- Chiral-at-Metal Phosphorescent Square-Planar Pt(II)-Complexes from an Achiral Organometallic Ligand
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The synthesis and characterization of a new kind of cis- and trans-cyclometalated square-planar platinum(II) complexes is reported. Uncharged organometallic compounds carrying one or two of the CΔN-donor ligand LCN were prepared. Due
- Schulte, Thorben R.,Holstein, Julian J.,Krause, Lennard,Michel, Reent,Stalke, Dietmar,Sakuda, Eri,Umakoshi, Keisuke,Longhi, Giovanna,Abbate, Sergio,Clever, Guido H.
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- FLPNO Nitroxide Radical Formation by a 1,1-Carboboration Route
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The 1-trimethylsilylethynyl-2-diarylphosphanylethynylbenzene substrates 7a-7c, with the diarylphosphanyl groups = PPh2, P(o-tolyl)2, or P(mesityl)2, were reacted with the strong boron Lewis acid B(C6F5)3 at ambient conditions. The starting materials 7a and 7b, featuring rather small nucleophilic phosphanyl substituents, underwent selective 1,1-carboboration at the C-C-PAr2 moiety, forming rather unreactive unsaturated vicinal P/B Lewis pairs 8a and 8b that show a relatively strong internal P···B Lewis base/Lewis acid interaction. In contrast, the PMes2 system 7c reacted with B(C6F5)3 by a reaction sequence which was initiated by 1,1-carboboration and involved tandem C6F5 and mesityl group migration to yield the unsaturated annulated P/B Lewis pair 9, featuring an electron-withdrawing C6F5 group at phosphorus. Compound 9 underwent cooperative P/B addition to the nitrogen atom of nitric oxide to give the persistent FLPNO? nitroxide radical 12. Radical 12 was characterized by electron spin resonance spectroscopy and by X-ray diffraction. It showed typical nitroxide radical reactions.
- Liedtke, René,Eller, Christina,Daniliuc, Constantin G.,Williams, Kamille,Warren, Timothy H.,Tesch, Matthias,Studer, Armido,Kehr, Gerald,Erker, Gerhard
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- Palladium(ii) Catalysed Cascade Strategy for the Synthesis of Dibenzo[5,6:7,8]cycloocta[1,2-: b] indol-10-ols/-10(15 H)-ones: Easy Access to 1,3,5,7-Cyclooctatetraenes (COTs)
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An atom-economic Pd(ii)-catalysed cascade cyclisation of 2-(biphenylethynyl)anilines tethered to an aldehyde or cyano group leads to the formation of dibenzo[5,6:7,8]cycloocta[1,2-b]indol-10-ols 6 or dibenzo[5,6:7,8]cycloocta[1,2-b]indol-10(15H)-ones 8 with high yields (up to 95%). The reaction proceeds via amino-palladation of the alkyne followed by nucleophilic addition onto the aldehyde/cyano group. Treatment of 6 with p-TsOH·H2O smoothly provided cyclooctatetraene (COT) derivatives 7. This journal is
- De, Sukanya,Jash, Moumita,Chowdhury, Chinmay
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- Rearrangement of a Transient Gold Vinylidene into Gold Carbenes
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The gold acetylide complex 20 endowed with a biaryl backbone provides opportunities for a study on the formation and fate of gold vinylidenes. Although the formyl group in 20 is not sufficiently electrophilic to get attacked by the acetylide in proximity, its activation with TBSOTf (TBSOTf=tert-butyldimethylsilyl trifluoromethanesulfonate) at low temperature triggered instantaneous formation of a gold vinylidene (21). This metastable species evolved into the cationic gold carbene complex 22 bearing a phenanthrene unit and a hydroxyl group at the aurated center; the recorded data suggest that this product might be better viewed as an acylgold species protonated by triflic acid. The use of [Me3O?BF4] as the activating agent led to formation of the analogous Fischer-type carbene 24, whereas replacement of gold by the [CpRu(PPh3)2]+ fragment allowed the ruthenium vinylidene 27 to be isolated, which closely resembles the proposed gold intermediate 21. The starting gold complex 20, the derived products 22 and 24, as well as vinylidene 27 were characterized by X-ray diffraction.
