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1.
Copper‐Catalyzed Enantioselective Arylative Desymmetrization of Prochiral Cyclopentenes with Diaryliodonium Salts
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Dr. Hua Wu Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2018,57(10):2721-2725
A copper‐catalyzed enantioselective arylative desymmetrization of prochiral cyclopentenes with diaryliodonium salts was developed. In the presence of a catalytic amount of a chiral copper–bisoxazoline complex, which was generated in situ, the reaction of 4‐substituted or 4,4‐disubstituted cyclopent‐1‐enes with diaryliodonium hexafluoroarsenates afforded the chiral arylated products in good yields with excellent enantioselectivity. A cyclohexyl‐containing Box ligand was essential for the high enantioselectivity. Transformation of the enantiomerically enriched adducts into other chiral building blocks is also documented. 相似文献
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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
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Stereoretentive Copper‐Catalyzed Directed Thioglycosylation of C(sp2)−H Bonds of Benzamides
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Amélie Chabrier Dr. Alexandre Bruneau Sara Benmahdjoub Dr. Belkacem Benmerad Dr. Sabrina Belaid Jean‐Daniel Brion Dr. Mouâd Alami Dr. Samir Messaoudi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):15006-15010
An efficient thioglycosylation of C(sp2)?H bonds with thiosugars has been established for the first time. Using only Cu(OAc)2?H2O as a catalyst and Ag2CO3 as an additive in DMSO, the protocol proved to have broad scope, and a variety of complex thioglycosides have been prepared in good yields with exclusive β‐selectivity. 相似文献
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《中国化学》2017,35(9):1378-1382
A simple and convenient copper‐catalyzed direct oxyphosphorylation of enamides with P(O)‐H compounds and dioxygen has been developed under mild conditions. This methodology can allow the synthesis of a series of valuable β ‐ketophosphine oxides/β ‐ketophosphonates in moderate to good yields with a broad substrate scope simply by using readily‐available starting materials. 相似文献
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Intermolecular Amination of Unactivated C(sp3)−H Bonds with Cyclic Alkylamines: Formation of C(sp3)−N Bonds through Copper/Oxygen‐Mediated C(sp3)−H/N−H Activation
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Quan Gou Yu‐Wen Yang Zi‐Ning Liu Prof. Jun Qin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16057-16061
The first example of intermolecular amination of unactivated C(sp3)?H bonds by cyclic alkylamines mediated by Cu(OAc)2/O2 is reported. This method avoids the use of benzoyloxyamines as the aminating reagent, which are normally prepared from alkylamines in extra steps. A variety of unnatural β2, 2‐amino acid analogues are synthesized by this simple and efficient procedure. This approach offers a solution to the previous unmet challenge of C(sp3)?H/N?H activation for the formation of C(sp3)?N bonds. 相似文献
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Copper‐Mediated Aromatic 1,1‐Difluoroethylation with (1,1‐Difluoroethyl)trimethylsilane (TMSCF2CH3)
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Xinjin Li Dr. Jingwei Zhao Yunze Wang Jian Rong Dr. Mingyou Hu Dr. Dingben Chen Pan Xiao Dr. Chuanfa Ni Prof. Dr. Limin Wang Prof. Dr. Jinbo Hu 《化学:亚洲杂志》2016,11(12):1789-1792
A new method for the formation of 1,1‐difluoroethyl copper species (“CuCF2CH3”) with 1,1‐difluoroethylsilane (TMSCF2CH3) has been developed. The “CuCF2CH3” species can be applied to the efficient 1,1‐difluoroethylation of diaryliodonium salts under mild conditions, affording (1,1‐difluoroethyl)arenes in good to excellent yields. This convenient procedure tolerates a wide range of functional groups and thus serves as a practical synthetic tool for the introduction of CF2CH3 group(s) into complex molecules. 相似文献
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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
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Hans Sterckx Bndicte Morel Bert U. W. Maes 《Angewandte Chemie (International ed. in English)》2019,58(24):7946-7970
Oxidation reactions are a key technology to transform hydrocarbons from petroleum feedstock into chemicals of a higher oxidation state, allowing further chemical transformations. These bulk‐scale oxidation processes usually employ molecular oxygen as the terminal oxidant as at this scale it is typically the only economically viable oxidant. The produced commodity chemicals possess limited functionality and usually show a high degree of symmetry thereby avoiding selectivity issues. In sharp contrast, in the production of fine chemicals preference is still given to classical oxidants. Considering the strive for greener production processes, the use of O2, the most abundant and greenest oxidant, is a logical choice. Given the rich functionality and complexity of fine chemicals, achieving regio/chemoselectivity is a major challenge. This review presents an overview of the most important catalytic systems recently described for aerobic oxidation, and the current insight in their reaction mechanism. 相似文献
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Stephen Hyde Dr. Janis Veliks Dr. Benoît Liégault Dr. David Grassi Dr. Marc Taillefer Prof. Véronique Gouverneur 《Angewandte Chemie (International ed. in English)》2016,55(11):3785-3789
