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1.
Palladium‐Catalyzed/Norbornene‐Mediated CH Activation/ N‐Tosylhydrazone Insertion Reaction: A Route to Highly Functionalized Vinylarenes
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Dr. Ping‐Xin Zhou Lan Zheng Jun‐Wei Ma Yu‐Ying Ye Xue‐Yuan Liu Prof. Dr. Peng‐Fei Xu Prof. Dr. Yong‐Min Liang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(22):6745-6751
A straightforward method for the synthesis of highly functionalized vinylarenes through palladium‐catalyzed, norbornene‐mediated C?H activation/carbene migratory insertion is described. Extension to a one‐pot procedure is also developed. Furthermore, this method can also be used to generate polysubstituted bicyclic molecules. The reaction proceeds under mild conditions to give the products in satisfactory yields using readily available starting materials. This is a Catellani–Lautens reaction that incorporates different types of coupling partners. Additionally, this reaction is the first to demonstrate the possibility of combining Pd‐catalyzed insertion of diazo compounds and Pd‐catalyzed C?H activation. 相似文献
2.
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
3.
Catalyst‐Dependent Chemoselective Formal Insertion of Diazo Compounds into C−C or C−H Bonds of 1,3‐Dicarbonyl Compounds
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Zhaohong Liu Dr. Paramasivam Sivaguru Prof. Giuseppe Zanoni Prof. Edward A. Anderson Prof. Xihe Bi 《Angewandte Chemie (International ed. in English)》2018,57(29):8927-8931
A catalyst‐dependent chemoselective one‐carbon insertion of diazo compounds into the C?C or C?H bonds of 1,3‐dicarbonyl species is reported. In the presence of silver(I) triflate, diazo insertion into the C(=O)?C bond of the 1,3‐dicarbonyl substrate leads to a 1,4‐dicarbonyl product containing an all‐carbon α‐quaternary center. This reaction constitutes the first example of an insertion of diazo‐derived carbenoids into acyclic C?C bonds. When instead scandium(III) triflate was applied as the catalyst, the reaction pathway switched to formal C?H insertion, affording 2‐alkylated 1,3‐dicarbonyl products. Different reaction pathways are proposed to account for this powerful catalyst‐dependent chemoselectivity. 相似文献
4.
《Mendeleev Communications》2022,32(4):482-484
Rhodium(III) complexes catalyze the insertion of carbenoids generated from diazo compounds into E?H bonds (E = B, Si, N, but not C), although less efficiently than classical rhodium(II) carboxylates, despite formally higher oxidation state of the metal. 相似文献
5.
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
6.
Elevated Catalytic Activity of Ruthenium(II)–Porphyrin‐Catalyzed Carbene/Nitrene Transfer and Insertion Reactions with N‐Heterocyclic Carbene Ligands
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Ka‐Ho Chan Dr. Xiangguo Guan Dr. Vanessa Kar‐Yan Lo Prof. Dr. Chi‐Ming Che 《Angewandte Chemie (International ed. in English)》2014,53(11):2982-2987
Bis(NHC)ruthenium(II)–porphyrin complexes were designed, synthesized, and characterized. Owing to the strong donor strength of axial NHC ligands in stabilizing the trans M?CRR′/M?NR moiety, these complexes showed unprecedently high catalytic activity towards alkene cyclopropanation, carbene C? H, N? H, S? H, and O? H insertion, alkene aziridination, and nitrene C? H insertion with turnover frequencies up to 1950 min?1. The use of chiral [Ru(D4‐Por)(BIMe)2] ( 1 g ) as a catalyst led to highly enantioselective carbene/nitrene transfer and insertion reactions with up to 98 % ee. Carbene modification of the N terminus of peptides at 37 °C was possible. DFT calculations revealed that the trans axial NHC ligand facilitates the decomposition of diazo compounds by stabilizing the metal–carbene reaction intermediate. 相似文献
7.
Alexander J. Boddy Dominic P. Affron Christopher J. Cordier Emma L. Rivers Alan C. Spivey James A. Bull 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1472-1476
Methods that provide rapid access to new heterocyclic structures in biologically relevant chemical space provide important opportunities in drug discovery. Here, a strategy is described for the preparation of 2,2‐disubstituted azetidines, pyrrolidines, piperidines, and azepanes bearing ester and diverse aryl substituents. A one‐pot rhodium catalyzed N–H insertion and cyclization sequence uses diazo compounds to stitch together linear 1,m‐haloamines (m=2–5) to rapidly assemble 4 ‐, 5 ‐, 6 ‐, and 7 ‐membered saturated nitrogen heterocycles in excellent yields. Over fifty examples are demonstrated, including examples with diazo compounds derived from biologically active compounds. The products can be functionalized to afford α,α‐disubstituted amino acids and applied to fragment synthesis. 相似文献
8.
