- Cu-mediated: vs. Cu-free selective borylation of aryl alkyl sulfones
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A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds
- Hu, Jiefeng,Huang, Mingming,Marder, Todd B.,Radius, Udo,Tang, Man,Westcott, Stephen A.
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supporting information
p. 395 - 398
(2022/01/19)
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- Mono-Phosphine Metal-Organic Framework-Supported Cobalt Catalyst for Efficient Borylation Reactions
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We report a metal-organic framework (MOF) supported monoligated phosphine-cobalt complex, which is an active heterogeneous catalyst for aromatic C?H borylation and alkene hydroboration. The mono(phosphine)-Co catalyst (MOF?P?Co) was prepared by metalation of a porous triarylphosphine-functionalized MOF (MOF?P) with CoCl2 followed by activation with NaEt3BH. The MOF catalyst has a broad substrate scope with excellent functional group tolerance to afford arene- and alkyl-boronate esters in excellent yields and selectivity. MOF?P?Co gave a turnover number (TON) of 30,000 and could be recycled and reused at least 13 times in arene C?H borylation. Importantly, the attempt to prepare the homogeneous control (Ph3P?Co) using triphenylphosphine was unsuccessful due to the facile disproportionation reactions or intermolecular ligand exchanges in the solution. In contrast, the site isolation of the active mono(phosphine)-Co species within the MOF affords the robust and coordinatively unsaturated metal complexes, allowing to explore their catalytic properties and the reaction mechanism.
- Akhtar, Naved,Antil, Neha,Balendra,Begum, Wahida,Chauhan, Manav,Gupta, Poorvi,Kumar, Ajay,Malik, Jaideep,Manna, Kuntal,Newar, Rajashree
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supporting information
(2022/03/15)
-
- Photochemical and electrochemical C-N borylation of arylhydrazines
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The C-N borylation of arylhydrazine hydrochlorides with bis(pinacolato)diboron was achieved under photochemical and electrochemical conditions, respectively. This novel and scalable transformation provides two efficient and mild transition-metal-free synt
- Du, Linlin,Sun, Li,Zhang, Hua
-
supporting information
p. 1716 - 1719
(2022/02/21)
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- Remote steric control for undirected meta-selective C-H activation of arenes
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Regioselective functionalization of arenes remains a challenging problem in organic synthesis. Steric interactions are often used to block sites adjacent to a given substituent, but they do not distinguish the remaining remote sites. We report a strategy
- Asako, Sobi,Ilies, Laurean,Jin, Yushu,Ramadoss, Boobalan
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p. 658 - 663
(2022/02/21)
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- Unreactive C-N Bond Activation of Anilines via Photoinduced Aerobic Borylation
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Unreactive C-N bond activation of anilines was achieved by photoinduced aerobic borylation. A diverse range of tertiary and secondary anilines were converted to aryl boronate esters in moderate to good yields with wide functional group tolerance under simple and ambient photochemical conditions. This transformation achieved the direct and facile C-N bond activation of unreactive anilines, providing a convenient and practical route transforming widely available anilines into useful aryl boronate esters.
- Ji, Shuohan,Qin, Shengxiang,Yin, Chunyu,Luo, Lu,Zhang, Hua
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supporting information
p. 64 - 68
(2021/12/27)
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- Palladium-catalyzed borylation of aryl bromides and chlorides using phosphatrioxa-adamantane ligands
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Catalysts based on the combination of Pd(OAc)2 and the electron-deficient phosphatrioxa-adamantane ligands are described for borylation of aryl bromides and chlorides. Catalytic evaluation of a small library of phosphatrioxa-adamantane ligands provided some insights on the preferred ligand steric profile for borylation reactions. The corresponding aryl boronate esters were accessed under mild conditions (25–70 °C) and isolated in high yields (up to 96%).
- Lamola, Jairus L.,Moshapo, Paseka T.,Holzapfel, Cedric W.,Christopher Maumela, Munaka
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supporting information
(2021/12/13)
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- Method for catalytically synthesizing phenylboronic acid ester derivative by iridium catalyst
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The invention relates to a method for catalytically synthesizing a phenylboronic acid ester derivative by using an iridium catalyst. The method comprises the following steps: by using a cyclooctadieneiridium chloride dimer as a catalyst, dissolving aryl halide and pinacol borane in an organic solvent to react, and carrying out aftertreatment to obtain the phenylboronic acid ester derivative. Compared with the prior art, the method has the advantages that the method is simple and green, cheap, readily available and stable raw materials of aryl halide and pinacol borane are used, the reaction conditions are mild, corresponding products can be obtained at high yield through reaction at room temperature in a non-inert atmosphere, and the method has good substrate universality, so that the method is better convenient to apply.
- -
-
Paragraph 0030-0033
(2021/01/11)
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- Catalytic Boration of Alkyl Halides with Borane without Hydrodehalogenation Enabled by Titanium Catalyst
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An unprecedented and general titanium-catalyzed boration of alkyl (pseudo)halides (alkyl-X, X=I, Br, Cl, OMs) with borane (HBpin, HBcat) is reported. The use of titanium catalyst can successfully suppress the undesired hydrodehalogenation products that prevail using other transition-metal catalysts. A series of synthetically useful alkyl boronate esters are readily obtained from various (primary, secondary, and tertiary) alkyl electrophiles, including unactivated alkyl chlorides, with tolerance of other reducing functional groups such as ester, alkene, and carbamate. Preliminary studies on the mechanism revealed a possible radical reaction pathway. Further extension of our strategy to aryl bromides is also demonstrated.
