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1.
Stereoselective Synthesis of Highly Substituted Tetrahydrofurans through Diverted Carbene OH Insertion Reaction
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Simon M. Nicolle Dr. William Lewis Prof. Dr. Christopher J. Hayes Prof. Dr. Christopher J. Moody 《Angewandte Chemie (International ed. in English)》2015,54(29):8485-8489
Copper‐ or rhodium‐catalyzed reactions of diazocarbonyl compounds with β‐hydroxyketones give highly substituted tetrahydrofurans with excellent diastereoselectivity. Under mild conditions, the single‐step process starts as a carbene O? H insertion reaction, but is diverted by an intramolecular aldol reaction. 相似文献
2.
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
3.
Copper(I)‐Catalyzed Alkylation of Polyfluoroarenes through Direct CH Bond Functionalization
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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
4.
Copper‐Catalyzed NH Insertion and Oxidative Aromatization Cascade: Facile Synthesis of 2‐Arylaminophenols
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Dong Ding Xiaobing Lv Dr. Jian Li Guangyang Xu Dr. Bing Ma Prof. Dr. Jiangtao Sun 《化学:亚洲杂志》2014,9(6):1539-1542
A copper‐catalyzed cascade reaction of N‐H insertion and oxidative aromatization has been developed. 2‐Arylaminophenols have been prepared in moderate to high yields from the diazo substrates. Moreover, this newly established methodology allows efficient access to natural 1‐oxygenated carbazole alkaloids, such as glycozolicine and murrayafoline A. 相似文献
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6.
Synthesis of Di‐, Tri‐, and Tetrasubstituted Oxetanes by Rhodium‐Catalyzed OH Insertion and CC Bond‐Forming Cyclization
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Owen A. Davis Dr. James A. Bull 《Angewandte Chemie (International ed. in English)》2014,53(51):14230-14234
Oxetanes offer exciting potential as structural motifs and intermediates in drug discovery and materials science. Here an efficient strategy for the synthesis of oxetane rings incorporating pendant functional groups is described. A wide variety of oxetane 2,2‐dicarboxylates were accessed in high yields, including functionalized 3‐/4‐aryl‐ and alkyl‐substituted oxetanes and fused oxetane bicycles. Enantioenriched alcohols provided enantioenriched oxetanes with complete retention of configuration. The oxetane products were further derivatized, while the ring was maintained intact, thus highlighting their potential as building blocks for medicinal chemistry. 相似文献
7.
Intramolecular CH/OH Bond Cleavage with Water and Alcohol Using a Phosphine‐Free Ruthenium Carbene NCN Pincer Complex
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Demyan E. Prokopchuk Brian T. H. Tsui Dr. Alan J. Lough Prof. Dr. Robert H. Morris 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(51):16960-16968
Transition metal complexes that exhibit metal–ligand cooperative reactivity could be suitable candidates for applications in water splitting. Ideally, the ligands around the metal should not contain oxidizable donor atoms, such as phosphines. With this goal in mind, we report new phosphine‐free ruthenium NCN pincer complexes with a central N‐heterocyclic carbene donor and methylpyridyl N‐donors. Reaction with base generates a neutral, dearomatized alkoxo–amido complex, which has been structurally and spectroscopically characterized. The tert‐butoxide ligand facilitates regioselective, intramolecular proton transfer through a C?H/O?H bond cleavage process occurring at room temperature. Kinetic and thermodynamic data have been obtained by VT NMR experiments; DFT calculations support the observed behavior. Isolation and structural characterization of a doubly dearomatized phosphine complex also strongly supports our mechanistic proposal. The alkoxo–amido complex reacts with water to form a dearomatized ruthenium hydroxide complex, a first step towards phosphine‐free metal–ligand cooperative water splitting. 相似文献
8.