- Debrouwer, Wouter,Fürstner, Alois
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- Palladium-Catalyzed Cascade Cyclization of Alkene-Tethered Aryl Halides with o-Bromobenzoic Acids: Access to Diverse Fused Indolo[2,1- A[isoquinolines
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A novel palladium-catalyzed cascade cyclization of alkene-tethered aryl halides with o-bromobenzoic acids is described, which provides an efficient avenue for building various fused hexacyclic scaffolds containing indolo[2,1-a]isoquinoline in moderate to excellent yield. The method enables the construction of three C-C bonds through an intramolecular carbopalladation, C-H activation, and a decarboxylation sequence. Furthermore, dihydrocyclohepta[de]naphthalene-fused indolo[2,1-a]isoquinolines can be synthesized in moderate yield by constructing a seven-membered ring.
- Yang, Xiumei,Lu, Haiyan,Zhu, Xiaoming,Zhou, Liwei,Deng, Guobo,Yang, Yuan,Liang, Yun
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- Improved stability of a metallic state in benzothienobenzothiophene-based molecular conductors: an effective increase of dimensionality with hydrogen bonds
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A dihydroxy-substituted benzothienobenzothiophene, BTBT(OH)2, was synthesized, and its charge-transfer (CT) salt, β-[BTBT(OH)2]2ClO4, was successfully obtained. Thanks to the introduced hydroxy groups, a hydrogen-bonded chain structure connecting the BTBT molecules and counter anions was formed in the CT salt, which effectively increases the dimensionality of the electronic structure and consequently leads to a stable metallic state.
- Higashino, Toshiki,Ueda, Akira,Yoshida, Junya,Mori, Hatsumi
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- An on-surface Diels–Alder reaction
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The Diels–Alder reaction is one of the most popular reactions in organic chemistry. However, its use in the field of on-surface synthesis is hampered by the spatial restrictions of this cycloaddition reaction. Herein we selected a cyclic strained triyne t
- Albrecht, Florian,Castro-Esteban, Jesús,Fatayer, Shadi,Gross, Leo,Pérez, Dolores,Pe?a, Diego
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supporting information
p. 26346 - 26350
(2021/11/13)
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- Alumina-Mediated π-Activation of Alkynes
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The ability to induce powerful atom-economic transformation of alkynes is the key feature of carbophilic π-Lewis acids such as gold- and platinum-based catalysts. The unique catalytic activity of these compounds in electrophilic activations of alkynes is explained through relativistic effects, enabling efficient orbital overlapping with π-systems. For this reason, it is believed that noble metals are indispensable components in the catalysis of such reactions. In this study, we report that thermally activated γ-Al2O3activates enynes, diynes, and arene-ynes in a manner enabling reactions that were typically assigned to the softest π-Lewis acids, while some were known to be triggered exclusively by gold catalysts. We demonstrate the scope of these transformations and suggest a qualitative explanation of this phenomenon based on the Dewar-Chatt-Duncanson model confirmed by density functional theory calculations.
- Akhmetov, Vladimir,Amsharov, Konstantin,Feofanov, Mikhail,Sharapa, Dmitry I.
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supporting information
p. 15420 - 15426
(2021/09/30)
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- Copper-Catalyzed Chemoselective Silylative Cyclization of 2,2′-Diethynylbiaryl Derivatives
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In this protocol, copper-catalyzed diverse silylative carbocyclization reactions of 2,2′-diethynylbiaryl derivatives with silaboronate were reported. Three new and novel types of domino reactions for the copper-catalyzed transformation of silaboronate were discovered. The corresponding cyclobuta[l]phenanthrene, bis((silyl)methyl)phenanthrene, and silyl-substituted exocyclic diene products were chemoselectively formed with high efficiency.