- Wang, Xianjin,Cui, Penglei,Xia, Chungu,Wu, Lipeng
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supporting information
p. 12298 - 12303
(2021/05/07)
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- The functionalization of benzene by boranes using trispyrazolylborate complexes
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The catalytic C[sbnd]H activation and borylation of arenes by trispyrazolylborate complexes is reported. Trispyrazolylborate rhodium and iridium complexes have been previously shown to activate a variety of C[sbnd]H bonds. Here, we show the catalytic borylation of arenes by the trispyrazolylborate ethylene complexes Tp'Rh(C2H4)2, and Tp'Ir(C2H4)2.
- Vetter, Andrew J.,DiBenedetto, Tarah A.,Ritz, Mikhaila D.,Jones, William D.
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- Carbon-carbon bond activation by B(OMe)3/B2pin2-mediated fragmentation borylation
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Selective carbon-carbon bond activation is important in chemical industry and fundamental organic synthesis, but remains challenging. In this study, non-polar unstrained Csp2-Csp3 and Csp2-Csp2 bond activation was achieved by B(OMe)3/B2pin2-mediated fragmentation borylation. Various indole derivatives underwent C2-regioselective C-C bond activation to afford two C-B bonds under transition-metal-free conditions. Preliminary mechanistic investigations suggested that C-B bond formation and C-C bond cleavage probably occurred in a concerted process. This new reaction mode will stimulate the development of reactions based on inert C-C bond activation. This journal is
- Chen, Quan,Jiang, Jiachen,Wang, Li,Wu, Aizhen,Yin, Youzhi,Zhang, Hua,Zhang, Ke,Zhao, Mengzhen,Zhong, Qi,Zou, Youliang
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p. 15104 - 15109
(2021/12/09)
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- Synthesis of arylboronates via the Pd-catalyzed desulfitative coupling reaction of sodium arylsulfinates with bis(pinacolato)diboron
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The desulfitative borylation reaction of sodium arylsulfinates with bis(pinacolato)diboron or bis(neopentylglycolato)diboron under palladium catalysis has been developed, allowing selective C-B bond formation to give arylboronates with a range of functional groups in moderate to good yields under mild reaction conditions. A gram-scale preparation as well as the cascade Suzuki-Miyaura cross-coupling of arylboronates demonstrated the potential practical utility in organic synthesis.
- Qiu, Di,Li, Songyi,Yue, Guanglu,Mao, Jinshan,Xu, Bei,Yuan, Xinyu,Ye, Fei
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supporting information
(2021/11/04)
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- Photo-induced thiolate catalytic activation of inert Caryl-hetero bonds for radical borylation
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Substantial effort is currently being devoted to obtaining photoredox catalysts with high redox power. Yet, it remains challenging to apply the currently established methods to the activation of bonds with high bond dissociation energy and to substrates with high reduction potentials. Herein, we introduce a novel photocatalytic strategy for the activation of inert substituted arenes for aryl borylation by using thiolate as a catalyst. This catalytic system exhibits strong reducing ability and engages non-activated Caryl–F, Caryl–X, Caryl–O, Caryl–N, and Caryl–S bonds in productive radical borylation reactions, thus expanding the available aryl radical precursor scope. Despite its high reducing power, the method has a broad substrate scope and good functional-group tolerance. Spectroscopic investigations and control experiments suggest the formation of a charge-transfer complex as the key step to activate the substrates.
- K?nig, Burkhard,Wang, Hua,Wang, Shun
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supporting information
p. 1653 - 1665
(2021/06/17)
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- METHOD FOR SYNTHESIZING BORONATE ESTER COMPOUND, SODIUM SALT OF BORONATE ESTER COMPOUND, AND METHOD FOR SYNTHESIZING THE SAME
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An object is to establish a technology with which a boronate ester compound can be easily and efficiently synthesized at a low cost with a small number of steps without the need for a complex chemical method and reagents that need to be carefully handled. A further object is to establish a sodium salt of a boronate ester compound that is a novel compound and a technology for synthesizing the sodium salt of a boronate ester compound. Provided are a sodium salt of a boronate ester compound and a method for synthesizing a boronate ester compound or a sodium salt of a boronate ester compound that includes reacting, in a reaction solvent, an organic chloride with a dispersion product obtained by dispersing sodium in a dispersion solvent to obtain an organic sodium compound, and reacting the obtained organic sodium compound with a borate ester compound to obtain a boronate ester compound or a sodium salt of a boronate ester compound.
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Paragraph 0115
(2021/03/13)
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- Improvement in the Palladium-Catalyzed Miyaura Borylation Reaction by Optimization of the Base: Scope and Mechanistic Study
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Aryl boronic acids and esters are important building blocks in API synthesis. The palladium-catalyzed Suzuki-Miyaura borylation is the most common method for their preparation. This paper describes an improvement of the current reaction conditions. By using lipophilic bases such as potassium 2-ethyl hexanoate, the borylation reaction could be achieved at 35 °C in less than 2 h with very low palladium loading (0.5 mol %). A preliminary mechanistic study shows a hitherto unrecognized inhibitory effect by the carboxylate anion on the catalytic cycle, whereas 2-ethyl hexanoate minimizes this inhibitory effect. This improved methodology enables borylation of a wide range of substrates under mild conditions.
- Barroso, Santiago,Joksch, Markus,Puylaert, Pim,Tin, Sergey,Bell, Stephen J.,Donnellan, Luke,Duguid, Stewart,Muir, Colin,Zhao, Peichao,Farina, Vittorio,Tran, Duc N.,De Vries, Johannes G.