Shikun Jia Dong Xing Dan Zhang Wenhao Hu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(48):13314-13317
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.
Díaz-Requejo MM Belderrain TR Nicasio MC Pérez PJ 《Dalton transactions (Cambridge, England : 2003)》2006,(47):5559-5566
This contribution intends to highlight the use of the metal-catalyzed functionalization of unreactive carbon-hydrogen bonds by the carbene insertion methodology, that employs diazo compounds as the carbene source. 相似文献
10.
Yaseen Hussain Dr. Claire Empel Prof. Dr. Rene M. Koenigs Prof. Dr. Pankaj Chauhan 《Angewandte Chemie (International ed. in English)》2023,62(40):e202309184
The control of the reactivity of diazo compounds is commonly achieved by the choice of a suitable catalyst, e.g. via stabilization of singlet carbenes or radical intermediates. Herein, we report on the light-promoted reactivity of cyclic diazo imides with thiols, where the choice of solvent results in two fundamentally different reaction pathways. In dichloromethane (DCM), a carbene is formed initially and engages in a cascade C−H functionalization/thiolation reaction to deliver indane-fused pyrrolidines in good to excellent yields. When switching to acetonitrile solvent, the carbene pathway is shut down and an unusual reduction of the diazo compound occurs under otherwise identical reaction conditions, where the aryl thiol acts as reductant. A combined set of experimental and computational studies was carried out to obtain mechanistic understanding and to support that indane formation proceeds via the insertion of a triplet carbene, while the reduction of diazo imides proceeds via an electron transfer process. 相似文献
11.
Rhodium‐Catalyzed Regioselective N2‐Alkylation of Benzotriazoles with Diazo Compounds/Enynones via a Nonclassical Pathway
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Kai Wang Ping Chen Danqing Ji Prof. Dr. Xinhao Zhang Guangyang Xu Prof. Dr. Jiangtao Sun 《Angewandte Chemie (International ed. in English)》2018,57(38):12489-12493
A novel rhodium‐catalyzed highly selective N2‐alkylation of benzotriazoles with diazo compounds/enynones is achieved, providing N2‐alkylated benzotriazoles in good to excellent yields and with excellent N2 selectivities. Importantly, different to traditional carbene insertion into X?H (X=N, O etc) bonds, DFT calculations disclose that this selective N2‐alkylation probably proceeds through a formal 1,3‐ rather than 1,2‐H shift to give the final products. 相似文献
12.
Gold‐Catalyzed Formal C−C Bond Insertion Reaction of 2‐Aryl‐2‐diazoesters with 1,3‐Diketones
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《化学:亚洲杂志》2018,13(18):2606-2610
The transition‐metal‐catalyzed formal C−C bond insertion reaction of diazo compounds with monocarbonyl compounds is well established, but the related reaction of 1,3‐diketones instead gives C−H bond insertion products. Herein, we report a protocol for a gold‐catalyzed formal C−C bond insertion reaction of 2‐aryl‐2‐diazoesters with 1,3‐diketones, which provides efficient access to polycarbonyl compounds with an all‐carbon quaternary center. The aryl ester moiety plays a crucial role in the unusual chemoselectivity, and the addition of a Brønsted acid to the reaction mixture improves the yield of the C−C bond insertion product. A reaction mechanism involving cyclopropanation of a gold carbenoid with an enolate and ring‐opening of the resulting donor–acceptor‐type cyclopropane intermediate is proposed. This mechanism differs from that of the traditional Lewis‐acid‐catalyzed C−C bond insertion reaction of diazo compounds with monocarbonyl compounds, which involves a rearrangement of a zwitterion intermediate as a key step. 相似文献
13.