Catalytic Asymmetric Functionalization of Aromatic CH Bonds by Electrophilic Trapping of Metal‐Carbene‐Induced Zwitterionic Intermediates
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Shikun Jia Dr. Dong Xing Dan Zhang Prof. Dr. Wenhao Hu 《Angewandte Chemie (International ed. in English)》2014,53(48):13098-13101
Asymmetric functionalization of aromatic C? H bonds of N,N‐disubstituted anilines with diazo compounds and imines is reported for the efficient construction of α,α‐diaryl benzylic quaternary stereocenters in good yields with high diastereoselectivities and excellent enantioselectivities. This RhII/chiral phosphoric acid cocatalyzed transformation is proposed to proceed through a metal‐carbene‐induced zwitterionic intermediate which undergoes electrophilic trapping. To the best of our knowledge, this is the first asymmetric example of metal carbene‐induced intermolecular functionalization of aryl C? H bonds. 相似文献
9.
Rhodium(I)‐Catalyzed Sequential C(sp)C(sp3) and C(sp3)C(sp3) Bond Formation through Migratory Carbene Insertion
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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.
Yang Yang Prof. Dr. Stephen L. Buchwald 《Angewandte Chemie (International ed. in English)》2014,53(33):8677-8681
A copper‐based catalytic technique for the regioselective ortho C? H cyanation of vinylarenes has been developed. This method provides an effective means for the selective functionalization of vinylarene derivatives. A copper‐catalyzed cyanative dearomatization mechanism is proposed to account for the regiochemical course of this reaction. 相似文献
11.
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
12.
Enantioselective Palladium‐Catalyzed Insertion of α‐Aryl‐α‐diazoacetates into the OH Bonds of Phenols
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Xiu‐Lan Xie Prof. Shou‐Fei Zhu Jun‐Xia Guo Yan Cai Prof. Qi‐Lin Zhou 《Angewandte Chemie (International ed. in English)》2014,53(11):2978-2981
A palladium‐catalyzed asymmetric O? H insertion reaction was developed. Palladium complexes with chiral spiro bisoxazoline ligands promoted the insertion of α‐aryl‐α‐diazoacetates into the O? H bond of phenols with high yield and excellent enantioselectivity under mild reaction conditions. This palladium‐catalyzed asymmetric O? H insertion reaction provided an efficient and highly enantioselective method for the preparation of synthetically useful optically active α‐aryl‐α‐aryloxyacetates. 相似文献
13.
Ruthenium–Porphyrin‐Catalyzed Diastereoselective Intramolecular Alkyl Carbene Insertion into CH Bonds of Alkyl Diazomethanes Generated In Situ from N‐Tosylhydrazones
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Zhen Guo Jinhu Wei Prof. Dr. Chi‐Ming Che 《Angewandte Chemie (International ed. in English)》2014,53(51):14175-14180
With a ruthenium–porphyrin catalyst, alkyl diazomethanes generated in situ from N‐tosylhydrazones efficiently underwent intramolecular C(sp3)? H insertion of an alkyl carbene to give substituted tetrahydrofurans and pyrrolidines in up to 99 % yield and with up to 99:1 cis selectivity. The reaction displays good tolerance of many functionalities, and the procedure is simple without the need for slow addition with a syringe pump. From a synthetic point of view, the C? H insertion of N‐tosylhydrazones can be viewed as reductive coupling between a C?O bond and a C? H bond to form a new C? C bond, since N‐tosylhydrazones can be readily prepared from carbonyl compounds. This reaction was successfully applied in a concise synthesis of (±)‐pseudoheliotridane. 相似文献
14.
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
15.
[CpRu]‐Catalyzed Carbene Insertions into Epoxides: 1,4‐Dioxene Synthesis through SN1‐Like Chemistry with Retention of Configuration
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Dr. Thierry Achard Cecilia Tortoreto Dr. Amalia I. Poblador‐Bahamonde Dr. Laure Guénée Prof. Thomas Bürgi Prof. Jérôme Lacour 《Angewandte Chemie (International ed. in English)》2014,53(24):6140-6144
Rather than lead to the usual deoxygenation pathway, metal carbenes derived from α‐diazo‐β‐ketoesters undergo three‐atom insertions into epoxides using a combination of 1,10‐phenanthroline and [CpRu(CH3CN)3][BArF] as the catalyst. Original 1,4‐dioxene motifs are obtained as single regio‐ and stereoisomers. A perfect syn stereochemistry (retention, e.r. up to 97:3) is observed for the ring opening, which behaves as an SN1‐like transformation. 相似文献
16.
