1
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Tsurugi H, Akiyama T, Frye CW, Kakiuchi Y, Mashima K, Tonks IA. Evaluation of Tungsten Catalysis among Early Transition Metals for N-Aryl-2,3,4,5-tetraarylpyrrole Synthesis: Modular Access to N-Doped π-Conjugated Material Precursors. Inorg Chem 2024; 63:3037-3046. [PMID: 38300807 PMCID: PMC11059426 DOI: 10.1021/acs.inorgchem.3c03858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Low-valent tungsten species generated from WCl6 and N,N'-bis(trimethylsilyl)-2,5-dimethyldihydropyrazine (Si-Me2-DHP) promotes the catalytic formation of N-phenyl-2,3,4,5-tetraarylpyrroles 3aa-ka from diarylacetylenes 1a-k and azobenzene (2a). An initial catalyst activation process is a three-electron reduction of WCl6 with Si-Me2-DHP to afford transient 'WCl3' species. Catalytically active bis(imido)tungsten(VI) species via successive one-electron reduction and N═N bond cleavage of 2a was revealed by isolating W(═NPh)2Cl2(PMe2Ph)2 from imidotungsten(V) trichloride and 2a in the presence of PMe2Ph. The superior catalytic activity of the tungsten catalyst was clarified by a density functional theory study: activation energies for the key three steps, [2 + 2]-cycloaddition of W═NPh and diarylacetylene to form (iminoalkylidene)tungsten species, enyne metathesis with second diarylacetylene, and C-N bond formation, are reasonable values for the catalytic reaction at 180 °C. In addition, this tungsten catalyst overcame two distinct deactivation processes: α-enediamido formation and aggregation of the low-valent species, both of which were observed for previously developed vanadium and titanium catalysts. We also demonstrated the synthetic utility of pentaarylpyrroles 3aa and 3ba as well as N-(2-bromophenyl)-2,3,4,5-tetraarylpyrrole 3ab by derivatizing their π-conjugated compounds 9aa, 10ba, and 11ab.
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Affiliation(s)
- Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Takuya Akiyama
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Connor W. Frye
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Yuya Kakiuchi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Kazushi Mashima
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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2
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Huh DN, Koby RF, Stuart ZE, Dunscomb RJ, Schley ND, Tonks IA. Reassessment of N 2 activation by low-valent Ti-amide complexes: a remarkable side-on bridged bis-N 2 adduct is actually an arene adduct. Chem Sci 2022; 13:13330-13337. [PMID: 36507167 PMCID: PMC9682900 DOI: 10.1039/d2sc04368h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/13/2022] [Indexed: 12/15/2022] Open
Abstract
The complex {(TMEDA)2Li}{[Ti(N(TMS)2)2]2(μ-η2:η2-N2)2} (5-Li) is the only transition metal N2 complex ever reported with two side-on N2 adducts. In this report, the similarity of 5-Li to a new inverse sandwich toluene adduct {(PhMe)K}{[Ti(N(TMS)2)2]2(μ-PhMe)} (6-K) necessitated a re-examination of the structure of 5-Li. Through a reassessment of the original disordered crystal data of 5-Li and new independent syntheses brought about through revisitation of the original reaction conditions, 5-Li has been re-assigned as an inverse sandwich toluene adduct, {(TMEDA)2Li}{[Ti(N(TMS)2)2]2(μ-PhMe)} (6-Li). The original crystal data could be fitted almost equally well to structural solutions as either 5-Li or 6-Li, and this study highlights the importance of a holistic examination of modeled data and the need for secondary/complementary analytical methods in paramagnetic inorganic syntheses, especially when presenting unique and unexpected results. In addition, further examination of reduction reactions of Ti[N(TMS)2]3 and [(TMS)2N]2TiCl(THF) in the presence of KC8 revealed rich solvent- and counterion-dependent chemistry, including several degrees of N2 activation (bridging nitride complexes, terminal bridging N2 complexes) as well as ligand C-H activation.
