1
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Hosoya H, Akiyama T, Mashima K, Tsurugi H. Bis(neopentylglycolato)diboron (B 2nep 2) as a bidentate ligand and a reducing agent for early transition metal chlorides giving MCl 4(B 2nep 2) complexes. Dalton Trans 2023; 52:13154-13160. [PMID: 37655795 DOI: 10.1039/d3dt01828h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
We found that bis(neopentylglycolato)diboron (B2nep2) served as a bidentate ligand and a one-electron reducing agent for early transition metal chlorides to afford MCl4(B2nep2). Treatment of B2nep2 with MCl5 (M = Nb and Mo) produced MCl4(B2nep2) via two successive reactions, coordination of B2nep2 to the metal center and one-electron reduction from M(V) to M(IV), while coordination of B2nep2 to MCl4 (M = Zr, Ti) was observed without reduction of the central metals. DFT studies for the reduction of NbCl5 by B2nep2 clarified the initial formation of seven-coordinated and B2nep2-ligated Nb(V) species, NbCl5(B2nep2), and one chloride on niobium(V) moves to the Lewis acidic boron center to generate NbCl4[(B2nep2)Cl]. The chloride on the boron atom of NbCl4[(B2nep2)Cl] is trapped by the second B2nep2 to give [NbCl4(B2nep2)][ClB2nep2]. After the formation of [ClB2nep2]- as an anionic sp2-sp3 diboron adduct, one-electron reduction of the niobium(V) center produces NbCl4(B2nep2) along with [ClB2nep2]˙ as a plausible diboron species, whose decomposition affords ClBnep and B2nep2. The reduction of metal halides in the presence of B2nep2 was exemplified by green LED irradiation of TiCl4(B2nep2), producing chloride-bridged titanium(III) species, (B2nep2)TiCl2(μ-Cl)2TiCl2(B2nep2).
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Affiliation(s)
- Hiromu Hosoya
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
| | - Takuya Akiyama
- 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.
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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2
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Xu M, Wang Z, Sun Z, Ouyang Y, Ding Z, Yu T, Xu L, Li P. Diboron(4)-Catalyzed Remote [3+2] Cycloaddition of Cyclopropanes via Dearomative/Rearomative Radical Transmission through Pyridine. Angew Chem Int Ed Engl 2022; 61:e202214507. [PMID: 36344444 DOI: 10.1002/anie.202214507] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Indexed: 11/09/2022]
Abstract
Ring structures such as pyridine, cyclopentane or their combinations are important motifs in bioactive molecules. In contrast to previous cycloaddition reactions that necessitated a directly bonded initiating functional group, this work demonstrated a novel through-(hetero)arene radical transmission concept for selective activation of a remote bond. An efficient, metal-free and atom-economical [3+2] cycloaddition between 4-pyridinyl cyclopropanes and alkenes or alkynes has been developed for modular synthesis of pyridine-substituted cyclopentanes, cyclopentenes and bicyclo[2.1.1]hexanes that are difficult to access using known methods. This complexity-building reaction was catalyzed by a very simple and inexpensive diboron(4) compound and took place via dearomative/rearomative processes. The substrate scope was broad and more than 100 new compounds were prepared in generally high yields. Mechanistic experiments and density function theory (DFT) investigation supported a radical relay catalytic cycle involving alkylidene dihydropyridine radical intermediates and boronyl radical transfer.
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Affiliation(s)
- Ming Xu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, China
| | - Zhijun Wang
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi, Xinjiang, 832003, China
| | - Zhaohui Sun
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, China
| | - Yizhao Ouyang
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, China
| | - Zhengwei Ding
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
| | - Tao Yu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, China
| | - Liang Xu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi, Xinjiang, 832003, China
| | - Pengfei Li
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
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3
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Piers W, Clapson M, Dubrawski Z, Gelfand B. Facile Deoxygenative Reduction of a Bridging Carbonato Ligand with Silyl and Boryl 4,4’‐Bipyridinylidene Reagents. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Warren Piers
- University of Calgary Department of Chemistry 2500 University Dr. NW T2N 1N4 Calgary CANADA
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4
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Raut RK, Waghamare AB, Patel N, Majumdar M. Role of N, N′‐diboryl‐4, 4′‐bipyridinylidene in the Transition metal‐free Borylation of Aryl Halides and Direct C‐H arylation of Unactivated Benzene. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ravindra K. Raut
- Indian Institute of Science Education and Research Pune Chemistry INDIA
| | | | - Niranjan Patel
- Indian Institute of Science Education and Research Pune Chemistry INDIA
| | - Moumita Majumdar
- Indian Institute of Science Education and Research, Pune Chemistry Dr. Homi Bhabha RoadPashan 411008 Pune INDIA
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5
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Jeong E, Heo J, Jin S, Kim D, Chang S. KO tBu-Catalyzed 1,2-Silaboration of N-Heteroarenes to Access 2-Silylheterocycles: A Cooperative Model for the Regioselectivity. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Eunchan Jeong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalization, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Joon Heo
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalization, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Seongho Jin
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalization, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Dongwook Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalization, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Sukbok Chang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Catalytic Hydrocarbon Functionalization, Institute for Basic Science (IBS), Daejeon 34141, Korea
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6
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Jang M, Lim T, Park BY, Han MS. Metal-Free, Rapid, and Highly Chemoselective Reduction of Aromatic Nitro Compounds at Room Temperature. J Org Chem 2022; 87:910-919. [PMID: 34983185 DOI: 10.1021/acs.joc.1c01431] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this study, we developed a metal-free and highly chemoselective method for the reduction of aromatic nitro compounds. This reduction was performed using tetrahydroxydiboron [B2(OH)4] as the reductant and 4,4'-bipyridine as the organocatalyst and could be completed within 5 min at room temperature. Under optimal conditions, nitroarenes with sensitive functional groups, such as vinyl, ethynyl, carbonyl, and halogen, were converted into the corresponding anilines with excellent selectivity while avoiding the undesirable reduction of the sensitive functional groups.
