- 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
- Ramadoss, Boobalan,Jin, Yushu,Asako, Sobi,Ilies, Laurean
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p. 658 - 663
(2022/02/21)
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- 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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- 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
-
supporting information
p. 64 - 68
(2021/12/27)
-
- 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
-
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
-
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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- Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C-O Bond Activation
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The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.
- Pein, Wesley L.,Wiensch, Eric M.,Montgomery, John
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supporting information
(2021/06/28)
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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
-
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.
-
supporting information
p. 3979 - 3985
(2021/02/03)
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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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- 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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- Iron-Catalyzed Borylation of Aryl Ethers via Cleavage of C-O Bonds
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Herein, we report the iron-catalyzed borylation of aryl ethers and aryl amines via cleavage of C-O and C-N bonds. This protocol does not require the use of Grignard reagents and displays a broad substrate scope, which allows the late-stage borylation. It also provides facile access to multisubstituted arenes through C-H functionalization using 2-pyridyloxy as the directing group.
- Zeng, Xiaoqin,Zhang, Yuxuan,Liu, Zhengli,Geng, Shasha,He, Yun,Feng, Zhang
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p. 2950 - 2955
(2020/04/15)
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- Iron-catalysed enantioconvergent Suzuki-Miyaura cross-coupling to afford enantioenriched 1,1-diarylalkanes
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The first stereoconvergent Suzuki-Miyaura cross-coupling reaction was developed to afford enantioenriched 1,1-diarylalkanes. An iron-based complex containing a chiral cyanobis(oxazoline) ligand framework was best to obtain enantioenriched 1,1-diarylalkanes from cross-coupling reactions between unactivated aryl boronic esters and benzylic chlorides. Enhanced yields were obtained when 1,3,5-trimethoxybenzene was used as an additive, which is hypothesized to extend the lifetime of the iron-based catalyst. Exceptional enantioselectivities were obtained with challenging ortho-substituted benzylic chlorides. This journal is
- Tyrol, Chet C.,Yone, Nang S.,Gallin, Connor F.,Byers, Jeffery A.
-
supporting information
p. 14661 - 14664
(2020/12/02)
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- Development and Mechanistic Studies of Iron-Catalyzed Construction of Csp2-B Bonds via C-O Bond Activation
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Herein we describe an iron-catalyzed borylation of alkenyl and aryl carbamates through the activation of a C-O bond. This protocol exhibits high efficiency, a broad substrate scope, and the late-stage borylation of biorelevant compounds, thus providing potential applications in medicinal chemistry. Moreover, this method enables orthogonal transformations of phenol derivatives and also offers good opportunities for the synthesis of multisubstituted arenes. Preliminary mechanistic studies suggest that a FeII/FeIII catalytic cycle via a radical pathway might be involved in the reaction.
- Geng, Shasha,Zhang, Juan,Chen, Shuo,Liu, Zhengli,Zeng, Xiaoqin,He, Yun,Feng, Zhang
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p. 5582 - 5588
(2020/07/08)
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- Boracene-based alkylborate enabled Ni/Ir hybrid catalysis
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Boracene-based alkylborate enabled visible light-mediated metallaphotoredox catalysis. The directly excited borate was easily oxidatively quenched by an excited Ir photoredox catalyst. Ni/Ir hybrid catalysis afforded the products under significantly low i
- Hosoya, Takamitsu,Miyamoto, Yusuke,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
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supporting information
p. 6598 - 6601
(2020/10/02)
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- Generation of Alkyl Radical through Direct Excitation of Boracene-Based Alkylborate
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The generation of tertiary, secondary, and primary alkyl radicals has been achieved by the direct visible-light excitation of a boracene-based alkylborate. This system is based on the photophysical properties of the organoboron molecule. The protocol is applicable to decyanoalkylation, Giese addition, and nickel-catalyzed carbon-carbon bond formations such as alkyl-aryl cross-coupling or vicinal alkylarylation of alkenes, enabling the introduction of various C(sp3) fragments to organic molecules.