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Affiliation(s)
- Daniel N Huh
- Department of Chemistry, University of Minnesota - Twin Cities Minneapolis MN 55455 USA
| | - Ross F Koby
- Department of Chemistry, University of Minnesota - Twin Cities Minneapolis MN 55455 USA
| | - Zoe E Stuart
- Department of Chemistry, University of Minnesota - Twin Cities Minneapolis MN 55455 USA
| | - Rachel J Dunscomb
- Department of Chemistry, University of Minnesota - Twin Cities Minneapolis MN 55455 USA
| | - Nathan D Schley
- Department of Chemistry, Vanderbilt University Nashville TN 37235 USA
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota - Twin Cities Minneapolis MN 55455 USA
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3
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Zhang Q, Gao R, Li Z, Zhou B, Tang A, Wang J, Zou JJ, Yang H. Manipulating the Conversion Kinetics of Polysulfides by Engineering Oxygen p-Band of Halloysite for Improved Li-S Batteries. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105661. [PMID: 34854559 DOI: 10.1002/smll.202105661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Polar oxides are widely used as the cathodes to impede the shuttle effect in lithium-sulfur batteries, but suffer from the sluggish desorption and conversion of polysulfides due to too strong affinity of polysulfides on oxygen sites. Herein, employing halloysite as a model, an approach to overcome these shortcomings is proposed via engineering oxygen p-band center by loading titanium dioxide nanoparticles onto Si-O surface of halloysite. Using density functional theory calculations, it is predicted that electron transfer from titanium dioxide nanoparticles to interfacial O sites results in downshift of p-band center of O sites that promote desorption of polysulfides and the cleavage of Li-S and S-S, accelerating the conversion kinetics of polysulfides. The designed composite cathode material delivers outstanding electrochemical performance in Li-S batteries, outperforming the recently reported similar cathodes. The concept could provide valuable insight into the design of other catalysts for Li-S batteries and beyond.
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Affiliation(s)
- Qiang Zhang
- Hunan Key Lab of Mineral Materials and Application, School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Ruijie Gao
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Zixiong Li
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Binghui Zhou
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
| | - Aidong Tang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China
| | - Jian Wang
- Department of Chemistry, Seoul National University, Seoul, 151-742, South Korea
| | - Ji-Jun Zou
- Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Huaming Yang
- Hunan Key Lab of Mineral Materials and Application, School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, China University of Geosciences, Wuhan, 430074, China
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China
- Hunan International Joint Lab of Mineral Materials, Central South University, Changsha, 410083, China
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4
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Evidence of cluster formation of pyrrole with mixed silver metal clusters, Agx-My (x = 4,5, y = 2/1 and M = Au/Ni/Cu) using DFT/SERS analysis. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2021.113569] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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5
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Fortier S, Gomez-Torres A. Redox chemistry of discrete low-valent titanium complexes and low-valent titanium synthons. Chem Commun (Camb) 2021; 57:10292-10316. [PMID: 34533140 DOI: 10.1039/d1cc02772g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Titanium is a versatile metal that has important applications in practical synthesis, though this is typically limited to stoichiometric reactions or Lewis acid catalysis. Recently, interest has grown in using titanium and other early-metals for redox catalysis; however, notable limitations exist due to the thermodynamic preference of these metals to adopt high oxidation states. Nonetheless, discrete low-valent titanium (LVT) complexes and their synthons (titanium complexes which chemically behave as LVT sources) are known. Here, we detail the various ligand platforms that are capable of stabilizing LVT compounds and present the redox chemistry of these systems. This includes a discussion of recent developments in the use of LVT synthons for accessing fully reversible oxidative-addition/reductive-elimination reactions.
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Affiliation(s)
- Skye Fortier
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
| | - Alejandra Gomez-Torres
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
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6
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Sueyoshi S, Taniguchi T, Tanaka S, Asakawa H, Nishimura T, Maeda K. Understanding the Polymerization of Diphenylacetylenes with Tantalum(V) Chloride and Cocatalysts: Production of Cyclic Poly(diphenylacetylene)s by Low-Valent Tantalum Species Generated in Situ. J Am Chem Soc 2021; 143:16136-16146. [PMID: 34499837 DOI: 10.1021/jacs.1c06811] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A systematic investigation of the polymerization of representative diphenylacetylenes with TaCl5 and cocatalysts suggested that low-valent Ta species, which are formed by in situ reduction of TaCl5 by the cocatalysts, are involved in the polymerization and that the polymerization reaction proceeds by an insertion ring expansion mechanism via the formation of tantalacyclopentadiene intermediates, rather than the previously considered metathesis mechanism. This polymerization mechanism indicates the production of unprecedented cis-stereoregular cyclic poly(diphenylacetylene)s. Indeed, the possibilities of a cyclic structure and high cis-stereoregularity of the resulting polymers were reasonably supported by the results of their detailed atomic force microscopy (AFM) and NMR analyses, respectively.