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Affiliation(s)
- Mingyeong Jang
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Taeho Lim
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Byoung Yong Park
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Min Su Han
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
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7
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Beagan DM, Cabelof AC. Recent advances in metal-mediated nitrogen oxyanion reduction using reductively borylated and silylated N-heterocycles. Dalton Trans 2022; 51:2203-2213. [PMID: 35044399 DOI: 10.1039/d1dt03740d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reduction of nitrogen oxyanions is critical for the remediation of eutrophication caused by anthropogenic perturbations to the natural nitrogen cycle. There are many approaches to nitrogen oxyanion reduction, and here we report our advances in reductive deoxygenation using pre-reduced N-heterocycles. We show examples of nitrogen oxyanion reduction using Cr, Fe, Co, Ni, and Zn, and we evaluate the role of metal choice, number of coordinated oxyanions, and ancillary ligands on the reductive transformations. We report the experimental challenges faced and provide an outlook on new directions to repurpose nitrogen oxyanions into value-added products.
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Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Alyssa C Cabelof
- Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana, USA
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8
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Kuehn L, Zapf L, Werner L, Stang M, Würtemberger-Pietsch S, Krummenacher I, Braunschweig H, Lacôte E, Marder TB, Radius U. NHC induced radical formation via homolytic cleavage of B–B bonds and its role in organic reactions. Chem Sci 2022; 13:8321-8333. [PMID: 35919710 PMCID: PMC9297536 DOI: 10.1039/d2sc02096c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/07/2022] [Indexed: 11/21/2022] Open
Abstract
New borylation methodologies have been reported recently, wherein diboron(4) compounds apparently participate in free radical couplings via the homolytic cleavage of the B–B bond. We report herein that bis-NHC adducts of the type (NHC)2·B2(OR)4, which are thermally unstable and undergo intramolecular ring expansion reactions (RER), are sources of boryl radicals of the type NHC–BR2˙, exemplified by Me2ImMe·Bneop˙ 1a (Me2ImMe = 1,3,4,5-tetramethyl-imidazolin-2-ylidene, neop = neopentylglycolato), which are formed by homolytic B–B bond cleavage. Attempts to apply the boryl moiety 1a in a metal-free borylation reaction by suppressing the RER failed. However, based on these findings, a protocol was developed using Me2ImMe·B2pin23 for the transition metal- and additive-free boryl transfer to substituted aryl iodides and bromides giving aryl boronate esters in good yields. Analysis of the side products and further studies concerning the reaction mechanism revealed that radicals are likely involved. An aryl radical was trapped by TEMPO, an EPR resonance, which was suggestive of a boron-based radical, was detected in situ, and running the reaction in styrene led to the formation of polystyrene. The isolation of a boronium cation side product, [(Me2ImMe)2·Bpin]+I−7, demonstrated the fate of the second boryl moiety of B2pin2. Interestingly, Me2ImMe NHC reacts with aryl iodides and bromides generating radicals. A mechanism for the boryl radical transfer from Me2ImMe·B2pin23 to aryl iodides and bromides is proposed based on these experimental observations. Bis-NHC adducts of the type (NHC)2·B2(OR)4 are sources of boryl radicals of the type NHC–BR2˙, which are formed by homolytic B–B bond cleavage.![]()
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Affiliation(s)
- Laura Kuehn
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ludwig Zapf
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Luis Werner
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Stang
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Sabrina Würtemberger-Pietsch
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Emmanuel Lacôte
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, CNES, ArianeGroup, LHCEP, Bât. Raulin, 2 rue Victor Grignard, F-69622 Villeurbanne, France
| | - Todd B. Marder
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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9
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Khalimon AY. Deoxygenative hydroboration of carboxamides: a versatile and selective synthetic approach to amines. Dalton Trans 2021; 50:17455-17466. [PMID: 34787155 DOI: 10.1039/d1dt03516a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deoxygenative reduction of amides is considered as an attractive method for preparation of synthetically valuable amines. However, the low electrophilicity of the amide carbonyl group, high thermodynamic stability and kinetic inertness of the amides make their reduction a challenging task. Until recently, most efforts for catalytic deoxygenation of amides to amines were concentrated on hydrogenation and hydrosilylation approaches, which mainly employed precious metal catalysts and often required harsh reaction conditions and showed insufficient selectivities. Moreover, these reactions are mostly limited to secondary and tertiary amides, whereas direct reduction of primary amides to primary amines remained arduous. In contrast, deoxygenative hydroboration of amides, although it appeared less then a decade ago, has already proved advantageous in terms of the amide scope, reaction conditions and selectivity of transformations. This article provides an overview of the developments in hydroboration of amides, focusing on mechanistic aspects of these transformations and advantages of hydroboration compared to hydrogenation and hydrosilylation approaches.
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Affiliation(s)
- Andrey Y Khalimon
- Department of Chemistry, School of Sciences and Humanities, Nazarbayev University, 53 Kabanbay Batyr Avenue, Nur-Sultan 010000, Kazakhstan.
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10
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Kumar R, Bisai MK, Jain S, Vanka K, Sen SS. Deoxygenative hydroboration of primary and secondary amides: a catalyst-free and solvent-free approach. Chem Commun (Camb) 2021; 57:10596-10599. [PMID: 34568884 DOI: 10.1039/d1cc04148g] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In contrast to the recent reports on catalytic hydroboration of amides to amines with pinacolborane (HBpin), a simple catalyst-free and solvent-free method for the hydroboration of a variety of amides has been realized. To get the mechanistic insights, DFT calculations have been performed.
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Affiliation(s)
- Rohit Kumar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Milan Kumar Bisai
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Shailja Jain
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.,Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India.
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India.,Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India.
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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11
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Ohmura T, Morimasa Y, Ichino T, Miyake Y, Murata Y, Suginome M, Tajima K, Taketsugu T, Maeda S. Mechanism of 2,6-Dichloro-4,4′-bipyridine-Catalyzed Diboration of Pyrazines Involving a Bipyridine-Stabilized Boryl Radical. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Toshimichi Ohmura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yohei Morimasa
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Tomoya Ichino
- Department of Chemistry, Faculty of Science, Hokkaido University, N10-W8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Yusuke Miyake
- Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Yasujiro Murata
- Division of Synthetic Chemistry, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Michinori Suginome
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kunihiko Tajima
- Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, N10-W8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N21-W10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, N10-W8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, N21-W10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan
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12
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Nazish M, Legendre CM, Sarkar SK, Lücken J, Goffitzer DJ, Diefenbach M, Schwederski B, Herbst-Irmer R, Stalke D, Holthausen MC, Kaim W, Roesky HW. Selective Route to Stable Silicon-Boron Radicals and Their Corresponding Cations. Inorg Chem 2021; 60:10100-10104. [PMID: 34213317 DOI: 10.1021/acs.inorgchem.1c01438] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we report on a facile and selective one-pot synthetic route to silicon-boron radicals. Reduction of Br2BTip (Tip = 2,4,6-iPrC6H2) with KC8 in the presence of LSi-R affords LSi(tBu)-B(Br)Tip (1) and LSi(N(TMS)2)-B(Br)Tip (2) [L = PhC(NtBu)2]. These first examples of silicon-boron isolated radical species feature spin density on the silicon and boron atoms. 1 and 2 exhibit extraordinary stability to high temperatures under inert conditions in solution and air stability in the solid state. Both radicals have been isolated and fully characterized by electron paramagnetic resonance spectroscopy, SQUID magnetometry, mass spectrometry, cyclic voltammetry, single-crystal X-ray structure analysis, and density functional theory calculations. Moreover, compound 1 exhibits one-electron transfer when treated with 1 equiv of AgSO3CF3 and [Ph3C]+[B(C6F5)4]-, respectively, resulting in the corresponding cations [LSi(tBu)-B(Br)Tip]+[CF3SO3]- (3) and [LSi(tBu)-B(Br)Tip]+[B(C6F5)4]- (4). Compounds 3 and 4 have been characterized with multinuclear NMR and mass spectrometry.