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supporting information
p. 103 - 109
(2020/12/22)
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- Arene borylation through C–H activation using Cu3(BTC)2 as heterogeneous catalyst
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C–H borylation by diborane is an important process to access organoboron compounds. Noble metals, including Ir and Rh-based complexes either in the form of homogeneous or heterogeneous catalysts, have been reported to promote arene C–H borylation. Recently, metal organic frameworks (MOFs) having Ir and Co as active sites have been used as catalysts, but they require co-catalysts. In the present study, commercially available Cu3(BTC)2 (BTC: 1,3,5-benzenetricarboxylate) MOF is reported as an effective catalyst to promote borylation of arenes through C–H activation employing bis(pinacolato)diboron (1) as reagent leading to benzylic and aromatic borylation products. Interestingly, other related MOFs like MIL-101(Cr) and Al(OH)(BDC) (BDC: 1,4-benzenedicarboxylate) do not exhibit catalytic activity under identical conditions. Mechanistic studies using in-situ IR spectroscopy reveal that Cu ions play a crucial role in activating the arene and B–B bond in 1.
- Dhakshinamoorthy, Amarajothi,García, Cristina Vallés,Concepcion, Patricia,Garcia, Hermenegildo
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p. 212 - 217
(2020/07/06)
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- Light- and Manganese-Initiated Borylation of Aryl Diazonium Salts: Mechanistic Insight on the Ultrafast Time-Scale Revealed by Time-Resolved Spectroscopic Analysis
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Manganese-mediated borylation of aryl/heteroaryl diazonium salts emerges as a general and versatile synthetic methodology for the synthesis of the corresponding boronate esters. The reaction proved an ideal testing ground for delineating the Mn species responsible for the photochemical reaction processes, that is, involving either Mn radical or Mn cationic species, which is dependent on the presence of a suitably strong oxidant. Our findings are important for a plethora of processes employing Mn-containing carbonyl species as initiators and/or catalysts, which have considerable potential in synthetic applications.
- Firth, James D.,Hammarback, L. Anders,Burden, Thomas J.,Eastwood, Jonathan B.,Donald, James R.,Horbaczewskyj, Chris S.,McRobie, Matthew T.,Tramaseur, Adam,Clark, Ian P.,Towrie, Michael,Robinson, Alan,Krieger, Jean-Philippe,Lynam, Jason M.,Fairlamb, Ian J. S.
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supporting information
p. 3979 - 3985
(2021/02/03)
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- Zinc Complexes with an Ethylene-Bridged Bis(β-diketiminate) Ligand: Syntheses, Structures, and Applications as Catalysts in the Borylation of Aryl Iodides
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A dinucleating bis(β-diketiminate) ligand with a flexible bridge has been employed to synthesize zinc complexes. The ligand, abbreviated H2L (H2L = N-(4-((2-((4-((2,6-diisopropylphenyl)imino)pent-2-en-2-yl)amino)ethyl)imino)pent-2-en-2-yl)-2,6-diisopropylaniline), was deprotonated with ZnEt2 to afford [LZn2Et2] (1). Reactions of 1 with 2 equiv of BnOH and nBuOH, respectively, gave access to [LZn2(OBn)2]·C6H14 (2·C6H14) and [LZn2(OnBu)2] (3). Treatment of 1 with 2 equiv of I2 in THF produced [LZn2I2(THF)2]·2THF (4·2THF). X-ray single-crystal diffraction analyses revealed that they are all heteroleptic bimetallic compounds with two metal centers being chelated by one ligand set. The structurally similar compounds 1 and 4·2THF possess approximate C2 symmetry, with two β-diketiminate units being arrayed in head-to-tail antiparallel mode. Thus, the molecular structures of 1 and 4·2THF exhibit a seesaw-like topology. The structures of 2·C6H14 and 3 are almost identical, in which two zinc atoms are shared by two ZnN2C3 six-membered rings, two Zn2ON2C2 seven-membered rings, and one Zn2O2 four-membered ring. Therefore, the metal cores of 2·C6H14 and 3 display a crownlike topology. All complexes are catalytically active for the borylation of aryl iodides with B2Pin2 (B2Pin2 = 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bis(1,3,2-dioxaborolane). Complex 1 shows higher activity in comparison to 2, 3, and 4·2THF. The borylation reactions catalyzed by 1 could proceed under mild conditions and can be applied to a series of substrates with high functional group generality. This methodology thus represents a novel use of β-diketiminate zinc complexes for C-I borylation.
- Li, Yafei,Dang, Yan,Li, Dawei,Pan, Huifen,Zhang, Liang,Wang, Li,Cao, Zhu,Li, Yahong
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supporting information
p. 482 - 489
(2021/03/01)
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- Engaging Ag(0) single atoms in silver(I) salts-mediated C-B and C-S coupling under visible light irradiation
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Silver(I) salts were found active in the borylation and sulfenylation of aryl iodides under visible light irradiation. The optimized borylation protocol using AgF did not need any additive, operated under very mild conditions, and well tolerated a broad scope of substrates and boron sources. Formation of Ag(0) single atoms (AgSAs) during the borylation reactions was examined using high-angle annular dark field aberration-corrected scanning transmission electron microscope (HAADF AC-STEM) and electron paramagnetic resonance (EPR). The activities of the silver(I) salts were affected by the anions and could be associated with their abilities in formation of AgSAs during the reactions. Kinetic studies showed that the deiodination rate was linearly correlated with the loading of AgSAs, and hence AgSAs were the true catalytic centers for the 1e?-reduction of the C-I moieties. The oxidation state of AgSAs kept 0 in both the resting and the working states. A “work-in-tandem” mechanism involving AgSAs as the catalytic centers and AgNPs as the light absorber to achieve the borylation of aryl iodides under visible light irradiation is proposed. The current approach not only provides an alternative system for borylation and sulfenylation of aryl iodides, but also reveals a new activity of silver(I) salts involving AgSAs under visible light irradiation.