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Affiliation(s)
- Shingyo Sueyoshi
- Graduate School of Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Tsuyoshi Taniguchi
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Saki Tanaka
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Hitoshi Asakawa
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.,Nanomaterials Research Institute (NanoMaRi), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.,Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Tatsuya Nishimura
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Katsuhiro Maeda
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.,Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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7
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Abstract
Titanium is an attractive metal for catalytic reaction development: it is earth-abundant, inexpensive, and generally nontoxic. However-like most early transition metals-catalytic redox reactions with Ti are difficult because of the stability of the high-valent TiIV state. Understanding the fundamental mechanisms behind Ti redox processes is key for making progress toward potential catalytic applications. This Account details recent progress in Ti-catalyzed (and -mediated) oxidative amination reactions that proceed through formally TiII/TiIV catalytic cycles.This class of reactions is built on our initial discovery of Ti-catalyzed [2 + 2 + 1] pyrrole synthesis from alkynes and azobenzene, where detailed mechanistic studies have revealed important factors that allow for catalytic turnover despite the inherent difficulty of Ti redox. Two important conclusions from mechanistic studies are that (1) low-valent Ti intermediates in catalysis can be stabilized through coordination of π-acceptor substrates or products, where they can act as "redox-noninnocent" ligands through metal-to-ligand π back-donation, and (2) reductive elimination processes with Ti proceed through π-type electrocyclic (or pericyclic) reaction mechanisms rather than direct σ-bond coupling.The key reactive species in Ti-catalyzed oxidative amination reactions are Ti imidos (Ti≡NR), which can be generated from either aryl diazenes (RN═NR) or organic azides (RN3). These Ti imidos can then undergo [2 + 2] cycloadditions with alkynes, resulting in intermediates that can be coupled to an array of other unsaturated functional groups, including alkynes, alkenes, nitriles, and nitrosos. This basic reactivity pattern has been extended into a broad range of catalytic and stoichiometric oxidative multicomponent coupling reactions of alkynes and other reactive small molecules, leading to multicomponent syntheses of various heterocycles and aminated building blocks.For example, catalytic oxidative coupling of Ti imidos with two different alkynes leads to pyrroles, while stoichiometric oxidative coupling with alkynes and nitriles leads to pyrazoles. These heterocycle syntheses often yield substitution patterns that are complementary to those of classical condensation routes and provide access to new electron-rich, highly substituted heteroaromatic scaffolds. Furthermore, catalytic oxidative alkyne carboamination reactions can be accomplished via reaction of Ti imidos with alkynes and alkenes, yielding α,β-unsaturated imine or cyclopropylimine building blocks. New catalytic and stoichiometric oxidative amination methods such as alkyne α-diimination, isocyanide imination, and ring-opening oxidative amination of strained alkenes are continuously emerging as a result of better mechanistic understanding of Ti redox catalysis.Ultimately, these Ti-catalyzed and -mediated oxidative amination methods demonstrate the importance of examining often-overlooked elements like the early transition metals through the lens of modern catalysis: rather than a lack of utility, these elements frequently have undiscovered potential for new transformations with orthogonal or complementary selectivity to their late transition metal counterparts.
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Affiliation(s)
- Ian A. Tonks
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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8
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Xiong M, Liang X, Zhou Y, Pan Y. Synthesis of Polysubstituted Pyrroles through Electro-Oxidative Annulation of 1,3-Dicarbonyl Compounds and Primary Amines. J Org Chem 2021; 86:4986-4993. [PMID: 33726491 DOI: 10.1021/acs.joc.0c02911] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reported herein is a synthetic method of polysubstituted pyrroles from easily available materials, 1,3-dicarbonyl compounds and primary amines, via electro-oxidative intermolecular annulation. Under similar conditions, enamines are also converted smoothly into desired products, indicating that in situ formed enamines are crucial intermediates for the first transformation. Neither transition-metal salts nor harsh conditions are required to facilitate the dehydrocyclization process.