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Affiliation(s)
- Mohd Nazish
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Christina M Legendre
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Samir Kumar Sarkar
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Jana Lücken
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Daniel J Goffitzer
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, Frankfurt am Main 60438, Germany
| | - Martin Diefenbach
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, Frankfurt am Main 60438, Germany
| | - Brigitte Schwederski
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
| | - Max C Holthausen
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, Frankfurt am Main 60438, Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany
| | - Herbert W Roesky
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, Göttingen 37077, Germany
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13
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Misal Castro LC, Sultan I, Nishi K, Tsurugi H, Mashima K. Direct Synthesis of Indoles from Azoarenes and Ketones with Bis(neopentylglycolato)diboron Using 4,4′-Bipyridyl as an Organocatalyst. J Org Chem 2021; 86:3287-3299. [DOI: 10.1021/acs.joc.0c02661] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Luis C. Misal Castro
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Ibrahim Sultan
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Kohei Nishi
- 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
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14
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Verma PK, Meher NK, Geetharani K. Homolytic cleavage of diboron(4) compounds using diazabutadiene derivatives. Chem Commun (Camb) 2021; 57:7886-7889. [PMID: 34302163 DOI: 10.1039/d1cc02881b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diazabutadiene derivatives have been identified as a distinct class of reagents, capable of cleaving B-B bonds of diboron(4). The cleavage is accompanied by the formation of a new C[double bond, length as m-dash]C bond and the product geometry is highly dependent on the substituents on the DAB units. Preliminary mechanistic investigations suggest a concerted mechanism and the absence of any radical intermediates.
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Affiliation(s)
- Piyush Kumar Verma
- Department of Inorganic and Physical Chemistry, Indian Institute of Science Bangalore, 560012, India.
| | - Naresh Kumar Meher
- Department of Inorganic and Physical Chemistry, Indian Institute of Science Bangalore, 560012, India.
| | - K Geetharani
- Department of Inorganic and Physical Chemistry, Indian Institute of Science Bangalore, 560012, India.
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15
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Gao L, Zhang H, Liu X, Wang G, Li S. Mechanistic insights into the dearomative diborylation of pyrazines: a radical or non-radical process? Dalton Trans 2021; 50:6982-6990. [DOI: 10.1039/d1dt00921d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanisms of the dearomative diborylation of pyrazines were investigated via a combination of density functional theory calculations and experimental studies.
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Affiliation(s)
- Liuzhou Gao
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education
- Institute of Theoretical and Computational Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Hanyin Zhang
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education
- Institute of Theoretical and Computational Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Xueting Liu
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education
- Institute of Theoretical and Computational Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Guoqiang Wang
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education
- Institute of Theoretical and Computational Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Shuhua Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education
- Institute of Theoretical and Computational Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
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16
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Dmitrienko A, Pilkington M, Britten JF, Gabidullin BM, Est A, Nikonov GI. Shedding Light on the Diverse Reactivity of NacNacAl with N‐Heterocycles. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anton Dmitrienko
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - Melanie Pilkington
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - James F. Britten
- Department of Chemistry & Biology McMaster University 1280 Main Street West Hamilton Ontario L8S 4L8 Canada
| | - Bulat M. Gabidullin
- X-Ray Core Facility University of Ottawa 150 Louis Pasteur Ottawa Ontario K1N 6N5 Canada
| | - Art Est
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
| | - Georgii I. Nikonov
- Chemistry Department Brock University 1812 Sir Isaac Brock Way St. Catharines Ontario L2S 3A1 Canada
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17
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Liu S, Légaré MA, Seufert J, Prieschl D, Rempel A, Englert L, Dellermann T, Paprocki V, Stoy A, Braunschweig H. 2,2′-Bipyridyl as a Redox-Active Borylene Abstraction Agent. Inorg Chem 2020; 59:10866-10873. [DOI: 10.1021/acs.inorgchem.0c01383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Siyuan Liu
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marc-André Légaré
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jens Seufert
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Dominic Prieschl
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Anna Rempel
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Lukas Englert
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Theresa Dellermann
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Valerie Paprocki
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Andreas Stoy
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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18
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Dmitrienko A, Pilkington M, Britten JF, Gabidullin BM, van der Est A, Nikonov GI. Shedding Light on the Diverse Reactivity of NacNacAl with N-Heterocycles. Angew Chem Int Ed Engl 2020; 59:16147-16153. [PMID: 32436289 DOI: 10.1002/anie.202005925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 01/09/2023]
Abstract
The aluminum(I) compound NacNacAl (NacNac=[ArNC(Me)CHC(Me)NAr]- , Ar=2,6-iPr2 C6 H3 , 1) shows diverse and substrate-controlled reactivity in reactions with N-heterocycles. 4-Dimethylaminopyridine (DMAP), a basic substrate in which the 4-position is blocked, induces rearrangement of NacNacAl by shifting a hydrogen atom from the methyl group of the NacNac backbone to the aluminum center. In contrast, C-H activation of the methyl group of 4-picoline takes place to produce a species with a reactive terminal methylene. Reaction of 1 with 3,5-lutidine results in the first example of an uncatalyzed, room-temperature cleavage of an sp2 C-H bond (in the 4-position) by an AlI species. Another reactivity mode was observed for quinoline, which undergoes 2,2'-coupling. Finally, the reaction of 1 with phthalazine produces the product of N-N bond cleavage.