- Cui, Enxin,Guo, Lirong,Li, Haibin,Qiao, Dan,Tung, Chen-Ho,Wang, Yifeng
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p. 255 - 263
(2021/09/06)
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- Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides
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Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 to +1.79 V vs SCE. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN?-*, which can be used to activate reductively recalcitrant aryl chlorides (Ered ≈ -1.9 to -2.9 V vs SCE) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes.
- Cao, Jilei,Tang, Xinxin,Toh, Ren Wei,Wang, Han,Wu, Jie,Wu, Xiangyang,Xu, Jinhui,Yang, Xiaona,Yeow, Edwin K. L.,Zhou, Rong
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supporting information
p. 13266 - 13273
(2021/09/07)
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- Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
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Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
- Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
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supporting information
p. 5022 - 5037
(2021/05/04)
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- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
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In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
- Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
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supporting information
p. 15396 - 15405
(2021/10/12)
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- Undirected ortho-selectivity in C–H borylation of arenes catalyzed by NHC platinum(0) complexes
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Borylation of arenes with bis(pinacolato)diboron catalyzed by sterically encumbered NHC platinum complexes proceeds predominantly at ortho-position even in the absence of a directing group (o: m: p ratio up to 10: 3: 1). The similar borylation with pinacolborane would proceed less selectively.
- Rzhevskiy, Sergey A.,Topchiy, Maxim A.,Golenko, Yulia D.,Gribanov, Pavel S.,Sterligov, Grigorii K.,Kirilenko, Nikita Yu.,Ageshina, Alexandra A.,Bermeshev, Maxim V.,Nechaev, Mikhail S.,Asachenko, Andrey F.
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p. 569 - 571
(2020/10/09)
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- Direct C?H Borylation of Arenes Catalyzed by Saturated Hydride-Boryl-Iridium-POP Complexes: Kinetic Analysis of the Elemental Steps
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The saturated trihydride IrH3{κ3-P,O,P-[xant(PiPr2)2]} (1; xant(PiPr2)2=9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates the B?H bond of two molecules of pinacolborane (HBpin) to give H2, the hydride-boryl derivatives IrH2(Bpin){κ3-P,O,P-[xant(PiPr2)2]} (2) and IrH(Bpin)2{κ3-P,O,P-[xant(PiPr2)2]} (3) in a sequential manner. Complex 3 activates a C?H bond of two molecules of benzene to form PhBpin and regenerates 2 and 1, also in a sequential manner. Thus, complexes 1, 2, and 3 define two cycles for the catalytic direct C?H borylation of arenes with HBpin, which have dihydride 2 as a common intermediate. C?H bond activation of the arenes is the rate-determining step of both cycles, as the C?H oxidative addition to 3 is faster than to 2. The results from a kinetic study of the reactions of 1 and 2 with HBpin support a cooperative function of the hydride ligands in the B?H bond activation. The addition of the boron atom of the borane to a hydride facilitates the coordination of the B?H bond through the formation of κ1- and κ2-dihydrideborate intermediates.
- Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
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supporting information
p. 12632 - 12644
(2020/09/09)
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- Mechanistic Insights into C-H Borylation of Arenes with Organoiridium Catalysts Embedded in a Microporous Metal-Organic Framework
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Organometallic iridium catalysts can be used in conjunction with bispinacolatodiboron (B2Pin2) to effect the borylation of a variety of substrates such as arenes, alkanes, heteroarenes, and oxygenates. Recently, efforts have also focused on integrating these catalysts into porous supports, such as metal-organic frameworks (MOFs). While the mechanism of homogeneous borylation systems has been thoroughly investigated experimentally and computationally, analogous studies in MOF-supported iridium catalysts have not been conducted. Herein, we report the mechanistic investigation of a phenanthroline-iridium catalyst immobilized in the organic linker of Universitetet i Oslo (UiO)-67 (Zr6O4(OH)4(BPDC)4(PhenDC)2, BPDC = biphenyl-4,4′-dicarboxylate, PhenDC = 1,10-phenanthroline-4,4′-dicarboxylate). By using benzene as a model substrate, variable time normalization analysis (VTNA) of the kinetic data suggested a rate law consistent with zero-order in B2Pin2, and first-order in arene. A primary kinetic isotope effect (KIE) in the time course of benzene-d6 borylation also provided complementary information about the role of the arene in the rate-determining step of the reaction. Characterization by techniques such as X-ray absorption spectroscopy (XAS) confirmed the presence of Ir(III), while pair distribution function (PDF) analysis suggested structures containing an Ir-Cl bond, further substantiated by X-ray photoelectron spectroscopy (XPS). Analysis of postcatalysis materials by inductively coupled plasma-optical emission spectroscopy (ICP-OES) revealed low boron accumulation, which may indicate an absence of boron in the resting state of the catalyst. Finally, in comparing borylation of benzene and toluene, a slight selectivity for benzene is observed, which is similar to the analogous homogeneous reaction, indicating the influence of substrate sterics on reactivity.