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Affiliation(s)
- Mingteng Xiong
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Xiao Liang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yifeng Zhou
- College of Life Sciences, China Jiliang University, Hangzhou 310027, China
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
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9
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Beaumier EP, Ott AA, Wen X, Davis-Gilbert ZW, Wheeler TA, Topczewski JJ, Goodpaster JD, Tonks IA. Ti-catalyzed ring-opening oxidative amination of methylenecyclopropanes with diazenes. Chem Sci 2020; 11:7204-7209. [PMID: 34123005 PMCID: PMC8159277 DOI: 10.1039/d0sc01998d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/20/2020] [Indexed: 12/22/2022] Open
Abstract
The ring-opening oxidative amination of methylenecyclopropanes (MCPs) with diazenes catalyzed by py3TiCl2(NR) complexes is reported. This reaction selectively generates branched α-methylene imines as opposed to linear α,β-unsaturated imines, which are difficult to access via other methods. Products can be isolated as the imine or hydrolyzed to the corresponding ketone in good yields. Mechanistic investigation via density functional theory suggests that the regioselectivity of these products results from a Curtin-Hammett kinetic scenario, where reversible β-carbon elimination of a spirocyclic [2 + 2] azatitanacyclobutene intermediate is followed by selectivity-determining β-hydrogen elimination of the resulting metallacycle. Further functionalizations of these branched α-methylene imine products are explored, demonstrating their utility as building blocks.
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Affiliation(s)
- Evan P Beaumier
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Amy A Ott
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Xuelan Wen
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Zachary W Davis-Gilbert
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - T Alexander Wheeler
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Joseph J Topczewski
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Jason D Goodpaster
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota - Twin Cities 207 Pleasant St SE Minneapolis MN 55455 USA
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10
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Kawakita K, Kakiuchi Y, Tsurugi H, Mashima K, Parker BF, Arnold J, Tonks IA. Reactivity of terminal imido complexes of group 4-6 metals: stoichiometric and catalytic reactions involving cycloaddition with unsaturated organic molecules. Coord Chem Rev 2020; 407:213118. [PMID: 32863399 PMCID: PMC7453927 DOI: 10.1016/j.ccr.2019.213118] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Imido complexes of early transition metals are key intermediates in the synthesis of many nitrogen-containing organic compounds. The metal-nitrogen double bond of the imido moiety undergoes [2+2] cycloaddition reactions with various unsaturated organic molecules to form new nitrogen-carbon and nitrogen-heteroatom bonds. This review article focuses on reactivity of the terminal imido complexes of Group 4-6 metals, summarizing their stoichiometric reactions and catalytic applications for a variety of reactions including alkyne hydroamination, alkyne carboamination, pyrrole formation, imine metathesis, and condensation reactions of carbonyl compounds with isocyanates.
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Affiliation(s)
- Kento Kawakita
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Yuya Kakiuchi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Bernard F. Parker
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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11
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Gómez-Torres A, Aguilar-Calderón JR, Saucedo C, Jordan A, Metta-Magaña A, Pinter B, Fortier S. Reversible oxidative-addition and reductive-elimination of thiophene from a titanium complex and its thermally-induced hydrodesulphurization chemistry. Chem Commun (Camb) 2020; 56:1545-1548. [PMID: 31922152 DOI: 10.1039/c9cc09267f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The masked Ti(ii) synthon (Ketguan)(η6-ImDippN)Ti (1) oxidatively adds across thiophene to give ring-opened (Ketguan)(ImDippN)Ti[κ2-S(CH)3CH] (2). Complex 2 is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate 1 - a rare example of early-metal mediated oxidative-addition/reductive-elimination chemistry. DFT calculations indicate strong titanium π-backdonation to the thiophene π*-orbitals leads to the observed thiophene ring opening across titanium, while a proposed photoinduced LMCT promotes the reverse thiophene elimination from 2. Finally, pressurizing solutions of 2 with H2 (150 psi) at 80 °C leads to the hydrodesulphurization of thiophene to give the Ti(iv) sulphide (Ketguan)(ImDippN)Ti(S) (3) and butane.