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Affiliation(s)
- Anton Dmitrienko
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Melanie Pilkington
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - James F Britten
- Department of Chemistry & Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L8, Canada
| | - Bulat M Gabidullin
- X-Ray Core Facility, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5, Canada
| | - Art van der Est
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
| | - Georgii I Nikonov
- Chemistry Department, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario, L2S 3A1, Canada
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19
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Affiliation(s)
- Sehoon Park
- Department of ChemistryGuangdong Technion Israel Institute of Technology Guangdong 515063 P. R. China
- Technion-Israel Institute of Technology Technion City 32000 Haifa Israel
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20
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Li L, Wu Z, Zhu H, Robinson GH, Xie Y, Schaefer HF. Reduction of Dinitrogen via 2,3′-Bipyridine-Mediated Tetraboration. J Am Chem Soc 2020; 142:6244-6250. [DOI: 10.1021/jacs.0c00409] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Longfei Li
- College of Pharmacy, Hebei University, Baoding 071002, Hebei People’s Republic of China
| | - Zeyu Wu
- College of Pharmacy, Hebei University, Baoding 071002, Hebei People’s Republic of China
| | - Huajie Zhu
- College of Pharmacy, Hebei University, Baoding 071002, Hebei People’s Republic of China
| | - Gregory H. Robinson
- Department of Chemistry and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Yaoming Xie
- Department of Chemistry and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Henry F. Schaefer
- Department of Chemistry and Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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21
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Beagan DM, Carta V, Caulton KG. A reagent for heteroatom borylation, including iron mediated reductive deoxygenation of nitrate yielding a dinitrosyl complex. Dalton Trans 2020; 49:1681-1687. [PMID: 31956885 DOI: 10.1039/d0dt00077a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
4,4'-Bipyridyl is shown to be a catalyst for transfer of pinacolboryl groups from (Bpin)2 to nitrogen heterocycles and to Me3SiN3. Using stoichiometric (Bpin)2(pyrazine) or (Bpin)2(bipyridine) in an analogous manner, an aromatic nitro group is deoxygenated and subsequently borylated, and four-fold deoxygenation of (DIM)Fe(NO3)2(MeCN) to yield the dinitrosyl complex (DIM)Fe(NO)2 is facile. The co-product O(Bpin)2 is the quantitative fate of the removed oxo groups. With borylation of both nitrogen heterocycles and doubly deoxygenating two nitrates coordinated to a single metal center, broad spectrum methodology is demonstrated.
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Affiliation(s)
- Daniel M Beagan
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Veronica Carta
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
| | - Kenneth G Caulton
- Indiana University, Department of Chemistry, 800 E. Kirkwood Ave., Bloomington, IN 47401, USA.
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22
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Hosoya H, Misal Castro LC, Sultan I, Nakajima Y, Ohmura T, Sato K, Tsurugi H, Suginome M, Mashima K. 4,4′-Bipyridyl-Catalyzed Reduction of Nitroarenes by Bis(neopentylglycolato)diboron. Org Lett 2019; 21:9812-9817. [DOI: 10.1021/acs.orglett.9b03419] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Hiromu Hosoya
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Luis C. Misal Castro
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Ibrahim Sultan
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Yumiko Nakajima
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8565, Japan
| | - Toshimichi Ohmura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Kazuhiko Sato
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8565, Japan
| | - Hayato Tsurugi
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Michinori Suginome
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Kazushi Mashima
- Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
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23
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Beagan DM, Huerfano IJ, Polezhaev AV, Caulton KG. Reductive Silylation Using a Bis-silylated Diaza-2,5-cyclohexadiene. Chemistry 2019; 25:8105-8111. [PMID: 30994211 DOI: 10.1002/chem.201900879] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Indexed: 11/06/2022]
Abstract
1,4-Bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene, 1, was tested as a reagent for the reductive silylation of various unsaturated functionalities, including N-heterocycles, quinones, and other redox-active moieties in addition to deoxygenation of main group oxides. Whereas most reactions tested are thermodynamically favorable, based on DFT calculations, a few do not occur, perhaps giving limited insight on the mechanism of this very attractive reductive process. Of note, reductive silylation reactions show a strong solvent dependence where a polar solvent facilitates conversions.
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Affiliation(s)
- Daniel M Beagan
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - I J Huerfano
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | | | - Kenneth G Caulton
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
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24
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Morimasa Y, Kabasawa K, Ohmura T, Suginome M. Pyridine‐Based Organocatalysts for Regioselective
syn
‐1,2‐Silaboration of Terminal Alkynes and Allenes. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900176] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yohei Morimasa
- Department of Synthetic Chemistry and Biological ChemistryGraduate School of EngineeringKyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Kosuke Kabasawa
- Department of Synthetic Chemistry and Biological ChemistryGraduate School of EngineeringKyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Toshimichi Ohmura
- Department of Synthetic Chemistry and Biological ChemistryGraduate School of EngineeringKyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Michinori Suginome
- Department of Synthetic Chemistry and Biological ChemistryGraduate School of EngineeringKyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
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25
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Li Y, Wu M, Chen H, Xu D, Qu L, Zhang J, Bai R, Lan Y. Role of Alkaline-Earth Metal-Catalyst: A Theoretical Study of Pyridines Hydroboration. Front Chem 2019; 7:149. [PMID: 30972320 PMCID: PMC6443636 DOI: 10.3389/fchem.2019.00149] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 02/28/2019] [Indexed: 01/06/2023] Open
Abstract
Density functional theory (DFT) calculations have been performed to investigate the mechanism of alkaline-earth-metal-catalyzed hydroboration of pyridines with borane. In this reaction, the active catalytic species is considered to be an alkaline earth metal hydride complex when the corresponding alkaline earth metal is used as the catalyst. The theoretical results reveal that initiation of the catalytic cycle is hydride transfer to generate a magnesium hydride complex when β-diimine alkylmagnesium is used as a pre-catalyst. The magnesium hydride complex can undergo coordination of the pyridine reactant followed by hydride transfer to form a dearomatized magnesium pyridine intermediate. Coordination of borane and hydride transfer from borohydride to magnesium then give the hydroboration product and regenerate the active magnesium hydride catalyst. The rate-determining step of the catalytic cycle is hydride transfer to pyridine with a free energy barrier of 29.7 kcal/mol. Other alkaline earth metal complexes, including calcium and strontium complexes, were also considered. The DFT calculations show that the corresponding activation free energies for the rate-determining step of this reaction with calcium and strontium catalysts are much lower than with the magnesium catalyst. Therefore, calcium and strontium complexes can be used as the catalyst for the reaction, which could allow mild reaction conditions.
