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1.
Copper‐Catalyzed (2+1) Annulation of Acetophenones with Maleimides: Direct Synthesis of Cyclopropanes 下载免费PDF全文
Srimanta Manna Dr. Andrey P. Antonchick 《Angewandte Chemie (International ed. in English)》2015,54(49):14845-14848
A practical copper‐catalyzed direct oxidative cyclopropanation of electron‐deficient alkenes with acetophenone derivatives is reported. The dehydrogenative annulation involves a double C? H bond functionalization at the α‐position of the ketone using di‐tert‐butyl peroxide as oxidant. The broad scope of the reaction and excellent functional‐group tolerance is demonstrated for the stereoselective synthesis of fused cyclopropanes. The developed transformation revealed an unprecedented reactivity for copper‐catalyzed processes. 相似文献
2.
2,4‐Dinitrophenol‐Catalyzed α‐C(sp3)−H and C(sp)−H Bond Functionalization of Cyclic Amines and Alkynes: Highly Regio‐/Diastereoselective Synthesis of α‐Alkynyl‐3‐Amino‐2‐Oxindoles 下载免费PDF全文
Dr. Mukesh Kumar Banni P. Kaur Prof. Swapandeep S Chimni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):9948-9952
A transition‐metal‐ and oxidant‐free DNP (2,4‐dinitrophenol)‐catalyzed atom‐economical regio‐ and diastereoselective synthesis of monofunctionalized α‐alkynyl‐3‐amino‐2‐oxindole derivatives by C?H bond functionalization of cyclic amines and alkynes with indoline‐2,3‐diones has been developed. This cascade event sequentially involves the reductive amination of indoline‐2,3‐dione by imine formation and cross coupling between C(sp3)?H and C(sp)?H of the cyclic amines and alkynes. This reaction offers an efficient and attractive pathway to different types of α‐alkynyl‐3‐amino‐2‐oxindole derivatives in good yields with a wide tolerance of functional groups. The salient feature of this methodology is that it completely suppresses the homocoupling of alkynes. To the best of our knowledge, this is the first example of a DNP‐catalyzed metal‐free direct C(sp3)?H and C(sp)?H bond functionalization providing biologically active α‐alkynyl‐3‐amino‐2‐oxindole scaffolds. 相似文献
3.
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
4.
Jian He Heng Jiang Ryosuke Takise Ru‐Yi Zhu Dr. Gang Chen Prof. Dr. Hui‐Xiong Dai Dr. T. G. Murali Dhar Dr. Jun Shi Dr. Hao Zhang Dr. Peter T. W. Cheng Prof. Dr. Jin‐Quan Yu 《Angewandte Chemie (International ed. in English)》2016,55(2):785-789
A quinoline‐based ligand effectively promotes the palladium‐catalyzed borylation of C(sp3)? H bonds. Primary β‐C(sp3)? H bonds in carboxylic acid derivatives as well as secondary C(sp3)? H bonds in a variety of carbocyclic rings, including cyclopropanes, cyclobutanes, cyclopentanes, cyclohexanes, and cycloheptanes, can thus be borylated. This directed borylation method complements existing iridium(I)‐ and rhodium(I)‐catalyzed C? H borylation reactions in terms of scope and operational conditions. 相似文献
5.
Complementary Strategies for Directed C(sp3)−H Functionalization: A Comparison of Transition‐Metal‐Catalyzed Activation,Hydrogen Atom Transfer,and Carbene/Nitrene Transfer 下载免费PDF全文
John C. K. Chu Prof. Tomislav Rovis 《Angewandte Chemie (International ed. in English)》2018,57(1):62-101
The functionalization of C(sp3)?H bonds streamlines chemical synthesis by allowing the use of simple molecules and providing novel synthetic disconnections. Intensive recent efforts in the development of new reactions based on C?H functionalization have led to its wider adoption across a range of research areas. This Review discusses the strengths and weaknesses of three main approaches: transition‐metal‐catalyzed C?H activation, 1,n‐hydrogen atom transfer, and transition‐metal‐catalyzed carbene/nitrene transfer, for the directed functionalization of unactivated C(sp3)?H bonds. For each strategy, the scope, the reactivity of different C?H bonds, the position of the reacting C?H bonds relative to the directing group, and stereochemical outcomes are illustrated with examples in the literature. The aim of this Review is to provide guidance for the use of C?H functionalization reactions and inspire future research in this area. 相似文献
6.
Site‐Selective δ‐C(sp3)−H Alkylation of Amino Acids and Peptides with Maleimides via a Six‐Membered Palladacycle 下载免费PDF全文
Bei‐Bei Zhan Ya Li Jing‐Wen Xu Xing‐Liang Nie Dr. Jun Fan Liang Jin Prof. Dr. Bing‐Feng Shi 《Angewandte Chemie (International ed. in English)》2018,57(20):5858-5862
The site‐selective functionalization of unactivated C(sp3)?H bonds remains one of the greatest challenges in organic synthesis. Herein, we report on the site‐selective δ‐C(sp3)?H alkylation of amino acids and peptides with maleimides via a kinetically less favored six‐membered palladacycle in the presence of more accessible γ‐C(sp3)?H bonds. Experimental studies revealed that C?H bond cleavage occurs reversibly and preferentially at γ‐methyl over δ‐methyl C?H bonds while the subsequent alkylation proceeds exclusively at the six‐membered palladacycle that is generated by δ‐C?H activation. The selectivity can be explained by the Curtin–Hammett principle. The exceptional compatibility of this alkylation with various oligopeptides renders this procedure valuable for late‐stage peptide modifications. Notably, this process is also the first palladium(II)‐catalyzed Michael‐type alkylation reaction that proceeds through C(sp3)?H activation. 相似文献
7.