Hai‐Xu Wang Yann Richard Qingyun Wan Cong‐Ying Zhou Chi‐Ming Che 《Angewandte Chemie (International ed. in English)》2020,59(5):1845-1850
Described herein is an IrIII/porphyrin‐catalyzed intermolecular C(sp3)?H insertion reaction of a quinoid carbene (QC). The reaction was designed by harnessing the hydrogen‐atom transfer (HAT) reactivity of a metal‐QC species with aliphatic substrates followed by a radical rebound process to afford C?H arylation products. This methodology is efficient for the arylation of activated hydrocarbons such as 1,4‐cyclohexadienes (down to 40 min reaction time, up to 99 % yield, up to 1.0 g scale). It features unique regioselectivity, which is mainly governed by steric effects, as the insertion into primary C?H bonds is favored over secondary and/or tertiary C?H bonds in the substituted cyclohexene substrates. Mechanistic studies revealed a radical mechanism for the reaction. 相似文献
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18.
Copper‐Catalyzed Trifluoromethylation of Internal Olefinic CH Bonds: Efficient Routes to Trifluoromethylated Tetrasubstituted Olefins and N‐Heterocycles
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Zhifeng Mao Fei Huang Dr. Haifeng Yu Prof. Dr. Jiping Chen Prof. Dr. Zhengkun Yu Prof. Dr. Zhaoqing Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3439-3445
The functionalization of internal olefins has been a challenging task in organic synthesis. Efficient CuII‐catalyzed trifluoromethylation of internal olefins, that is, α‐oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push–pull effect from the polarized olefin substrates facilitates the internal olefinic C?H trifluoromethylation. Cyclic and acyclic dithioalkyl α‐oxoketene acetals were used as the substrates and various substituents were tolerated. The internal olefinic C?H bond cleavage was not involved in the rate‐determining step, and a mechanism that involves radicals is proposed based on a TEMPO‐quenching experiment of the trifluoromethylation reaction. Further derivatization of the resultant CF3 olefins led to multifunctionalized tetrasubstituted CF3 olefins and trifluoromethylated N‐heterocycles. 相似文献
19.
Stacey L. McDonald Charles E. Hendrick Prof. Dr. Qiu Wang 《Angewandte Chemie (International ed. in English)》2014,53(18):4667-4670
Direct amination of heteroarenes and arenes has been achieved in a one‐pot C? H zincation/copper‐catalyzed electrophilic amination procedure. This amination method provides an efficient and rapid approach to access a diverse range of heteroaromatic and aromatic amines including those previously inaccessible using C? H amination methods. The mild reaction conditions and good functional‐group compatibility demonstrate its great potential for the synthesis of important and complex amines. 相似文献
20.
Dr. Qing‐Qing Cheng Lynée A. Massey Brook S. Willett Dr. Yongming Deng Dr. Hadi Arman Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2018,57(32):10343-10346
Enoldiazoimides, a new subclass of enoldiazo compounds, generate enol‐substituted carbonyl ylides whose reactions with sulfur ylides enable an unprecedented formal [4+2] cycloaddition. The resulting multifunctionalized indolizidinones, which incorporate sulfur, are formed in good yields under mild reaction conditions. The uniqueness of this transformation stems from the role of the silyl‐protected enol, since the corresponding acetyldiazoimide failed to provide any cross‐products in metal‐catalyzed reactions with sulfur ylides. This copper‐catalyzed cycloaddition is initiated with the generation of enol‐substituted carbonyl ylides and sulfur ylides from enoldiazoimides and sulfonium salts, respectively, and proceeds through stepwise six‐membered ring formation, C?O and C?S bond cleavage, and silyl and acetyl group migration. 相似文献