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Affiliation(s)
- Yuanyuan Li
- Department of Biological and Chemical Engineering, Chongqing University of Education, Chongqing, China.,Cooperative Innovation Center of Lipid Resources and Children's Daily Chemicals, Chongqing University of Education, Chongqing, China.,College of Chemistry and Molecular Engineering, ZhengZhou University, ZhengZhou, China
| | - Meijun Wu
- Department of Biological and Chemical Engineering, Chongqing University of Education, Chongqing, China
| | - Haohua Chen
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
| | - Dongdong Xu
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
| | - Lingbo Qu
- College of Chemistry and Molecular Engineering, ZhengZhou University, ZhengZhou, China
| | - Jing Zhang
- Department of Chemistry and Chemical Engineering, Jining University, Jining, China
| | - Ruopeng Bai
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
| | - Yu Lan
- College of Chemistry and Molecular Engineering, ZhengZhou University, ZhengZhou, China.,School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China
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26
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Shi Y, Gao Q, Xu S. NHC-Copper-Catalyzed Asymmetric Dearomative Silylation of Indoles. J Org Chem 2018; 83:14758-14767. [PMID: 30358397 DOI: 10.1021/acs.joc.8b02308] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We report an asymmetric dearomative silylation reaction of 3-acylindoles using a chiral NHC-copper(I) complex as catalyst to afford a range of cyclic α-aminosilanes with high regio- and enantioselectivity. Initial mechanistic studies revealed that the observed high diastereoselectivity was attributed to the facile epimerization of the 3-acyl group. We also demonstrated that the product could be used as a versatile precursor for the synthesis of functionalized indolines in high enantiomeric purity.
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Affiliation(s)
- Yongjia Shi
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute, Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences, Chinese Academy of Sciences , Lanzhou 73000 , China
| | - Qian Gao
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute, Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences, Chinese Academy of Sciences , Lanzhou 73000 , China
| | - Senmiao Xu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute, Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences, Chinese Academy of Sciences , Lanzhou 73000 , China.,Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education , Hangzhou Normal University , Hangzhou 311121 , P. R. China
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27
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Chen L, Shen JJ, Gao Q, Xu S. Synthesis of cyclic chiral α-amino boronates by copper-catalyzed asymmetric dearomative borylation of indoles. Chem Sci 2018; 9:5855-5859. [PMID: 30079199 PMCID: PMC6050576 DOI: 10.1039/c8sc01815d] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/08/2018] [Indexed: 01/19/2023] Open
Abstract
A copper(i)-catalyzed dearomative borylation of N-alkoxycarbonyl protected indole-3-carboxylates has been developed. The boron addition in this reaction occurred regioselectively at the 2-position of indoles followed by diastereoselective protonation, affording the corresponding stable cyclic chiral α-amino boronates (2-borylindolines) in moderate to good yields with excellent diastereo- and enantioselectivities. The product 2c could be used as a versatile precursor to undergo subsequent stereoselective transformations, delivering highly functionalized 2,3,3-trisubstituted chiral indolines.
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Affiliation(s)
- Lili Chen
- State Key Laboratory for Oxo Synthesis and Selective Oxidation , Centre for Excellence in Molecular Synthesis , Suzhou Research Institute , Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences , Chinese Academy of Sciences , Lanzhou 730000 , China .
| | - Jun-Jian Shen
- State Key Laboratory for Oxo Synthesis and Selective Oxidation , Centre for Excellence in Molecular Synthesis , Suzhou Research Institute , Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences , Chinese Academy of Sciences , Lanzhou 730000 , China .
| | - Qian Gao
- State Key Laboratory for Oxo Synthesis and Selective Oxidation , Centre for Excellence in Molecular Synthesis , Suzhou Research Institute , Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences , Chinese Academy of Sciences , Lanzhou 730000 , China .
| | - Senmiao Xu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation , Centre for Excellence in Molecular Synthesis , Suzhou Research Institute , Lanzhou Institute of Chemical Physics , University of Chinese Academy of Sciences , Chinese Academy of Sciences , Lanzhou 730000 , China .
- Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education , Hangzhou Normal University , Hangzhou 311121 , China
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28
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Noguchi M, Suzuki K, Kobayashi J, Yurino T, Tsurugi H, Mashima K, Yamashita M. Planar and Bent BN-Embedded p-Quinodimethanes Synthesized by Transmetalation of Bis(trimethylsilyl)-1,4-dihydropyrazines with Chloroborane. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00294] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Mao Noguchi
- Department of Applied Chemistry, Graduate School of Science and Engineering, Chuo University, 1-23-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Katsunori Suzuki
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya 464-8603, Japan
| | - Jun Kobayashi
- Department of Applied Chemistry, Graduate School of Science and Engineering, Chuo University, 1-23-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Taiga Yurino
- 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
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya 464-8603, Japan
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29
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Zhang L, Jiao L. Super electron donors derived from diboron. Chem Sci 2018; 9:2711-2722. [PMID: 29732055 PMCID: PMC5911971 DOI: 10.1039/c8sc00008e] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/28/2018] [Indexed: 01/02/2023] Open
Abstract
Single-electron transfer is an important process in organic chemistry, in which a single-electron reductant (electron donor) acts as a key component. Compared with metal-based electron donors, organic electron donors have some unique advantages, such as tunable reduction ability and mild reaction conditions. The development of novel organic electron donors with good reduction ability together with ease of preparation is in high demand. Based on the pyridine-catalyzed radical borylation reaction developed in our laboratory, we have discovered that, the reaction system consisting of a diboron(4) compound, methoxide and a pyridine derivative could smoothly produce super electron donors in situ. Two boryl-pyridine based species, the major one being a trans-2H,2'H-[2,2'-bipyridine]-1,1'-diide borate complex and the minor one being a pyridine radical anion-borate complex, were observed and carefully characterized. These complexes were found to be organic super electron donors unprecedented in literature, and their formation mechanisms were studied by DFT calculations. The diboron/methoxide/pyridine system enables the preparation of organic super electron donors from easily accessible starting materials under mild conditions, which has the potential to be a general and practical single-electron reducing agent in organic synthesis.
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Affiliation(s)
- Li Zhang
- Center of Basic Molecular Science (CBMS) , Department of Chemistry , Tsinghua University , Beijing 10084 , China .
| | - Lei Jiao
- Center of Basic Molecular Science (CBMS) , Department of Chemistry , Tsinghua University , Beijing 10084 , China .