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
8.
Dr. Xuesong Wu Yan Zhao Dr. Guangwu Zhang Prof. Dr. Haibo Ge 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(14):3780-3784
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
9.
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
10.
Dr. Xuesong Wu Yan Zhao Prof. Dr. Haibo Ge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9530-9533
Intramolecular dehydrogenative cyclization of aliphatic amides was achieved on unactivated sp3 carbon atoms by a nickel‐catalyzed C?H bond functionalization process with the assistance of a bidentate directing group. The reaction favors the C?H bonds of β‐methyl groups over the γ‐methyl or β‐methylene groups. Additionally, a predominant preference for the β‐methyl C?H bonds over the aromatic sp2 C?H bonds was observed. Moreover, this process also allows for the effective functionalization of benzylic secondary sp3 C?H bonds. 相似文献
11.
He Wang Guodong Tang Xingwei Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(44):13241-13244
Nitrogenation by direct functionalization of C H bonds represents an important strategy for constructing C N bonds. Rhodium(III)‐catalyzed direct amidation of unactivated C(sp3) H bonds is rare, especially under mild reaction conditions. Herein, a broad scope of C(sp3) H bonds are amidated under rhodium catalysis in high efficiency using 3‐substituted 1,4,2‐dioxazol‐5‐ones as the amide source. The protocol broadens the scope of rhodium(III)‐catalyzed C(sp3) H activation chemistry, and is applicable to the late‐stage functionalization of natural products. 相似文献
12.
He Wang Guodong Tang Xingwei Li 《Angewandte Chemie (International ed. in English)》2015,54(44):13049-13052
Nitrogenation by direct functionalization of C H bonds represents an important strategy for constructing C N bonds. Rhodium(III)‐catalyzed direct amidation of unactivated C(sp3) H bonds is rare, especially under mild reaction conditions. Herein, a broad scope of C(sp3) H bonds are amidated under rhodium catalysis in high efficiency using 3‐substituted 1,4,2‐dioxazol‐5‐ones as the amide source. The protocol broadens the scope of rhodium(III)‐catalyzed C(sp3) H activation chemistry, and is applicable to the late‐stage functionalization of natural products. 相似文献
13.
Copper(I)‐Catalyzed Alkylation of Polyfluoroarenes through Direct CH Bond Functionalization 下载免费PDF全文
Shuai Xu Guojiao Wu Fei Ye Xi Wang Huan Li Xia Zhao Dr. Yan Zhang Prof. Dr. Jianbo Wang 《Angewandte Chemie (International ed. in English)》2015,54(15):4669-4672
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
14.
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
15.
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
16.
Dual C(sp3)−H Bond Functionalization of N‐Heterocycles through Sequential Visible‐Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions 下载免费PDF全文
Dr. Guo‐Qiang Xu Ji‐Tao Xu Zhi‐Tao Feng Hui Liang Prof. Dr. Zhu‐Yin Wang Prof. Dr. Yong Qin Prof. Dr. Peng‐Fei Xu 《Angewandte Chemie (International ed. in English)》2018,57(18):5110-5114
Herein we describe a mild method for the dual C(sp3)?H bond functionalization of saturated nitrogen‐containing heterocycles through a sequential visible‐light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid derivatives, thus enabling the simultaneous functionalization of two vicinal C(sp3)?H bonds. 相似文献
17.
Dr. Xiaoming Wang Dr. Da‐Gang Yu Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2015,54(35):10280-10283
The first Cp*RhIII‐catalyzed arylation of unactivated C(sp3)? H bonds is presented. The unactivated primary C(sp3)? H bond of 2‐alkylpyridines can be activated by RhIII and further reacts with triarylboroxines to efficiently build new C(sp3)? aryl bonds. The methodology also provides a facile and efficient synthesis of unsymmetrical triarylmethanes by RhIII‐catalyzed C(sp3)? H arylation of diarylmethanes. 相似文献
18.
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
19.
Easily Accessible Auxiliary for Palladium‐Catalyzed Intramolecular Amination of C(sp2)H and C(sp3)H Bonds at δ‐ and ε‐Positions 下载免费PDF全文
Chao Wang Changpeng Chen Jingyu Zhang Jian Han Qian Wang Kun Guo Pei Liu Mingyu Guan Dr. Yingming Yao Prof. Dr. Yingsheng Zhao 《Angewandte Chemie (International ed. in English)》2014,53(37):9884-9888
An easily synthesized and accessible N,O‐bidentate auxiliary has been developed for selective C? H activation under palladium catalysis. The novel auxiliary showed its first powerful application in C? H functionalization of remote positions. Both C(sp2)? H and C(sp3)? H bonds at δ‐ and ε‐positions were effectively activated, thus giving tetrahydroquinolines, benzomorpholines, pyrrolidines, and indolines in moderate to excellent yields by palladium‐catalyzed intramolecular C? H amination. 相似文献
20.
Jian He Heng Jiang Ryosuke Takise Ru‐Yi Zhu Gang Chen Hui‐Xiong Dai T. G. Murali Dhar Jun Shi Hao Zhang Peter T. W. Cheng Jin‐Quan Yu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(2):795-799
A quinoline‐based ligand effectively promotes the palladium‐catalyzed borylation of C(sp3) H bonds. Primary β‐C(sp3) H bonds in carboxylic acid derivatives as well as secondary C(sp3) H bonds in a variety of carbocyclic rings, including cyclopropanes, cyclobutanes, cyclopentanes, cyclohexanes, and cycloheptanes, can thus be borylated. This directed borylation method complements existing iridium(I)‐ and rhodium(I)‐catalyzed C H borylation reactions in terms of scope and operational conditions. 相似文献