- Chapman, Karena W.,Chen, Zhihengyu,Delferro, Massimiliano,Farha, Omar K.,Goetjen, Timothy A.,Idrees, Karam B.,Kaphan, David M.,Syed, Zoha H.,Wegener, Evan C.,Zhang, Xuan
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supporting information
(2020/04/15)
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- Metal-organic frameworks containing nitrogen-donor ligands for efficient catalytic organic transformations
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Metal-organic framework (MOFs) compositions based on nitrogen donor-based organic bridging ligands, including ligands based on 1,3-diketimine (NacNac), bipyridines and salicylaldimine, were synthesized and then post-synthetically metalated with metal precursors, such as complexes of first row transition metals. Metal complexes of the organic bridging ligands could also be directly incorporated into the MOFs. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
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Page/Page column 28; 31-33; 51-53; 86-88
(2020/06/03)
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- Single-Site Cobalt-Catalyst Ligated with Pyridylimine-Functionalized Metal-Organic Frameworks for Arene and Benzylic Borylation
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We report a highly active single-site heterogeneous cobalt-catalyst based on a porous and robust pyridylimine-functionalized metal-organic frameworks (pyrim-MOF) for chemoselective borylation of arene and benzylic C-H bonds. The pyrim-MOF having UiO-68 topology, constructed from zirconium-cluster secondary building units and pyridylimine-functionalized dicarboxylate bridging linkers, was metalated with CoCl2 followed by treatment of NaEt3BH to give the cobalt-functionalized MOF-catalyst (pyrim-MOF-Co). Pyrim-MOF-Co has a broad substrate scope, allowing the C-H borylation of halogen-, alkoxy-, alkyl-substituted arenes as well as heterocyclic ring systems using B2pin2 or HBpin (pin = pinacolate) as the borylating agent to afford the corresponding arene- or alkyl-boronate esters in good yields. Pyrim-MOF-Co gave a turnover number (TON) of up to 2500 and could be recycled and reused at least 9 times. Pyrim-MOF-Co was also significantly more robust and active than its homogeneous control, highlighting the beneficial effect of active-site isolation within the MOF framework that prevents intermolecular decomposition. The experimental and computational studies suggested (pyrim?-)CoI(THF) as the active catalytic species within the MOF, which undergoes a mechanistic pathway of oxidative addition, turnover limiting σ-bond metathesis, followed by reductive elimination to afford the boronate ester.
- Akhtar, Naved,Antil, Neha,Balendra,Begum, Wahida,Kumar, Ajay,Manna, Kuntal,Newar, Rajashree,Shukla, Sakshi
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supporting information
p. 10473 - 10481
(2020/08/05)
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- Controllable factors of supported IR complex catalysis for aromatic C?H borylation
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We have developed a catalyst in which an Ir complex and organic functionalities are coimmobilized on the silica surface. The catalytic activity for aromatic C?H borylation was significantly affected by (i) the linker length of the Ir?bipyridine complex, (ii) the coimmobilized organic functionality, and (iii) the substituents on the aromatic substrate compounds. The fine-tuned supported catalyst showed higher activity than the homogeneous Ir?bipyridine complex when using a specific substrate such as benzonitrile. We elucidated this property by conducting solid-state NMR, FT-IR, XAFS, and in situ FT-IR analysis.
- Chun, Wang-Jae,Maeda, Kyogo,Manaka, Yuichi,Motokura, Ken,Nakajima, Kiyotaka,Satter, Shazia Sharmin,Uemura, Yohei
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p. 14552 - 14559
(2020/12/21)
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- Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
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A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
- Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
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supporting information
p. 18231 - 18242
(2020/11/02)
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- Synthesis and structures of anionic rhenium polyhydride complexes of boron-hydride ligands and their application in catalysis
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The rhenium complex, [K(DME)(18-c-6)][ReH4(Bpin)(η2-HBpin)(κ2-H2Bpin)] 1, comprising hydride and boron ligands only, has been synthesized by exhaustive deoxygenation of the commercially available perrhenate anion (ReO4-) with pinacol borane (HBpin). The structure of 1 was analysed by X-ray crystallography, NMR spectroscopy, and DFT calculations. While no hydrides were located in the X-ray crystal structure, it revealed a trigonal arrangement of pinacol boron ligands. Variable-temperature NMR spectroscopy supported the presence of seven hydride ligands but further insight was hindered by the fluxionality of both hydride and boron ligands at low temperature. Further evaluation of the structure by Ab Initio Random Structure Searching (AIRSS) identified the presence of hydride, boryl, σ-borane, and dihydroborate ligands. This complex, either isolated or prepared in situ, is a catalyst for the 1,4-hydroboration of N-heteroaromatic substrates under simple operating procedures. It also acts as a reagent for the stoichiometric C-H borylation of toluene, displaying high meta regioselectivity in the borylated products. Reaction of 1 with 9-BBN resulted in HBpin substitution to form the new anionic tetra(dihydroborate) complex [K(DME)(18-c-6)][Re(κ2-H-9-BBN)4] 4 for which the hydride positions were clearly identified by X-ray crystallography. The method used to generate these isolable yet reactive boron-hydride complexes is direct and straightforward and has potential utility for the exploitation of other metal oxo compounds in operationally simple catalytic reactions.
- Donnelly, Liam J.,Love, Jason B.,Morrison, Carole A.,Parsons, Simon,Thomas, Stephen P.