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30
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Cuenca AB, Shishido R, Ito H, Fernández E. Transition-metal-free B-B and B-interelement reactions with organic molecules. Chem Soc Rev 2018; 46:415-430. [PMID: 27942683 DOI: 10.1039/c6cs00692b] [Citation(s) in RCA: 248] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This review is a guided tour along the activation modes and reactivity of B-B, B-Si, B-N, B-S, B-Se and B-P reagents, in the absence of any transition metal complex. Here are disclosed the general concepts related to the homolytic and heterolytic cleavage of B-B and B-interelement bonds, as well as the generation of new C-B and C-interelement bonds, in a selective way. The greener consequences of these novel routes facilitate the gram scale preparations of target functionalised organic compounds. Intrinsic data about the suggested mechanisms and spectroscopic evidence that supports the innovative theories are provided along the review. Since this is a stimulating area of work that has emerged within the last decade, this overview serves as the basis to understand the new trends and hopefully to generate inspiration for future discoveries in the field.
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Affiliation(s)
- Ana B Cuenca
- Dept Física Química e Inorgánica, University Rovira i Virgili, C/Marcel·lí Domingo s/n, 43007 Tarragona, Spain. and Dept. Química Orgánica, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta, 390, Barcelona 08017, Spain
| | - Ryosuke Shishido
- Division of Chemical Process Engineering, Graduate School of Engineering Hokkaido University, Sapporo, 060-8628, Japan.
| | - Hajime Ito
- Division of Chemical Process Engineering, Graduate School of Engineering Hokkaido University, Sapporo, 060-8628, Japan.
| | - Elena Fernández
- Dept Física Química e Inorgánica, University Rovira i Virgili, C/Marcel·lí Domingo s/n, 43007 Tarragona, Spain.
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31
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Katsuma Y, Asakawa H, Yamashita M. Reactivity of highly Lewis acidic diborane(4) towards pyridine and isocyanide: formation of boraalkene-pyridine complex and ortho-functionalized pyridine derivatives. Chem Sci 2018; 9:1301-1310. [PMID: 29675176 PMCID: PMC5887101 DOI: 10.1039/c7sc04759b] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/10/2017] [Indexed: 12/14/2022] Open
Abstract
The reaction of pinB-BMes2 (pin = pinacolato, Mes = 2,4,6-Me3C6H2) with Xyl-NC (Xyl = 2,6-Me2C6H3) and pyridine results in the formation of a pyridine-coordinated boraalkene that exhibits an intense color caused by an intramolecular charge-transfer interaction. In the presence of an excess of pyridine, the ortho C-H bond of pyridine was selectively functionalized to afford a quinoid compound or an isocyanide-coupled product. Based on the concentration effect, the reaction stoichiometry, and previously reported DFT calculations, a reaction mechanism that involves several rearrangement reactions was proposed. Using the present method, substituted pyridines and N-heterocycles afforded the corresponding functionalized derivatives. A subsequent hydrolysis of one of the resulting products furnished an aminomethylated pyridine derivative in two steps from parent pyridine.
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Affiliation(s)
- Yuhei Katsuma
- Department of Applied Chemistry , Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , 112-8551 , Tokyo , Japan
| | - Hiroki Asakawa
- Department of Applied Chemistry , Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , 112-8551 , Tokyo , Japan
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , 464-8603 , Aichi , Japan .
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32
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Ohmura T, Morimasa Y, Suginome M. 4,4′-Bipyridine-catalyzed Stereoselective trans-Diboration of Acetylenedicarboxylates to 2,3-Diborylfumarates. CHEM LETT 2017. [DOI: 10.1246/cl.170848] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Toshimichi Ohmura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510
| | - Yohei Morimasa
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510
| | - Michinori Suginome
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510
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33
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Lortie JL, Dudding T, Gabidullin BM, Nikonov GI. Zinc-Catalyzed Hydrosilylation and Hydroboration of N-Heterocycles. ACS Catal 2017. [DOI: 10.1021/acscatal.7b02811] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John L. Lortie
- Department
of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Travis Dudding
- Department
of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
| | - Bulat M. Gabidullin
- X-ray
Core Facility, Faculty of Science, University of Ottawa, 150 Louis
Pasteur, Ottawa, Ontario K1N 6N5, Canada
| | - Georgii I. Nikonov
- Department
of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada
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34
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Yan G, Huang D, Wu X. Recent Advances in C-B Bond Formation through a Free Radical Pathway. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201701030] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Guobing Yan
- Department of Chemistry; Lishui University; No. 1, Xueyuan Road Lishui City 323000 People's Republic of China
| | - Dayun Huang
- Department of Chemistry; Lishui University; No. 1, Xueyuan Road Lishui City 323000 People's Republic of China
| | - Xiangmei Wu
- Department of Chemistry; Lishui University; No. 1, Xueyuan Road Lishui City 323000 People's Republic of China
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35
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Geier SJ, Vogels CM, Mellonie NR, Daley EN, Decken A, Doherty S, Westcott SA. The Phosphinoboration ofN-Heterocycles. Chemistry 2017; 23:14485-14499. [DOI: 10.1002/chem.201702203] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Stephen J. Geier
- Department of Chemistry and Biochemistry; Mount Allison University; Sackville NB E4L 1G8 Canada
| | - Christopher M. Vogels
- Department of Chemistry and Biochemistry; Mount Allison University; Sackville NB E4L 1G8 Canada
| | - Niall R. Mellonie
- NUCAT, School of Chemistry, Bedson Building; Newcastle University; Newcastle upon Tyne NE1 7RU England
| | - Erika N. Daley
- Department of Chemistry and Biochemistry; Mount Allison University; Sackville NB E4L 1G8 Canada
| | - Andreas Decken
- Department of Chemistry; University of New Brunswick; Fredericton NB E3B 5A3 Canada
| | - Simon Doherty
- NUCAT, School of Chemistry, Bedson Building; Newcastle University; Newcastle upon Tyne NE1 7RU England
| | - Stephen A. Westcott
- Department of Chemistry and Biochemistry; Mount Allison University; Sackville NB E4L 1G8 Canada
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36
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Arévalo R, Vogels CM, MacNeil GA, Riera L, Pérez J, Westcott SA. Rhenium-catalysed hydroboration of aldehydes and aldimines. Dalton Trans 2017; 46:7750-7757. [DOI: 10.1039/c7dt01549f] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The first examples of the catalysed hydroboration of aldehydes and aldimines using low- and high-valent rhenium complexes are reported.