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Affiliation(s)
- Alejandra Gómez-Torres
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
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12
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Tian M, Liu Y, Zhao W, Wang W, Wang L, Chen D, Zhao H, Meng F, Zhen Y, Qi T. Study on the grain size control of metatitanic acid in a mixture acid system based on Arrhenius and Boltzmann fitting. RSC Adv 2020; 10:1055-1065. [PMID: 35494473 PMCID: PMC9047982 DOI: 10.1039/c9ra08503c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/01/2019] [Indexed: 11/23/2022] Open
Abstract
Herein, to control the particle size of metatitanic acid produced via titanium thermal hydrolysis in sulfuric–chloric mixture acid (SCMA) solutions, the relationship between its grain size and hydrolysis parameters is discussed, and the corresponding mathematical model was established using the experimental data. Firstly, Ti(OH)(SO4)(Cl)(H2O)3 was selected as the most likely initial structure in the SCMA solution by comparing the experimental and corresponding simulated Raman spectra by density functional theory (DFT). Secondly, according to the predicted initial structure of TiO2+ and the experimental data for the hydrolysis process, with an increase in the concentration of TiO2+ and reaction temperature, the hydrolysis rate and grain size increased, while the agglomerate particle size decreased. Finally, a mathematic model was established and fitted by the Arrhenius equation and the Boltzmann distribution to describe the relationship between the grain size and hydrolysis parameters, as follows: Herein, to control the particle size of metatitanic acid produced via titanium thermal hydrolysis in sulfuric–chloric acid (SCMA) solutions, the relationship between its grain size and hydrolysis parameters are discussed, and the corresponding methematical model is discussed using the experimental data.![]()
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Affiliation(s)
- Ming Tian
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Yahui Liu
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Wei Zhao
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Weijing Wang
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Lina Wang
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Desheng Chen
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Hongxin Zhao
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Fancheng Meng
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Yulan Zhen
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
| | - Tao Qi
- National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering Beijing 100190 PR China .,University of Chinese Academy of Sciences Beijing 100190 PR China
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13
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Manßen M, Schafer LL. Titanium catalysis for the synthesis of fine chemicals – development and trends. Chem Soc Rev 2020; 49:6947-6994. [DOI: 10.1039/d0cs00229a] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Atlas as a Titan(ium) is holding the earth-abundant chemistry world. Titanium is the second most abundant transition metal, is a key player in important industrial processes (e.g. polyethylene) and shows much promise for diverse applications in the future.
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Affiliation(s)
- Manfred Manßen
- The Department of Chemistry
- The University of British Columbia
- Vancouver
- Canada
| | - Laurel L. Schafer
- The Department of Chemistry
- The University of British Columbia
- Vancouver
- Canada
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14
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Beaumier EP, McGreal ME, Pancoast AR, Wilson RH, Moore JT, Graziano BJ, Goodpaster JD, Tonks IA. Carbodiimide Synthesis via Ti-Catalyzed Nitrene Transfer from Diazenes to Isocyanides. ACS Catal 2019; 9:11753-11762. [PMID: 34113477 DOI: 10.1021/acscatal.9b04107] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Simple Ti imido halide complexes such as [Br2Ti(N t Bu)py2]2 are competent catalysts for the synthesis of unsymmetrical carbodiimides via Ti-catalyzed nitrene transfer from diazenes or azides to isocyanides. Both alkyl and aryl isocyanides are compatible with the reaction conditions, although product inhibition with sterically unencumbered substrates sometimes limits the yield when diazenes are employed as the oxidant. The reaction mechanism has been investigated both experimentally and computationally, wherein a key feature is that the product release is triggered by electron transfer from an η 2-carbodiimide to a Ti-bound azobenzene. This ligand-to-ligand redox buffering obviates the need for high-energy formally TiII intermediates and provides further evidence that substrate and product "redox noninnocence" can promote unusual Ti redox catalytic transformations.
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Affiliation(s)
- Evan P. Beaumier
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Meghan E. McGreal
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Adam R. Pancoast
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - R. Hunter Wilson
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - James T. Moore
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Brendan J. Graziano
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Jason D. Goodpaster
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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15
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Kawakita K, Beaumier EP, Kakiuchi Y, Tsurugi H, Tonks IA, Mashima K. Bis(imido)vanadium(V)-Catalyzed [2+2+1] Coupling of Alkynes and Azobenzenes Giving Multisubstituted Pyrroles. J Am Chem Soc 2019; 141:4194-4198. [PMID: 30731038 PMCID: PMC6460926 DOI: 10.1021/jacs.8b13390] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The combination of VCl3(THF)3 and N, N-bis(trimethylsilyl)aniline (1a) is an efficient catalyst for the [2+2+1] coupling reaction of alkynes and azobenzenes, giving multisubstituted pyrroles. A plausible reaction mechanism involves the generation of a mono(imido)vanadium(III) species as an initiation step, where 1a served as an imido source with concomitant release of 2 equiv of ClSiMe3, followed by a reaction with azobenzene to form a catalytically active bis(imido)vanadium(V) species via N═N bond cleavage.