- Hashizume, Daisuke,Hosoya, Takamitsu,Nakamura, Kei,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
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supporting information
p. 9938 - 9943
(2020/06/27)
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- Visible- And UV-Light-Induced Decarboxylative Radical Reactions of Benzoic Acids Using Organic Photoredox Catalysts
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Photoinduced decarboxylative radical reactions of benzoic acids with electron-deficient alkenes, diborane, and acetonitrile under organic photoredox catalysis conditions and mild heating afforded adducts, arylboronate esters, and the reduction product, respectively. The reaction is thought to involve single-electron transfer promoted the generation of aryl radicals via decarboxylation. A diverse range of benzoic acids were found to be suitable substrates for this photoreaction. Only our two-molecule organic photoredox system can work well for the direct photoinduced decarboxylation of benzoic acids.
- Kubosaki, Suzuka,Takeuchi, Haruka,Iwata, Yutaka,Tanaka, Yosuke,Osaka, Kazuyuki,Yamawaki, Mugen,Morita, Toshio,Yoshimi, Yasuharu
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p. 5362 - 5369
(2020/05/19)
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- Hydride Transfer Enables the Nickel-Catalyzed ipso-Borylation and Silylation of Aldehydes
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Nickel-catalyzed ipso-borylations and silylations of aldehydes are described for the first time. The new functional-group interconversion protocol is characterized by its scalability, functional-group tolerance and wide substrate scope, including examples of late-stage functionalization of complex molecules. The key for the successful reaction outcome is the use of a ketone as a hydride acceptor that intercepts the nickel hydride to undergo a reductive pathway, thus allowing formation of the desired C?B and C?Si bonds.
- Srimontree, Watchara,Guo, Lin,Rueping, Magnus
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supporting information
p. 423 - 427
(2019/12/27)
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- Para-selective borylation of monosubstituted benzenes using a transient mediator
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Herein, we conceptualized a transient mediator approach that has the capability of para-selective C-H functionalization of monosubstituted aromatics. This approach is enabled by in situ generation of a versatile sulfonium salt via highly electrophilic phenoxathiine or thianthrene dication intermediate which can be readily generated from its sulfoxide with trifluoromethanesulfonic anhydride. Preliminary mechanistic study implied that the remarkable para selectivity might be related to the incredible electrophilicity of thianthrene dication intermediate. The versatility of this approach was demonstrated via para-borylation of various monosubstituted simple aromatics combining the sulfonium salt formation with further photocatalyzed transformation.
- Wu, Jie,Wang, Zengwei,Chen, Xiao-Yue,Wu, Yichen,Wang, Daoming,Peng, Qian,Wang, Peng
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p. 336 - 340
(2019/12/09)
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- Pd-Catalyzed Site-Selective Borylation of Simple Arenes via Thianthrenation?
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Site-selective borylation of simple arenes was realized in one pot via an electrophilic thianthrenation/Pd-catalyzed borylation sequence. The key to achieve this operatically simple process is the use of Pd catalysis, which could tolerate the solvent and acidic conditions used in the thianthrenation step. This protocol features mild conditions, broad functional group tolerance, and simple manipulations, and is suitable for late-stage functionalization of a wide range of pharmaceuticals and complex bioactive molecules.
- Chen, Xiao-Yue,Huang, Yu-Hao,Zhou, Jian,Wang, Peng
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p. 1269 - 1272
(2020/08/13)
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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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- 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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- Method for preparing aryl boronate at room temperature
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The invention discloses a method for preparing aryl boronate represented by a formula I at a room temperature. The method comprises: carrying out a reaction on a diboron compound represented by a formula II and an aryl halide in an organic solvent for 0.5-8 h at a room temperature under the actions of an alkali, a chloro(2-dicyclohexylphosphino-2',4',6'-tri-isopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium (II) catalyst and a 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl ligand, and carrying out post-treatment to obtain the corresponding aryl boronate. According to the present invention, the method has characteristics of mild reaction conditions, simple operation, wide application range, good compatibility with various functional groups on aryl, high efficiency and economy, can achieve high yield of aryl borate under normal pressure and normal pressure conditions, and is suitable for large-scale preparation of aryl borate. The formulas I and II are defined in the specification, wherein R' represents any one selected from phenyl with substituent, pyridyl, thienyl, indyl, pyrazolyl and naphthyl.
