似文献