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Affiliation(s)
- Kento Kawakita
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Evan P. Beaumier
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Yuya Kakiuchi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
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16
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Beaumier EP, Pearce AJ, See XY, Tonks IA. Modern applications of low-valent early transition metals in synthesis and catalysis. Nat Rev Chem 2018; 3:15-34. [PMID: 30989127 DOI: 10.1038/s41570-018-0059-x] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Low-valent early transition metals are often intrinsically highly reactive as a result of their strong propensity toward oxidation to more stable high-valent states. Harnessing these highly reducing complexes for productive reactivity is potentially powerful for C-C bond construction, organic reductions, small-molecule activation and many other reactions that offer orthogonal chemoselectivity and/or regioselectivity patterns to processes promoted by late transition metals. Recent years have seen many exciting new applications of low-valent metals through building new catalytic and/or multicomponent reaction manifolds out of classical reactivity patterns. In this Review, we survey new methods that employ early transition metals and invoke low-valent precursors or intermediates in order to identify common themes and strategies in synthesis and catalysis.
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Affiliation(s)
- Evan P Beaumier
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Adam J Pearce
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Xin Yi See
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Ian A Tonks
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
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17
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Group 4 Complexes Bearing Pyrrolide Ligand for Intramolecular Alkene Hydroamination and Activation of C≡N Bond. Z Anorg Allg Chem 2018. [DOI: 10.1002/zaac.201800109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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18
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Manßen M, de Graaff S, Meyer MF, Schmidtmann M, Beckhaus R. Direct Access to Titanocene Imides via Bis(η5:η1-penta-fulvene)titanium Complexes and Primary Amines. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00264] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Manfred Manßen
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Simon de Graaff
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - May-Franzis Meyer
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Marc Schmidtmann
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Rüdiger Beckhaus
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
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19
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Davis-Gilbert ZW, Wen X, Goodpaster JD, Tonks IA. Mechanism of Ti-Catalyzed Oxidative Nitrene Transfer in [2 + 2 + 1] Pyrrole Synthesis from Alkynes and Azobenzene. J Am Chem Soc 2018; 140:7267-7281. [PMID: 29763560 PMCID: PMC6508086 DOI: 10.1021/jacs.8b03546] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A combined computational and experimental study on the mechanism of Ti-catalyzed formal [2 + 2 + 1] pyrrole synthesis from alkynes and aryl diazenes is reported. This reaction proceeds through a formally TiII/TiIV redox catalytic cycle as determined by natural bond orbital (NBO) and intrinsic bond orbital (IBO) analysis. Kinetic analysis of the reaction of internal alkynes with azobenzene reveals a complex equilibrium involving Ti═NPh monomer/dimer equilibrium and Ti═NPh + alkyne [2 + 2] cycloaddition equilibrium along with azobenzene and pyridine inhibition equilibria prior to rate-determining second alkyne insertion. Computations support this kinetic analysis, provide insights into the structure of the active species in catalysis and the roles of solvent, and provide a new mechanism for regeneration of the Ti imido catalyst via disproportionation. Reductive elimination from a 6-membered azatitanacyclohexadiene species to generate pyrrole-bound TiII is surprisingly facile and occurs through a unique electrocyclic reductive elimination pathway similar to a Nazarov cyclization. The resulting TiII species are stabilized through backbonding into the π* of the pyrrole framework, although solvent effects also significantly stabilize free TiII species that are required for pyrrole loss and catalytic turnover. Further computational and kinetic analysis reveals that in complex reactions with unysmmetric alkynes the resulting pyrrole regioselectivity is driven primarily by steric effects for terminal alkynes and inductive effects for internal alkynes.