- -
-
Paragraph 0020-0022; 0085-0087; 0093-0100
(2019/05/11)
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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
-
supporting information
p. 9124 - 9128
(2019/06/17)
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- Hydrogenation of (Hetero)aryl Boronate Esters with a Cyclic (Alkyl)(amino)carbene–Rhodium Complex: Direct Access to cis-Substituted Borylated Cycloalkanes and Saturated Heterocycles
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We herein report the hydrogenation of substituted aryl- and heteroaryl boronate esters for the selective synthesis of cis-substituted borylated cycloalkanes and saturated heterocycles. A cyclic (alkyl)(amino)carbene-ligated rhodium complex with two dimethyl groups at the ortho-alkyl scaffold of the carbene showed high reactivity in promoting the hydrogenation, thereby enabling the hydrogenation of (hetero)arenes with retention of the synthetically valuable boronate group. This process constitutes a clean, atom-economic, as well as chemo- and stereoselective route for the generation of cis-configured, diversely substituted borylated cycloalkanes and saturated heterocycles that are usually elusive and difficult to prepare.
- Ling, Liang,He, Yuan,Zhang, Xue,Luo, Meiming,Zeng, Xiaoming
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supporting information
p. 6554 - 6558
(2019/04/17)
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- Templated Synthesis of End-Functionalized Graphene Nanoribbons through Living Ring-Opening Alkyne Metathesis Polymerization
-
Atomically precise bottom-up synthesized graphene nanoribbons (GNRs) are promising candidates for next-generation electronic materials. The incorporation of these highly tunable semiconductors into complex device architectures requires the development of
- Von Kugelgen, Stephen,Piskun, Ilya,Griffin, James H.,Eckdahl, Christopher T.,Jarenwattananon, Nanette N.,Fischer, Felix R.
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supporting information
p. 11050 - 11058
(2019/08/07)
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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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- Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
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Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
- Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
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supporting information
p. 10514 - 10520
(2019/07/12)
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- BORON DIIODIDE COMPOUND, AND BORONIC ACID, BORONIC ESTER AND THE LIKE OBTAINED THEREFROM, AND PRODUCTION METHOD OF THEM
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PROBLEM TO BE SOLVED: To provide a method which enables simple production of a boronic acid, a boronic ester compound or the like suitable for production of various compounds. SOLUTION: The problem is solved by a boron diiodide compound represented by the following general formula (Y). (In the formula (Y), Ar is an n-valent heteroaryl ring, aryl ring having 10 or more carbon atoms, or substituted benzene ring, where at least one hydrogen atom in these rings may be substituted; n is an integer from 1 to 6; and at least one hydrogen atom in the compound represented by the formula (Y) may be substituted with deuterium.) COPYRIGHT: (C)2019,JPO&INPIT
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Paragraph 0254
(2019/05/10)
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- Cleavage of C(aryl)?CH3 Bonds in the Absence of Directing Groups under Transition Metal Free Conditions
-
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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- Photocatalyzed borylation using water-soluble quantum dots
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The synthesis of arylboronates by Sandmeyer-type reactions in the presence of water still remains a significant challenge. Herein, we report the use of water-soluble MPA-capped quantum dot (QD) photocatalysts for the borylation of diazonium salts in the presence of water. A biphasic system under mild acidic conditions remains critical to prevent decomposition and competitive disulphide bond formation. The present protocol offers a broader scope of substrates and borylating agents. Additionally, this catalytic system offers a significantly high turnover number (TON). The present methodology can effectively distinguish subtle reactivity differences between boronic acids and boronates. Mechanistic investigation suggests an excited-state electron transfer pathway.
- Chandrashekar, Hediyala B.,Maji, Arun,Halder, Ganga,Banerjee, Sucheta,Bhattacharyya, Sayan,Maiti, Debabrata
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supporting information
p. 6201 - 6204
(2019/06/07)
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- Redox reactions of small organic molecules using ball milling and piezoelectric materials
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Over the past decade, photoredox catalysis has harnessed light energy to accelerate bond-forming reactions. We postulated that a complementary method for the redox-activation of small organic molecules in response to applied mechanical energy could be dev
- Kubota, Koji,Pang, Yadong,Miura, Akira,Ito, Hajime
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p. 1500 - 1504
(2020/01/08)
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- Discovery, Optimization, and Target Identification of Novel Potent Broad-Spectrum Antiviral Inhibitors
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Viral infections are increasing and probably long-lasting global risks. In this study, a chemical library was exploited by phenotypic screening to discover new antiviral inhibitors. After optimizations from hit to lead, a novel potent small molecule (RYL-634) was identified, showing excellent broad-spectrum inhibition activity against various pathogenic viruses, including hepatitis C virus, dengue virus, Zika virus, chikungunya virus, enterovirus 71, human immunodeficiency virus, respiratory syncytial virus, and others. The mechanism of action and potential targets of RYL-634 were further explored by the combination of activity-based protein profiling and other techniques. Finally, human dihydroorotate dehydrogenase was validated as the major target of RYL-634. We did not observe any mutant resistance under our pressure selections with RYL-634, and it had a strong synergistic effect with some Food and Drug Administration-approved drugs. Hence, there is great potential for developing new broad-spectrum antivirals based on RYL-634.