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p. 9994 - 9999
(2020/10/06)
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- Transformations of Aryl Ketones via Ligand-Promoted C?C Bond Activation
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The coupling of aromatic electrophiles (aryl halides, aryl ethers, aryl acids, aryl nitriles etc.) with nucleophiles is a core methodology for the synthesis of aryl compounds. Transformations of aryl ketones in an analogous manner via carbon–carbon bond activation could greatly expand the toolbox for the synthesis of aryl compounds due to the abundance of aryl ketones. An exploratory study of this approach is typically based on carbon–carbon cleavage triggered by ring-strain release and chelation assistance, and the products are also limited to a specific structural motif. Here we report a ligand-promoted β-carbon elimination strategy to activate the carbon–carbon bonds, which results in a range of transformations of aryl ketones, leading to useful aryl borates, and also to biaryls, aryl nitriles, and aryl alkenes. The use of a pyridine-oxazoline ligand is crucial for this catalytic transformation. A gram-scale borylation reaction of an aryl ketone via a simple one-pot operation is reported. The potential utility of this strategy is also demonstrated by the late-stage diversification of drug molecules probenecid, adapalene, and desoxyestrone, the fragrance tonalid as well as the natural product apocynin.
- Dai, Hui-Xiong,Li, Hanyuan,Li, Ling-Jun,Liu, Qi-Sheng,Ma, Biao,Wang, Mei-Ling,Wang, Xing,Wang, Zhen-Yu,Xu, Hui
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p. 14388 - 14393
(2020/07/06)
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- Visible Light-Induced Borylation of C-O, C-N, and C-X Bonds
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Boronic acids are centrally important functional motifs and synthetic precursors. Visible light-induced borylation may provide access to structurally diverse boronates, but a broadly efficient photocatalytic borylation method that can effect borylation of a wide range of substrates, including strong C-O bonds, remains elusive. Herein, we report a general, metal-free visible light-induced photocatalytic borylation platform that enables borylation of electron-rich derivatives of phenols and anilines, chloroarenes, as well as other haloarenes. The reaction exhibits excellent functional group tolerance, as demonstrated by the borylation of a range of structurally complex substrates. Remarkably, the reaction is catalyzed by phenothiazine, a simple organic photocatalyst with MW 200 that mediates the previously unachievable visible light-induced single electron reduction of phenol derivatives with reduction potentials as negative as approximately - 3 V versus SCE by a proton-coupled electron transfer mechanism. Mechanistic studies point to the crucial role of the photocatalyst-base interaction.
- Arman, Hadi D.,Dang, Hang. T.,Haug, Graham C.,He, Ru,Jin, Shengfei,Larionov, Oleg V.,Nguyen, Viet D.,Nguyen, Vu T.,Schanze, Kirk S.
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supporting information
(2020/02/04)
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- Borylation of Diazonium Salts by Highly Emissive and Crystalline Carbon Dots in Water
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Efficient borylation reaction of diazonium salts in water is realized for the first time by using easily prepared, highly emissive and crystalline carbon dots. Electron-donating and electron-withdrawing groups on diazonium salts were well tolerated with moderate to good conversion efficiency. Compared with widely used metal complexes, organic dyes and quantum dots, the approach presented herein uses carbon dots, which are nontoxic and possess good biological and medicinal compatibility and high reactivity. Therefore, this approach presents a new prospective use for carbon dots in green chemistry.
- Lei, Tao,Wei, Si-Meng,Feng, Ke,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
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p. 1715 - 1719
(2020/03/23)
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- Photocatalytic C–X borylation of aryl halides by hierarchical SiC nanowire-supported Pd nanoparticles
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Hierarchical SiC nanowire-supported Pd nanoparticles showed high photocatalytic activity for the C-X (X = Br, I) borylation of aryl halides at 30 °C. The SiC/Pd Mott-Schottky contact enhances the rapid transfer of the photogenerated electrons from SiC to the Pd nanoparticles. As a result, the concentrated energetic electrons in the Pd nanoparticles can facilitate the cleavage of C-I or C-Br bonds, which normally requires high-temperature thermal processes. We show that the present Pd/SiC photocatalyst is capable of catalyzing the transformation of a large variety of aryl halides to their corresponding boronate esters under visible light irradiation, with excellent yields.
- Jiao, Zhi-Feng,Zhao, Ji-Xiao,Guo, Xiao-Ning,Guo, Xiang-Yun
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p. 357 - 363
(2019/12/28)
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- Nickel-Catalyzed C(sp2)-H Borylation of Arenes
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In this study, C(sp2)-H borylation of arenes was accomplished by a nickel catalyst, resulting in good yield. Alkyl and alkoxy arenes were successfully functionalized, affording C(sp2)-H borylated compounds. It was unraveled that the well-defined abnormal N-heterocyclic carbene based Ni(II) complex breaks into Ni nanoparticles (Ni-NPs), which act as catalytically active species. A series of controlled reactions under stoichiometric conditions along with spectroscopic studies and single-crystal X-ray crystallographic study helped us to understand the formation of Ni-NPs along with formation of a boron(III) compound during this reaction.
- Das, Arpan,Hota, Pradip Kumar,Mandal, Swadhin K.
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- A mesoporous NNN-pincer-based metal-organic framework scaffold for the preparation of noble-metal-free catalysts
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Through topology-guided synthesis, a Zr-based mesoporous MOF was successfully constructed, adopting a β-cristobalite-type structure. The MOF is embedded with well-arranged terpyridine coordination sites for facile post-synthetic metalation, and can be effectively used as a general scaffold for the preparation of noble-metal-free catalysts. For instance, the scaffolded metal@MOF material exhibits highly efficient catalytic activity for alkene epoxidation and arene borylation.
- Zhang, Yingmu,Li, Jialuo,Yang, Xinyu,Zhang, Peng,Pang, Jiandong,Li, Bao,Zhou, Hong-Cai
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p. 2023 - 2026
(2019/02/19)
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- Catalytic C?H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand
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Catalytic C?H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp3 C?H borylation of anisole derivatives were also presented.