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Affiliation(s)
| | | | - Jason D. Goodpaster
- Department of Chemistry, University of Minnesota – Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota – Twin Cities, Minneapolis, Minnesota 55455, United States
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20
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Guo J, Lu Y, Zhao R, Liu Z, Menberu W, Wang ZX. Strong Preference of the Redox-Neutral Mechanism over the Redox Mechanism for the Ti IV Catalysis Involved in the Carboamination of Alkyne with Alkene and Diazene. Chemistry 2018; 24:7010-7025. [PMID: 29709085 DOI: 10.1002/chem.201800339] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/01/2018] [Indexed: 02/01/2023]
Abstract
Titanium catalysis generally prefers redox-neutral mechanisms. Yet it has been reported that titanium could promote bond formations in a way similar to reductive elimination. Accordingly, redox catalytic cycles involving TiIV /TiII cycling have been considered. By studying, as an example, the carboamination of alkynes with alkenes and azobenzene catalyzed by the [TiIV ]=NPh imido complex, we performed DFT computations to gain an understanding of how the "abnormal" catalysis takes place, thereby allowing us to clarify whether the catalysis really follows TiIV /TiII redox mechanisms. The reaction first forms an azatitanacyclohexene by alkyne addition to the [TiIV ]=NPh bond, followed by alkene insertion. The azatitanacyclohexene can either undergo Cα -Cγ coupling, to afford bicyclo[3.1.0]imine, or β-H elimination, to yield a [TiIV ]-H hydride, which then undergoes Cα =Cβ or Cγ =Cδ insertion to give an α,β- or β,γ-unsaturated imine, respectively. Both the geometric and electronic structures indicate that the catalytic cycles proceed through redox-neutral mechanisms. The alternative redox mechanisms (e.g., by N-H or C-H reductive elimination) are substantially less favorable. We concluded that electronically, the TiIV catalysis intrinsically favors the redox-neutral mechanism, because a redox pathway would involve TiII structures either in the triplet ground state or in the high-lying open-shell singlet state, but the involvement of triplet TiII structures is spin-forbidden and that of singlet TiII structures is energetically disadvantageous.
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Affiliation(s)
- Jiandong Guo
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Yu Lu
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruihua Zhao
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Zheyuan Liu
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Wasihun Menberu
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhi-Xiang Wang
- School of Chemical Sciences, University of the Chinese Academy of Sciences, Beijing, 100049, China
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21
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Yu SY, Ren P, Zheng HM, Zhang CG. Copolymerization Mechanisms of Propylene and Norbornadiene Catalyzed by Zirconocene Complexes: A Density Functional Theory Study. B KOREAN CHEM SOC 2018. [DOI: 10.1002/bkcs.11399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Shu-Yuan Yu
- Department of Chemistry and Material Science; Langfang Teachers University; Langfang 065000 China
| | - Ping Ren
- Department of Chemistry and Material Science; Langfang Teachers University; Langfang 065000 China
| | - Hui-Min Zheng
- Department of Chemistry and Material Science; Langfang Teachers University; Langfang 065000 China
| | - Cheng-Gen Zhang
- Department of Chemistry and Material Science; Langfang Teachers University; Langfang 065000 China
- College of Chemistry and Chemical Engineering; University of Chinese Academy of Sciences; Beijing 100049 China
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22
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Davis-Gilbert ZW, Tonks IA. Titanium redox catalysis: insights and applications of an earth-abundant base metal. Dalton Trans 2018; 46:11522-11528. [PMID: 28795719 DOI: 10.1039/c7dt02319g] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
π-Acid ancillary ligands, reactants, or products can stabilize reactive low valent Ti intermediates through backbonding, and present opportunities for the development of vast new classes of Ti-catalyzed redox reactions with practical applications.
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23
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Sun H, Xu S, Xing Z, Liu L, Feng S, Fang B, Xie X, She X. Rapid construction of complex tetracyclic frameworks via a gold(i)-catalyzed tandem 1,2-acyloxy migration/[3 + 2] cycloaddition/Friedel–Crafts type cyclization reaction of linear enynyl esters. Org Chem Front 2017. [DOI: 10.1039/c7qo00511c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magic “Au”: 3 rings and 2–3 quaternary centers were constructed in one step!
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Affiliation(s)
- Haiyu Sun
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Shiyan Xu
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Zhimin Xing
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Lin Liu
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Shangbiao Feng
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Bowen Fang
- Chemical Engineering Institute
- Northwest University for Nationalities
- Lanzhou
- People's Republic of China
| | - Xingang Xie
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
| | - Xuegong She
- State Key Laboratory of Applied Organic Chemistry
- Department of Chemistry
- Lanzhou University
- Lanzhou
- People's Republic of China
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