- Yang, Yiqing,Cao, Lin,Gao, Hongying,Wu, Yue,Wang, Yaxin,Fang, Fang,Lan, Tianlong,Lou, Zhiyong,Rao, Yu
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p. 4056 - 4073
(2019/05/06)
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- Competing dehalogenation versus borylation of aryl iodides and bromides under transition-metal-free basic conditions
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In this work, selectivity-controllable base-promoted transition-metal-free borylation and dehalogenation of aryl halides are described. Under the conditions of borylation, the dehalogenation which emerges as a competitive side reaction has been well-controlled by carefully controlling the borylation conditions. On the other hand, the dehalogenation using benzaldehyde as a hydrogen source has also been accomplished. The applications of direct radical borylation and dehalogenation of aryl halides demonstrate their synthetic practicability in pharmaceutical-oriented organic synthesis. Based on the experimental evidences, the tBuOK/1,10-Phen-triggered radical nature of both competitive reactions has been revealed.
- Niu, Yi-Jie,Sui, Guo-Hui,Zheng, Hong-Xing,Shan, Xiang-Huan,Tie, Lin,Fu, Jia-Le,Qu, Jian-Ping,Kang, Yan-Biao
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p. 10805 - 10813
(2019/09/30)
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- Room-temperature borylation and one-pot two-step borylation/Suzuki-Miyaura cross-coupling reaction of aryl chlorides
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A highly efficient room-temperature borylation strategy of aryl chlorides is described. Utilizing Buchwald's second-generation preformed catalyst, boronate esters were obtained for a wide range of substrates in high yield. The method was also applied to Suzuki-Miyaura cross-coupling reaction in a one-pot two-step sequential manner, providing a facile and convenient access to the direct synthesis of biaryl compounds from aryl chlorides.
- Ji, Hong,Wu, Li-Yang,Cai, Jiang-Hong,Li, Guo-Rong,Gan, Na-Na,Wang, Zhao-Hua
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p. 13643 - 13648
(2018/04/24)
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- Additive- and Photocatalyst-Free Borylation of Arylazo Sulfones under Visible Light
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We developed a photocatalyst-free and additive-free, visible light induced borylation reaction using arylazo sulfones as starting material. This protocol shows some advantages such as mild conditions, simple equipment, and wide substrate scope, which gives a complementary protocol for the preparation of arylboronates.
- Xu, Yuliang,Yang, Xinying,Fang, Hao
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p. 12831 - 12837
(2018/10/20)
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- Metal-Free and Redox-Neutral Conversion of Organotrifluoroborates into Radicals Enabled by Visible Light
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Converting organoboron compounds into the corresponding radicals has broad synthetic applications in organic chemistry. To achieve these transformations, various strong oxidants such as Mn(OAc)3, AgNO3/K2S2O8, and Cu(OAc)2, in stoichiometric amounts are required, proceeding by a single-electron transfer mechanism. Established herein is a distinct strategy for generating both aryl and alkyl radicals from organotrifluoroborates through an SH2 process. This strategy is enabled by using water as the solvent, visible light as the energy input, and diacetyl as the promoter in the absence of any metal catalyst or redox reagent, thereby eliminating metal waste. To demonstrate its synthetic utility, an efficient acetylation to prepare valuable aryl (alkyl) methyl ketones is described and applications to construct C?C, C?I, C?Br, and C?S bonds are also feasible. Experimental evidence suggests that triplet diacetyl serves as the key intermediate in this process.
- Liu, Wenbo,Liu, Peng,Lv, Leiyang,Li, Chao-Jun
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supporting information
p. 13499 - 13503
(2018/09/25)
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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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- Pd II -Porphyrin Complexes - The First Use as Safer and Efficient Catalysts for Miyaura Borylation
-
We have developed a simple and convenient procedure for the preparation of pinacol arylboronates from aryl/heteroaryl bromides and bis(pinacolato)diborane using a Pd II -porphyrin complex as a catalyst. Seven different Pd II -porphyrin complexes (Pd II -T m HPP, Pd II -T m CPP, Pd II -TPP, Pd II -TST p SPP, Pd II -T p CPP, Pd II -T p TP, and Pd II -T p AP) have been synthesized and investigated for their catalytic influence in the Miyaura borylation.