- Kato, Takeru,Kuriyama, Shogo,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 2097 - 2101
(2019/05/28)
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- Expanding the Variety of Zirconium-based Inorganic Building Units for Metal–Organic Frameworks
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Two new zirconium-based metal–organic frameworks with the composition [Zr6O4(OH)4(OAc)6(BDC)3] (CAU-26) and [Zr5O4(OH)4(OAc)4(BDC)2] (CAU-27) are
- Leubner, Sebastian,Zhao, Haishuang,Van Velthoven, Niels,Henrion, Micka?l,Reinsch, Helge,De Vos, Dirk E.,Kolb, Ute,Stock, Norbert
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supporting information
p. 10995 - 11000
(2019/07/12)
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- Redox-Neutral Borylation of Aryl Sulfonium Salts via C-S Activation Enabled by Light
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Reported here is a novel photoinduced strategy for the borylation of aryl sulfonium salts using bis(pinacolato)diboron as the boron source. This method exploits redox-neutral aryl sulfoniums to gain access to aryl radicals via C-S bond activation upon photoexcitation under transition-metal-free conditions. Therefore, it grants access to diverse arylboronate esters with good performance from easily available aryl sulfoniums accompanied by mild conditions, operational simplicity, and easy scalability.
- Huang, Chen,Feng, Jie,Ma, Rui,Fang, Shuaishuai,Lu, Tao,Tang, Weifang,Du, Ding,Gao, Jian
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p. 9688 - 9692
(2019/12/02)
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- Cleavage of C(aryl)?CH3 Bonds in the Absence of Directing Groups under Transition Metal Free Conditions
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Organic chemists now can construct carbon–carbon σ-bonds selectively and sequentially, whereas methods for the selective cleavage of carbon–carbon σ-bonds, especially for unreactive hydrocarbons, remain limited. Activation by ring strain, directing groups, or in the presence of a carbonyl or a cyano group is usually required. In this work, by using a sequential strategy site-selective cleavage and borylation of C(aryl)?CH3 bonds has been developed under directing group free and transition metal free conditions. Methyl groups of various arenes are selectively cleaved and replaced by boryl groups. Mechanistic analysis suggests that it proceeds by a sequential intermolecular oxidation and coupling of a transient aryl radical, generated by radical decarboxylation, involving a pyridine-stabilized persistent boryl radical.
- Dai, Peng-Fei,Ning, Xiao-Shan,Wang, Hua,Cui, Xian-Chao,Liu, Jie,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 5392 - 5395
(2019/03/29)
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- Copper-Photocatalyzed Borylation of Organic Halides under Batch and Continuous-Flow Conditions
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The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested.
- Nitelet, Antoine,Thevenet, Damien,Schiavi, Bruno,Hardouin, Christophe,Fournier, Jean,Tamion, Rodolphe,Pannecoucke, Xavier,Jubault, Philippe,Poisson, Thomas
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supporting information
p. 3262 - 3266
(2019/02/13)
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- Electrochemical Radical Borylation of Aryl Iodides
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Herein, we report the first electrochemical strategy for the borylation of aryl iodides via a radical pathway using current as a driving force. A mild reaction condition allows an assorted range of readily available aryl iodides to be proficiently converted into synthetically valuable arylboronic esters under transition metal catalyst-free conditions. Moreover, this method also shows good functional group tolerance. Initial control mechanistic experiments reveal the formation of aryl radical as a key intermediate and the current plays an important role in the generation of radical intermediate.
- Hong, Junting,Liu, Qianyi,Li, Feng,Bai, Guangcan,Liu, Guoquan,Li, Man,Nayal, Onkar S.,Fu, Xuefeng,Mo, Fanyang
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supporting information
p. 347 - 351
(2019/03/07)
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- Visible-Light-Induced Organocatalytic Borylation of Aryl Chlorides
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The preparation of arylboronates from unactivated aryl chlorides in a transition-metal-free manner is rather challenging. There are only few examples to achieve this goal by using ultraviolet irradiation. Based on the mechanistic understanding of the diboron/methoxide/pyridine reaction system, we achieved photoactivation of the in situ generated super electron donor and developed a visible-light-induced organocatalytic method for efficient borylation of unactivated aryl chlorides.
- Zhang, Li,Jiao, Lei
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supporting information
p. 9124 - 9128
(2019/06/17)
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- Room temperature Pd(0)/Ad3P-catalyzed coupling reactions of aryl chlorides with bis(pinacolato)diboron
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Room temperature Pd(0)/Ad3P-catalyzed cross-coupling reactions of aryl chlorides with bis(pinacolato)diboron are described. The Pd(0)/Ad3P catalyst, generated from Ad3P-coordinated acetanilide-based palladacycle complex, proved to be an efficient catalyst system for the Miyaura borylation reactions of a variety of aryl chlorides with bis(pinacolato)diboron. The mild reaction condition, the easy availability of the catalyst and good coupling yields make these reactions potentially useful in organic synthesis.
- Dong, Jie,Guo, Hui,Peng, Wei,Hu, Qiao-Sheng
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supporting information
p. 760 - 763
(2019/02/16)
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- Copper-catalysed borylation of aryl chlorides
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We report herein the first Cu-catalysed borylation of a wide range of aryl chlorides with different electronic and steric properties using a readily prepared NHC-stabilised Cu catalyst and KOtBu as the base with B2pin2 (pin = pinacolato) as the boron reagent. The aryl chlorides are converted into their corresponding arylboronic esters in good yields. The new procedure shows broad functional group tolerance, and B2neop2 (neop = neopentyl glycolato) can also be applied as the boron reagent.
- Kuehn, Laura,Huang, Mingming,Radius, Udo,Marder, Todd B.