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Affiliation(s)
- Rebeca Arévalo
- Departamento de Química Orgánica e Inorgánica
- Universidad de Oviedo
- Oviedo
- Spain
| | | | - Gregory A. MacNeil
- Department of Chemistry and Biochemistry
- Mount Allison University
- Sackville
- Canada
| | - Lucía Riera
- Centro de Investigación en Nanomateriales y Nanotecnología (CINN)
- CSIC-Universidad de Oviedo-Principado de Asturias
- El Entrego
- Spain
| | - Julio Pérez
- Departamento de Química Orgánica e Inorgánica
- Universidad de Oviedo
- Oviedo
- Spain
- Centro de Investigación en Nanomateriales y Nanotecnología (CINN)
| | - Stephen A. Westcott
- Department of Chemistry and Biochemistry
- Mount Allison University
- Sackville
- Canada
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37
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Neeve EC, Geier SJ, Mkhalid IAI, Westcott SA, Marder TB. Diboron(4) Compounds: From Structural Curiosity to Synthetic Workhorse. Chem Rev 2016; 116:9091-161. [PMID: 27434758 DOI: 10.1021/acs.chemrev.6b00193] [Citation(s) in RCA: 732] [Impact Index Per Article: 91.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although known for over 90 years, only in the past two decades has the chemistry of diboron(4) compounds been extensively explored. Many interesting structural features and reaction patterns have emerged, and more importantly, these compounds now feature prominently in both metal-catalyzed and metal-free methodologies for the formation of B-C bonds and other processes.
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Affiliation(s)
- Emily C Neeve
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg 97074, Germany
| | - Stephen J Geier
- Mount Allison University , Department of Biochemistry and Chemistry, Sackville, New Brunswick E4L 1G8, Canada
| | | | - Stephen A Westcott
- Mount Allison University , Department of Biochemistry and Chemistry, Sackville, New Brunswick E4L 1G8, Canada
| | - Todd B Marder
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg 97074, Germany
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38
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Rakhi R, Suresh CH. A DFT study on dihydropyrazine annulated linear polyacenes: aromaticity, stability and HOMO–LUMO energy modulation. Phys Chem Chem Phys 2016; 18:24631-41. [DOI: 10.1039/c6cp03723b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Linear polyacene (LPA) mimics containing up to 34 rings have been designed by annulating dihydropyrazine units to LPA cores and they showed enhanced aromatic character than the LPA due to significant mixing of the N-lone pairs with the carbon π-orbitals.
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Affiliation(s)
- Ramachandran Rakhi
- Chemical Sciences and Technology Division
- Academy of Scientific and Innovative Research (AcSIR)
- CSIR–National Institute for Interdisciplinary Science and Technology (CSIR–NIIST)
- Thiruvananthapuram 695019
- India
| | - Cherumuttathu H. Suresh
- Chemical Sciences and Technology Division
- Academy of Scientific and Innovative Research (AcSIR)
- CSIR–National Institute for Interdisciplinary Science and Technology (CSIR–NIIST)
- Thiruvananthapuram 695019
- India
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39
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Hong S, Zhang W, Liu M, Yao ZJ, Deng W. Transition-metal-free hydroboration of terminal alkynes activated by base. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2015.09.077] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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40
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López A, Parra A, Jarava-Barrera C, Tortosa M. Copper-catalyzed silylation of p-quinone methides: new entry to dibenzylic silanes. Chem Commun (Camb) 2015; 51:17684-7. [PMID: 26490453 PMCID: PMC4847169 DOI: 10.1039/c5cc06653k] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/12/2015] [Indexed: 02/04/2023]
Abstract
An efficient and general copper(I)-catalyzed silylation of p-quinone-methides is described. Non-symmetric dibenzylic silanes are obtained in high yields under mild reaction conditions. These compounds can be used as bench-stable benzylic carbanion precursors.
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Affiliation(s)
- Aurora López
- Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco, 28049 Madrid, Spain.
| | - Alejandro Parra
- Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco, 28049 Madrid, Spain.
| | - Carlos Jarava-Barrera
- Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco, 28049 Madrid, Spain.
| | - Mariola Tortosa
- Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco, 28049 Madrid, Spain.
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41
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Yoshimura A, Takamachi Y, Han L, Ogawa A. Organosulfide‐Catalyzed Diboration of Terminal Alkynes under Light. Chemistry 2015; 21:13930-3. [DOI: 10.1002/chem.201502425] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Aya Yoshimura
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1‐1 Gakuen‐cho, Nakaku, Sakai, Osaka 599‐8531 (Japan)
- National Institute of Advanced Industrial Science and Technology (AIST), 1‐1‐1, Higashi, Tsukuba, Ibaraki, 305‐8565 (Japan)
| | - Yuki Takamachi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1‐1 Gakuen‐cho, Nakaku, Sakai, Osaka 599‐8531 (Japan)
| | - Li‐Biao Han
- National Institute of Advanced Industrial Science and Technology (AIST), 1‐1‐1, Higashi, Tsukuba, Ibaraki, 305‐8565 (Japan)
| | - Akiya Ogawa
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1‐1 Gakuen‐cho, Nakaku, Sakai, Osaka 599‐8531 (Japan)
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42
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Dewhurst RD, Neeve EC, Braunschweig H, Marder TB. sp(2)-sp(3) diboranes: astounding structural variability and mild sources of nucleophilic boron for organic synthesis. Chem Commun (Camb) 2015; 51:9594-607. [PMID: 25912808 DOI: 10.1039/c5cc02316e] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the widespread use of organoborane reagents in organic synthesis and catalysis, a major challenge still remains: very few boron-centered nucleophiles exist for the direct construction of B-C bonds. Perhaps the most promising emerging solution to this problem is the use of sp(2)-sp(3) diboranes, in which one boron atom of a conventional diborane(4) is quaternised by either a neutral or anionic nucleophile. These compounds, either isolated or generated in situ, serve as relatively mild and convenient sources of the boryl anion [BR2](-) for use in organic synthesis and have already proven their efficacy in metal-free as well as metal-catalysed borylation reactions. This Feature article documents the history of sp(2)-sp(3) diborane synthesis, their properties and surprising structural variability, and their burgeoning utility in organic synthesis.