This paper describes the synthesis and reactivity of a novel class of quinone boronic esters. These compounds are prepared utilizing a highly regioselective D?tz annulation of Fischer carbene complexes with alkynylboronates. All substrates studied to date provided a single regioisomeric arylboronic ester product; the origin of this selectivity is discussed in the context of steric and electronic effects. Additionally, these compounds have been found to undergo Pd-catalyzed coupling reactions with a range of aryl and allyl halides and provides a strategy for the selective and predictable preparation of highly substituted quinones and hydroquinones. Finally, the propensity of this technique to prepare highly functionalized aromatic compounds in an expeditious fashion is demonstrated in the total synthesis of dimeric carbazole (+/-)-bis-N-dimethylbismurrayaquinone-A 33. 相似文献
14.
Amy N. Price Dr. Michael J. Cowley 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(18):6248-6252
We report the preparation of N‐heterocyclic carbene (NHC)‐stabilized compounds containing P=B double bonds. The reaction of the highly functionalized phosphinoborane Mes*(SiMe3)P?B(Cl)Cp* with Lewis bases allows access to base‐stabilized phosphinidene boranes Mes*P=B(L)Cp* (L=4‐dimethylaminopyridine (DMAP), NHC) by Me3SiCl elimination. The formation of these species is shown to proceed through transient borylphosphide anions generated by Me3Si abstraction. 相似文献
15.
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
16.
《中国化学》2018,36(10):945-949
The palladium(0)‐catalyzed nitrogen insertion into cyclic Si—Si bonds has been realized by using N‐tosylhydrazones/diazo compounds as the nitrogen source. The palladium(II) nitrene formation and subsequent migratory insertion process are proposed as the key steps for this reaction. 相似文献
17.
Ana Pereira Dr. Yohan Champouret Dr. Carmen Martín Dr. Eleuterio Álvarez Prof. Dr. Michel Etienne Prof. Dr. Tomás R. Belderraín Prof. Dr. Pedro J. Pérez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9769-9775
Copper–carbene [TpxCu?C(Ph)(CO2Et)] and copper–diazo adducts [TpxCu{η1‐N2C(Ph)(CO2Et)}] have been detected and characterized in the context of the catalytic functionalization of O?H bonds through carbene insertion by using N2?C(Ph)(CO2Et) as the carbene source. These are the first examples of these type of complexes in which the copper center bears a tridentate ligand and displays a tetrahedral geometry. The relevance of these complexes in the catalytic cycle has been assessed by NMR spectroscopy, and kinetic studies have demonstrated that the N‐bound diazo adduct is a dormant species and is not en route to the formation of the copper–carbene intermediate. 相似文献
18.
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
19.
An Immobilized‐Dirhodium Hollow‐Fiber Flow Reactor for Scalable and Sustainable C−H Functionalization in Continuous Flow
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Chun‐Jae Yoo Dr. Daniel Rackl Wenbin Liu Caroline B. Hoyt Brian Pimentel Prof. Ryan P. Lively Prof. Huw M. L. Davies Prof. Christopher W. Jones 《Angewandte Chemie (International ed. in English)》2018,57(34):10923-10927
A scalable flow reactor is demonstrated for enantioselective and regioselective rhodium carbene reactions (cyclopropanation and C?H functionalization) by developing cascade reaction methods employing a microfluidic flow reactor system containing immobilized dirhodium catalysts in conjunction with the flow synthesis of diazo compounds. This allows the utilization of the energetic diazo compounds in a safe manner and the recycling of the dirhodium catalysts multiple times. This approach is amenable to application in a bulk‐scale synthesis employing asymmetric C?H functionalization by stacking multiple fibers in one reactor module. The products from this sequential flow–flow reactor are compared with a conventional batch reactor or flow–batch reactor in terms of yield, regioselectivity, and enantioselectivity. 相似文献
20.
Synthesis of Bifunctional Allylic Compounds by Using Cyclopropenes as Functionalized Allyl Equivalents
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Sergio Mata Dr. Luis A. López Dr. Rubén Vicente 《Angewandte Chemie (International ed. in English)》2018,57(35):11422-11426
The synthesis of uncommon bifunctional allylic derivatives bearing a silane and an alcohol within the same allylic framework is reported. This method relies on the coupling of hydrosilanes with substituted and functionalized cyclopropenes, which deliver the allyl fragment. Rhodium(II) catalysts provide regioselective access to vinyl carbene intermediates, which easily undergo Si?H bond insertions. The transformation occurs with complete atom economy and shows a remarkably broad scope, including a intramolecular version for the synthesis of cyclic O?Si‐linked compounds as well as the synthesis of the corresponding allyl amines. 相似文献