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supporting information
p. 6601 - 6606
(2019/07/16)
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- Pd(II) Complexes with Chelating Phosphinoferrocene Diaminocarbene Ligands: Synthesis, Characterization, and Catalytic Use in Pd-Catalyzed Borylation of Aryl Bromides
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We developed a novel, straightforward route toward Pd(II)-aminocarbene complexes bearing a P-chelating phosphinoferrocenyl substituent based on a three-component reaction of 1′-(diphenylphosphino)-1-isocyanoferrocene (1) with [PdCl2(cod)] (cod = cycloocta-1,5-diene) and nucleophilic amines. Depending on the type of the amine, the reaction produced acyclic diaminocarbenes and their saturated (imidazolin-2-ylidene) and unsaturated (imidazol-2-ylidene) cyclic counterparts (NHCs). Using (S)-2-(chloromethyl)pyrrolidine as the nucleophile, this method afforded a separable pair of stable diastereomeric bicyclic imidazolin-2-ylidene carbenes with different configurations of the planar-chiral ferrocene unit. The prepared P-chelating carbenes were characterized using spectroscopic methods, X-ray crystallography, and DFT methods. The last were used to explain the formation of isomeric open diaminocarbenes featuring NHR groups at the wing-tip position, trends in Pd-Cl bond lengths reflecting similar trans influences of the particular carbene and phosphine donors, and the results from cyclic voltammetric measurements. Furthermore, the carbenes were used as defined (pre)catalysts in Miyaura borylation of aryl bromides with bis(pinacolato)diboron. When applying the optimized catalytic system (1 mol % Pd catalyst, KOAc as the base, 2-propanol, 85 °C), this reaction produced a range of simple and substituted arylboronate pinacol esters in high yield and without biaryl side products.
- ?koch, Karel,Schulz, Ji?í,Císa?ová, Ivana,?těpni?ka, Petr
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p. 3060 - 3073
(2019/08/20)
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- Group 4 Post-Metallocenes Supported by [OCH2 N,C(σ-aryl)] Auxiliaries Bearing a Seven-Membered Metallacycle: Synthesis, Characterization, and Catalysts for Olefin Polymerization
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A series of pyridine-2-phenolate-6-(σ-aryl) [OCH2 N,C] group 4 bis(benzyl) precatalysts, featuring a flexible O,N-donor chelate, have been prepared and characterized by multinuclear NMR spectroscopy. These complexes adopt C1/su
- Liu, Cham-Chuen,Liu, Qian,Yiu, Shek-Man,Chan, Michael C. W.
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supporting information
p. 2963 - 2971
(2019/08/22)
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- Highly active, separable and recyclable bipyridine iridium catalysts for C-H borylation reactions
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Iridium complexes generated from Ir(i) precursors and PIB oligomer functionalized bpy ligands efficiently catalyzed the reactions of arenes with bis(pinacolato)diboron under mild conditions to produce a variety of arylboronate compounds. The activity of this PIB bound homogeneous catalyst is similar to that of an original non-recyclable catalyst which allows it to be used under milder conditions than other reported recyclable catalysts. This oligomer-supported Ir catalyst was successfully recovered through biphasic extraction and reused for eight cycles without a loss of activity. Biphasic separation after the initial use of the catalyst led to an insignificant amount of iridium leaching from the catalyst to the product, and no iridium leaching from the catalyst was observed in the subsequent recycling runs. Arylboronate products obtained after extraction are sufficiently pure as observed by 1H and 13C-NMR spectroscopy that they do not require further purification.
- Mamlouk, Hind,Suriboot, Jakkrit,Manyam, Praveen Kumar,Alyazidi, Ahmed,Bergbreiter, David E.,Madrahimov, Sherzod T.
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p. 124 - 127
(2018/01/17)
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- Metal-Free Radical Borylation of Alkyl and Aryl Iodides
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A metal-free radical borylation of alkyl and aryl iodides with bis(catecholato)diboron (B2cat2) as the boron source under mild conditions is introduced. The borylation reaction is operationally easy to conduct and shows high functional group tolerance and broad substrate scope. Radical clock experiments and density functional theory calculations provide insights into the mechanism and rate constants for C-radical borylation with B2cat2 are disclosed.
- Cheng, Ying,Mück-Lichtenfeld, Christian,Studer, Armido
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supporting information
p. 16832 - 16836
(2018/11/23)
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- LiHMDS-Promoted Palladium or Iron-Catalyzed ipso-Defluoroborylation of Aryl Fluorides
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A novel and efficient method for the synthesis of arylboronic acid pinacol esters via a palladium- or iron-catalyzed cross-coupling reaction of aryl fluorides with bis(pinacolato)diboron (B2pin2) in the presence of LiHMDS was developed. The Pd-catalyzed defluoroborylation of fluoroarenes is compatible with a variety of functional groups such as primary and secondary amine, ketone, trifluoromethyl, alkoxy, and boryl. Remarkably, no external ligand is required for enhanced conversion efficiency.
- Zhao, Xianghu,Wu, Mingsheng,Liu, Yisen,Cao, Song
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supporting information
p. 5564 - 5568
(2018/09/12)
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- METHODS OF MANUFACTURING OF BORON COMPOUND WITHOUT TRANSITION METALS
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The present invention refers to aryl boron compound number bath method relates to search, more particularly transition metal catalyst to a tank without the use of boron compounds number is given to the aryl organic halo [ceyn [ceyn] freight method are disclosed to boron. (by machine translation)
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Paragraph 0065; 0066; 0071; 0072; 0076
(2018/05/03)
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