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Affiliation(s)
- Rian D Dewhurst
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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43
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Intemann J, Bauer H, Pahl J, Maron L, Harder S. Calcium Hydride Catalyzed Highly 1,2‐Selective Pyridine Hydrosilylation. Chemistry 2015; 21:11452-61. [DOI: 10.1002/chem.201501072] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Julia Intemann
- Stratingh Institute for Chemistry, Nijenborgh 4, 9747AG Groningen (The Netherlands)
| | - Heiko Bauer
- Friedrich‐Alexander University Erlangen‐Nürnberg, Inorganic and Organometallic Chemistry, Egerlandstraße 1, 91058 Erlangen (Germany)
| | - Jürgen Pahl
- Friedrich‐Alexander University Erlangen‐Nürnberg, Inorganic and Organometallic Chemistry, Egerlandstraße 1, 91058 Erlangen (Germany)
| | - Laurent Maron
- Université de Toulouse et CNRS INSA, UPS, CNRS, UMR 5215, LPCNO, 135 avenue de Rangueil, 31077 Toulouse (France)
| | - Sjoerd Harder
- Friedrich‐Alexander University Erlangen‐Nürnberg, Inorganic and Organometallic Chemistry, Egerlandstraße 1, 91058 Erlangen (Germany)
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44
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Pietsch S, Neeve EC, Apperley DC, Bertermann R, Mo F, Qiu D, Cheung MS, Dang L, Wang J, Radius U, Lin Z, Kleeberg C, Marder TB. Synthesis, Structure, and Reactivity of Anionic sp2-sp3Diboron Compounds: Readily Accessible Boryl Nucleophiles. Chemistry 2015; 21:7082-98. [DOI: 10.1002/chem.201500235] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Indexed: 01/20/2023]
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45
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Yamamoto E, Ukigai S, Ito H. Boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with silylborane and an alkoxy base: expanded scope and mechanistic studies. Chem Sci 2015; 6:2943-2951. [PMID: 29308171 PMCID: PMC5656038 DOI: 10.1039/c5sc00384a] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 03/02/2015] [Indexed: 01/01/2023] Open
Abstract
A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides using a silylborane/alkoxy-base reagent. Borylation of (Z)-alkenyl halides proceeded in a stereoretentive manner.
A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with a silylborane in the presence of an alkali-metal alkoxide. The base-mediated boryl substitution of organohalides with a silylborane was recently reported to provide the corresponding borylated products in good to high yields, and exhibit good functional group compatibility and high tolerance to steric hindrance. In this study, the scope of this transformation has been extended significantly to include a wide variety of functionalized aryl-, heteroaryl- and alkenyl halides. In particular, the boryl substitution of (E)- and (Z)-alkenyl halides proceeded smoothly to afford the corresponding alkenyl boronates in good to high yields with retention of the configuration using modified reaction conditions. The results of the mechanistic studies suggest that this boryl substitution proceeds via a carbanion-mediated mechanism.
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Affiliation(s)
- Eiji Yamamoto
- Division of Chemical Process Engineering and Frontier Chemistry Center , Faculty of Engineering , Hokkaido University , Sapporo 060-8628 , Japan .
| | - Satoshi Ukigai
- Division of Chemical Process Engineering and Frontier Chemistry Center , Faculty of Engineering , Hokkaido University , Sapporo 060-8628 , Japan .
| | - Hajime Ito
- Division of Chemical Process Engineering and Frontier Chemistry Center , Faculty of Engineering , Hokkaido University , Sapporo 060-8628 , Japan .
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46
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Ohmura T, Morimasa Y, Suginome M. Organocatalytic Diboration Involving “Reductive Addition” of a Boron–Boron σ-Bond to 4,4′-Bipyridine. J Am Chem Soc 2015; 137:2852-5. [DOI: 10.1021/jacs.5b00546] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Toshimichi Ohmura
- Department of Synthetic Chemistry
and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yohei Morimasa
- Department of Synthetic Chemistry
and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Michinori Suginome
- Department of Synthetic Chemistry
and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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47
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Daley EN, Vogels CM, Geier SJ, Decken A, Doherty S, Westcott SA. The phosphinoboration reaction. Angew Chem Int Ed Engl 2014; 54:2121-5. [PMID: 25558017 DOI: 10.1002/anie.201410033] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Indexed: 11/09/2022]
Abstract
The synthesis of phosphinoboronate esters containing a single P-B bond is reported, together with preliminary reactivity studies towards a range of organic substrates. These compounds add readily to aldehydes, ketones, aldimines, and α,β-unsaturated enones to give primarily the corresponding 1,2-addition products containing a new P-C bond. The first examples of transition-metal-catalyzed phosphinoborations of C-C multiple bonds in which P-C and B-C bonds are formed in a single step are also disclosed; allenes react by a highly regioselective 1,2-addition whereas terminal alkynes undergo a formal 1,1-addition.
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Affiliation(s)
- Erika N Daley
- Department of Chemistry and Biochemistry, Mount Allison University, 63C York Street, Sackville, New Brunswick, E4L 1G8 (Canada) http://thewildtoads.com/
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48
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Daley EN, Vogels CM, Geier SJ, Decken A, Doherty S, Westcott SA. The Phosphinoboration Reaction. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201410033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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49
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Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst. Nat Chem 2014; 6:1100-7. [PMID: 25411889 DOI: 10.1038/nchem.2087] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/12/2014] [Indexed: 12/22/2022]
Abstract
Developing earth-abundant, non-platinum metal catalysts for high-value chemical transformations is a critical challenge to contemporary chemical synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar reagent stoichiometry. Regarding the mechanism, derivation of the rate law from NMR spectroscopic and kinetic measurements suggests first order in catalyst concentration, fractional order in pyridine concentration and inverse first order in pinacolborane concentration, with C=N insertion into the La-H bond as turnover-determining. An energetic span analysis affords a more detailed understanding of experimental activity trends and the unusual kinetic behaviour, and proposes the catalyst 'resting' state and potential deactivation pathways.
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50
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Intemann J, Lutz M, Harder S. Multinuclear Magnesium Hydride Clusters: Selective Reduction and Catalytic Hydroboration of Pyridines. Organometallics 2014. [DOI: 10.1021/om500469h] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Julia Intemann
- Stratingh Institute for Chemistry, Nijenborgh 4, 9747AG Groningen, The Netherlands
- Inorganic and Organometallic Chemistry, Friedrich-Alexander University Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Martin Lutz
- Bijvoet Center for Biomolecular
Research, Crystal
and Structural Chemistry, Padualaan 8, 3584CH Utrecht, The Netherlands
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander University Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
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