- Rao, Kanusu Umamaheswara,Venkateswarlu, Katta
-
supporting information
p. 1055 - 1060
(2018/03/23)
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- Nickel-Catalyzed Decarbonylative Silylation, Borylation, and Amination of Arylamides via a Deamidative Reaction Pathway
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A nickel-catalyzed decarbonylative silylation, borylation, and amination of amides has been developed. This new methodology allows the direct interconversion of amides to arylsilanes, arylboronates, and arylamines and enables a facile route for carbon-heteroatom bond formations in a straightforward and mild fashion.
- Lee, Shao-Chi,Guo, Lin,Yue, Huifeng,Liao, Hsuan-Hung,Rueping, Magnus
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p. 2594 - 2598
(2017/10/31)
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- Convenient and General Zinc-Catalyzed Borylation of Aryl Diazonium Salts and Aryltriazenes under Mild Conditions
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A convenient and general zinc-catalyzed borylation of aryl diazonium salts and aryltriazenes has been developed. With bis- (pinacolato)diboron as the borylation reagent, aryldiazonium tetrafluoroborate salts and aryltriazenes were transformed into the corresponding arylboronates in moderate to excellent yields under mild conditions. As a convenient and practical methodology, no additional ligands, base, or any other additives are required here.
- Qi, Xinxin,Jiang, Li-Bing,Zhou, Chao,Peng, Jin-Bao,Wu, Xiao-Feng
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p. 345 - 349
(2017/06/23)
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- Borylation of aryldiazonium salts at room temperature in an aqueous solution under catalyst-free conditions
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A general and convenient borylation reaction of aryldiazonium tetrafluoroborate salts with B2pin2 has been developed. In this catalytic system, no catalyst, additional ligands or additives were required. The reaction proceeded smoothly in an aqueous solution, and a variety of arylboronates were isolated in moderate to excellent yields under mild reaction conditions.
- Qi, Xinxin,Li, Hao-Peng,Peng, Jin-Bao,Wu, Xiao-Feng
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supporting information
p. 3851 - 3853
(2017/09/15)
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- Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
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Despite the wide use of aryl radicals in organic synthesis, current methods to prepare them from aryl halides, carboxylic acids, boronic acids, and diazonium salts suffer from limitations. Aryl triflates, easily obtained from phenols, are promising aryl radical progenitors but remain elusive in this regard. Inspired by the single electron transfer process for aryl halides to access aryl radicals, we developed a simple and efficient protocol to convert aryl triflates to aryl radicals. Our success lies in exploiting sodium iodide as the soft electron donor assisted by light. This strategy enables the scalable synthesis of two types of important organic molecules, i.e., aryl boronates and aryl iodides, in good to high yields, with broad functional group compatibility in a transition-metal-free manner at room temperature. This protocol is anticipated to find potential applications in other aryl-radical-involved reactions by using aryl triflates as aryl radical precursors.
- Liu, Wenbo,Yang, Xiaobo,Gao, Yang,Li, Chao-Jun
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supporting information
p. 8621 - 8627
(2017/07/06)
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- Transition-Metal-Free, Visible-Light-Enabled Decarboxylative Borylation of Aryl N-Hydroxyphthalimide Esters
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Herein, we report a conceptually novel borylation reaction proceeding via a mild photoinduced decarboxylation of redox-activated aromatic carboxylic acids. This work constitutes the first application of cheap and easily prepared N-hydroxyphthalimide esters as aryl radical precursors and does not require the use of expensive transition metals or ligands. The reaction is operationally simple, scalable, and displays broad scope and functional group tolerance.
- Candish, Lisa,Teders, Michael,Glorius, Frank
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supporting information
p. 7440 - 7443
(2017/06/13)
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- Isonicotinate Ester Catalyzed Decarboxylative Borylation of (Hetero)Aryl and Alkenyl Carboxylic Acids through N-Hydroxyphthalimide Esters
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Decarboxylative borylation of aryl and alkenyl carboxylic acids with bis(pinacolato)diboron was achieved through N-hydroxyphthalimide esters using tert-butyl isonicotinate as a catalyst under base-free conditions. A variety of aryl carboxylic acids possessing different functional groups and electronic properties can be smoothly converted to aryl boronate esters, including those that are difficult to decarboxylate under transition-metal catalysis, offering a new method enabling use of carboxylic acid as building blocks in organic synthesis. Mechanistic analysis suggests the reaction proceeds through coupling of a transient aryl radical generated by radical decarboxylation with a pyridine-stabilized persistent boryl radical. Activation of redox active esters may proceed via an intramolecular single-electron-transfer (SET) process through a pyridine-diboron-phthalimide adduct and accounts for the base-free reaction conditions.