Copper‐catalyzed Si?H, B?H, P?H, S?H, and N?H insertion reactions of 2,2,2‐trifluoro‐1‐diazoethane and 1‐aryl 2,2,2‐trifluorodiazoethanes generated a large number of new fluorine‐containing chemical entities for medicinal chemists. With selected Si?H and B?H insertion reactions, we demonstrate successful extension to asymmetric catalysis. 相似文献
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Tosylhydrazones are a kind of labile and highly reactive compounds, which are apt to be transformed into reactive diazo compounds and then into extremely reactive carbenes under the basic condition. In order to fulfil the valuable C‐N coupling reaction, diaryliodonium salts are evaluated and prove to be a class of efficient electrophiles. The reaction with ligand‐free copper salt as catalyst shows a wide range of substrate scope. A plausible mechanism is proposed. 相似文献
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Access to 2‐Arylindoles via Decarboxylative C−C Coupling in Aqueous Medium and to Heteroaryl Carboxylates under Base‐Free Conditions using Diaryliodonium Salts
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Easily accessible heteroaromatic carboxylic acids and diaryliodonium salts were successfully employed to construct valuable 2‐arylindoles and heteroaryl carboxylates in a regioselective fashion. C2‐arylated indoles were produced using a Pd‐catalyzed decarboxylative strategy in water without any base, oxidant, or ligand. Heteroaryl carboxylates were prepared under metal and base‐free conditions. This protocol was successfully utilized to synthesize Paullone, a cyclin‐dependent kinase (CDK) inhibitor. 相似文献
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《Angewandte Chemie (International ed. in English)》2017,56(35):10582-10586
The nucleophilic iron complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular amination of unactivated C(sp3)−H bonds in alkylaryl azides, which results in the formation of substituted indoline and tetrahydroquinoline derivatives. 相似文献
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Harekrishna Sahoo Mallu Kesava Reddy Isai Ramakrishna Dr. Mahiuddin Baidya 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1592-1596
A copper‐catalyzed 8‐amide chelation‐induced remote C?H amination of quinolines has been developed. This direct amination with readily available azodicarboxylates proceeded with perfect C5‐regioselectivity offering amino‐substituted 8‐aminoquinolines, important bioactive molecular scaffolds, in very high yields (up to 96 %). A single‐electron transfer (SET)‐mediated mechanism with kH/kD=1.1 was proposed after trapping of the radical intermediate. 相似文献
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Copper‐Catalyzed Regioselective Cascade Alkylation and Cyclocondensation of Quinoline N‐Oxides with Diazo Esters: Direct Access to Conjugated π‐Systems
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Aniruddha Biswas Ujjwal Karmakar Arun Pal Dr. Rajarshi Samanta 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(39):13826-13830
An inexpensive copper‐catalyzed cascade regioselective alkylation, followed by cyclocondensation of quinoline N‐oxides with α‐diazo esters has been achieved successfully to provide heteroarene‐containing conjugated π‐systems. The developed method is simple, straightforward, and economical with a broad range of substrate scope. The dual role of copper catalyst in the C?H bond functionalization and in Lewis acid‐promoted cyclization was explored. 相似文献
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Copper‐Catalyzed Radical/Radical CH/PH Cross‐Coupling: α‐Phosphorylation of Aryl Ketone O‐Acetyloximes
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Jie Ke Yuliang Tang Hong Yi Yali Li Yongde Cheng Chao Liu Prof. Aiwen Lei 《Angewandte Chemie (International ed. in English)》2015,54(22):6604-6607
The selective radical/radical cross‐coupling of two different organic radicals is a great challenge due to the inherent activity of radicals. In this paper, a copper‐catalyzed radical/radical C? H/P? H cross‐coupling has been developed. It provides a radical/radical cross‐coupling in a selective manner. This work offers a simple way toward β‐ketophosphonates by oxidative coupling of aryl ketone o‐acetyloximes with phosphine oxides using CuCl as catalyst and PCy3 as ligand in dioxane under N2 atmosphere at 130 °C for 5 h, and yields ranging from 47 % to 86 %. The preliminary mechanistic studies by electron paramagnetic resonance (EPR) showed that, 1) the reduction of ketone o‐acetyloximes generates iminium radicals, which could isomerize to α‐sp3‐carbon radical species; 2) phosphorus radicals were generated from the oxidation of phosphine oxides. Various aryl ketone o‐acetyloximes and phosphine oxides were suitable for this transformation. 相似文献
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Xueling Mo Bin Chen Guozhu Zhang 《Angewandte Chemie (International ed. in English)》2020,59(33):13998-14002
An asymmetric copper‐catalyzed Sonogashira type coupling between alkynes and α‐bromoamides has been developed. This method represents a facile approach to synthetically useful β, γ‐alkynyl amides from two readily available starting materials in a highly enantioselective manner. A Bisoxazoline diphenylanaline (BOPA) serves as the effective chiral ligand. Preliminary mechanistic studies support the formation of alkyl radical species . 相似文献