- Cheng, Wan-Min,Shang, Rui,Zhao, Bin,Xing, Wei-Long,Fu, Yao
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supporting information
p. 4291 - 4294
(2017/08/23)
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- Chemoselective coupling of 1,1-bis[(pinacolato)boryl]alkanes for the transition-metal-frec borylation of aryl and vinyl halides: A combined experimental and theoretical investigation
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A new transition-metal-frec borylation of aryl and vinyl halides using l,l-bis[(pinacolato)boryl]alkanes as boron sources is described. In this transformation one of the boron groups from 1,1-bis[(pinacolato)boryl]alkanes is selectively transferred to aryl and vinyl halides in the presence of sodium tert-butoxide as the only activator to form organoboronate esters. Under the developed borylation conditions, a broad range of organohalides are borylated with excellent chemo-selectivity and functional group compatibility, thus offering a rare example of a transition-metal-frec borylation protocol. Experimental and theoretical studies have becn performed to elucidate the reaction mechanism, revealing the unusual formation of Lewis acid/base adduct betwecn organohalides and α-borylcarbanion, generated in situ from the reaction of l,l-bis[(pinacolato)boryl]alkanes with an alkoxide base, to facilitate the borylation reactions.
- Lee, Yeosan,Baek, Seung-Yeol,Park, Jinyoung,Kim, Seoung-Tae,Tussupbayev, Samat,Kim, Jeongho,Baik, Mu-Hyun,Cho, Seung Hwan
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p. 975 - 984
(2017/05/16)
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- Highly Soluble p-Terphenyl and Fluorene Derivatives as Efficient Dopants in Plastic Scintillators for Sensitive Nuclear Material Detection
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Plastic scintillators are commonly used as first-line detectors for special nuclear materials. Current state-of-the-art plastic scintillators based on poly(vinyltoluene) (PVT) matrices containing high loadings (>15.0 wt %) of 2,5-diphenyloxazole (PPO) off
- Yemam, Henok A.,Mahl, Adam,Tinkham, Jonathan S.,Koubek, Joshua T.,Greife, Uwe,Sellinger, Alan
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supporting information
p. 8921 - 8931
(2017/07/11)
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- Nickel-Catalyzed Borylation of Aryl and Benzyl 2-Pyridyl Ethers: A Method for Converting a Robust ortho-Directing Group
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The nickel-catalyzed borylation of aryl 2-pyridyl ethers via the loss of a 2-pyridyloxy group is described. This method allows a 2-pyridyloxy group to be used as a convertible directing group in C?H bond functionalization reactions. The nickel catalyst can also borylate arylmethyl 2-pyridyl ethers, in which the stereochemistry at the benzylic position is retained in the case of chiral secondary benzylic substrates. (Figure presented.).
- Tobisu, Mamoru,Zhao, Jiangning,Kinuta, Hirotaka,Furukawa, Takayuki,Igarashi, Takuya,Chatani, Naoto
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supporting information
p. 2417 - 2421
(2016/08/16)
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- Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates
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A new and efficient nickel-catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)-diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional-group tolerance. Further experiments show that this protocol can be carried out on a gram scale and applied to orthogonal synthetic strategies.
- Guo, Lin,Rueping, Magnus
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supporting information
p. 16787 - 16790
(2016/11/17)
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- Energy Gap between the Poly-p-phenylene Bridge and Donor Groups Controls the Hole Delocalization in Donor-Bridge-Donor Wires
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Poly-p-phenylene wires are critically important as charge-transfer materials in photovoltaics. A comparative analysis of a series of poly-p-phenylene (RPPn) wires, capped with isoalkyl (iAPPn), alkoxy (ROPPn), and dialkylamino (R2NPPn) groups, shows unexpected evolution of oxidation potentials, i.e., decrease (-260 mV) for iAPPn, while increase for ROPPn (+100 mV) and R2NPPn (+350 mV) with increasing number of p-phenylenes. Moreover, redox/optical properties and DFT calculations of R2NPPn/R2NPPn+? further show that the symmetric bell-shaped hole distribution distorts and shifts toward one end of the molecule with only 4 p-phenylenes in R2NPPn+?, while shifting of the hole occurs with 6 and 8 p-phenylenes in ROPPn+? and iAPPn+?, respectively. Availability of accurate experimental data on highly electron-rich dialkylamino-capped R2NPPn together with ROPPn and iAPPn allowed us to demonstrate, using our recently developed Marcus-based multistate model (MSM), that an increase of oxidation potentials in R2NPPn arises due to an interplay between the electronic coupling (Hab) and energy difference between the end-capped groups and bridging phenylenes (Δ?). A comparison of the three series of RPPn with varied Δ? further demonstrates that decrease/increase/no change in oxidation energies of RPPn can be predicted based on the energy gap Δ? and coupling Hab, i.e., decrease if Δ? ab (i.e., iAPPn), increase if Δ? > Hab (i.e., R2NPPn), and minimal change if Δ? ≈ Hab (i.e., ROPPn). MSM also reproduces the switching of the nature of electronic transition in higher homologues of R2NPPn+? (n ≥ 4). These findings will aid in the development of improved models for charge-transfer dynamics in donor-bridge-acceptor systems.
- Wang, Denan,Talipov, Marat R.,Ivanov, Maxim V.,Rathore, Rajendra
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supporting information
p. 16337 - 16344
(2016/12/27)
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- Para -C-H borylation of benzene derivatives by a bulky iridium catalyst
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A highly para-selective aromatic C-H borylation has been accomplished. By a new iridium catalyst bearing a bulky diphosphine ligand, Xyl-MeO-BIPHEP, the C-H borylation of monosubstituted benzenes can be affected with para-selectivity up to 91%. This catalytic system is quite different from the usual iridium catalysts that cannot distinguish meta- and para-C-H bonds of monosubstituted benzene derivatives, resulting in the preferred formation of meta-products. The para-selectivity increases with increasing bulkiness of the substituent on the arene, indicating that the regioselectivity of the present reaction is primarily controlled by steric repulsion between substrate and catalyst. Caramiphen, an anticholinergic drug used in the treatment of Parkinsons disease, was converted into five derivatives via our para-selective borylation. The present [Ir(cod)OH]2/Xyl-MeO-BIPHEP catalyst represents a unique, sterically controlled, para-selective, aromatic C-H borylation system that should find use in streamlined, predictable chemical synthesis and in the rapid discovery and optimization of pharmaceuticals and materials.
- Saito, Yutaro,Segawa, Yasutomo,Itami, Kenichiro
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supporting information
p. 5193 - 5198
(2015/05/05)
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- Single-crystal-to-single-crystal metalation of a metal-organic framework: A route toward structurally well-defined catalysts
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Metal-organic frameworks featuring ligands with open chelating groups are versatile platforms for the preparation of a diverse set of heterogeneous catalysts through postsynthetic metalation. The crystalline nature of these materials allows them to be characterized via X-ray diffraction, which provides valuable insight into the structure of the metal sites that facilitate catalysis. A highly porous and thermally robust zirconium-based metal-organic framework, Zr6O4(OH)4(bpydc)6 (bpydc2- = 2,2′-bipyridne-5,5′-dicarboxylate), bears open bipyridine sites that readily react with a variety of solution- and gas-phase metal sources to form the corresponding metalated frameworks. Remarkably, Zr6O4(OH)4(bpydc)6 undergoes a single-crystal-to-single-crystal transformation upon metalation that involves a change in space group from Fm3m to Pa3. This structural transformation leads to an ordering of the metalated linkers within the framework, allowing structural characterization of the resulting metal complexes. Furthermore, Zr6O4(OH)4(bpydc)6 yields an active heterogeneous catalyst for arene C-H borylation when metalated with [Ir(COD)2]BF4 (COD = 1,5-cyclooctadiene). These results highlight the unique potential of metal-organic frameworks as a class of heterogeneous catalysts that allow unparalleled structural characterization and control over their active sites.
- Gonzalez, Miguel I.,Bloch, Eric D.,Mason, Jarad A.,Teat, Simon J.,Long, Jeffrey R.
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supporting information
p. 2995 - 3005
(2015/03/30)
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