- Zhao, Meng,Wang, Ying,Wang, Zi-Lu,Xu, Jian-Lin,Dai, Kai-Yang,Xu, Yun-He
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supporting information
p. 3859 - 3863
(2021/05/26)
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- Preparation of Structurally and Electronically Diverse N → B-Ladder Boranes by [2 + 2 + 2] Cycloaddition
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We report the synthesis of a series of eight N → B-ladder boranes through cobalt-mediated cyclotrimerization of (2-cyanophenyl)-dimesitylborane with different dialkynes. The resulting tetracoordinate boranes show variable electrochemical and optical prope
- Schepper, Jonas D. W.,Orthaber, Andreas,Pammer, Frank
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p. 14767 - 14776
(2021/10/25)
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- Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
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A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
- Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
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supporting information
p. 3981 - 3985
(2021/05/26)
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- Silver-Free Au(I) Catalysis Enabled by Bifunctional Urea- and Squaramide-Phosphine Ligands via H-Bonding
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A library of gold(I) chloride complexes with phosphine ligands incorporating pendant (thio)urea and squaramide H-bond donors was prepared with the aim of promoting chloride abstraction from Au(I) via H-bonding. In the absence of silver additives, complexes bearing squaramides and trifluoromethylated aromatic ureas displayed good catalytic activity in the cyclization of N-propargyl benzamides, as well as in a 1,6-enyne cycloisomerization, a tandem cyclization-indole addition reaction and the hydrohydrazination of phenylacetylene. Kinetic studies and DFT calculations indicate that the energetic span of the reaction is accounted by both the chloride abstraction step, facilitated by the bidentate H-bond donor via an associative mechanism, and the subsequent cyclization step.
- Echavarren, Antonio M.,Franchino, Allegra,Martí, àlex,Nejrotti, Stefano
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supporting information
p. 11989 - 11996
(2021/07/06)
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- Iodocyclisation of Electronically Resistant Alkynes: Synthesis of 2-Carboxy (and sulfoxy)-3-iodobenzo[ b ]thiophenes
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The iodocyclisation of alkynes bearing tethered nucleophiles is a highly effective method for the construction and diversification of heterocycles. A key limitation to this methodology is the 5-endo-dig iodocyclisation of alkynes that have an unfavourable electronic bias for electrophilic cyclisation. These tend to direct electrophilic attack of the iodonium atom to the wrong carbon for cyclisation, thus favouring competing addition reactions. Using our previously determined reaction conditions for the 5-endo-dig iodocyclisations of electronically resistant alkynes, we have achieved efficient synthetic access to 2-carboxy (and sulfoxy)-3-iodobenzo[b]thiophenes. The corresponding benzo[b]furans and indoles were not accessible under these conditions. This difference may arise due to the availability of a radical mechanism in the case of iodobenzo[b]thiophenes. The 2-carboxy functionality of the iodocyclised products can be further employed in iterative alkyne-coupling iodocyclisation reactions, where the carboxy group or an imine (Schiff base) partakes in a second iodocyclisation to generate a lactone or pyridine ring.
- Chen, Shuqi,Flynn, Bernard L.
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- Metal-Free Aminoiodination of Alkynes Under Visible Light Irradiation for the Construction of a Nitrogen-Containing Eight-Membered Ring System
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A method for the synthesis of dihydrodibenzo[c,e]azocine derivatives via a regioselective intramolecular aminoiodination of alkynes under visible light irradiation has been developed. This protocol uses a combination of iodine and hypervalent iodine to re
- Kanyiva, Kyalo Stephen,Marina, Tane,Nishibe, Shun,Shibata, Takanori
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supporting information
p. 2746 - 2751
(2021/04/05)
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- Synthesis, Characterization of Spirocyclic λ3-Iodanes and Their Application to Prepare 4,1-Benzoxazepine-2,5-diones and 1,3-Diynes
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Herein, a [3+2] cycloaddition of aza-oxyallylic cations with ethynylbenziodoxolones for synthesis of new λ3-iodanes containing spirocyclic 4-oxazolidinone has been developed. This cyclic λ3-iodanes display stability in air and excellent solubility in organic solvent. Using them as substrate, both the 4,1-benzoxazepine-2,5-diones and symmetrical 1,3-diynes derivatives were afforded in high yield under copper(I)-catalyzed conditions.
- Sun, Xu,Guo, Xiao-Qiang,Chen, Lian-Mei,Kang, Tai-Ran
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supporting information
p. 4312 - 4316
(2021/02/06)
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- The synthesis of cyclometalated platinum(ii) complexes with benzoaryl-pyridines as C^N ligands for investigating their photophysical, electrochemical and electroluminescent properties
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A series of (C^N)Pt(acac)-type complexes has been successfully synthesized with a benzo[b]furan, benzo[b]thiophene, benzo[b]selenophene, or benzo[b]tellurophene group in the benzoaryl-pyridine ligand. Using X-ray crystallography, the chemical structures o
- Wang, Dezhi,Chen, Xi,Yang, Hua,Zhong, Daokun,Liu, Boao,Yang, Xiaolong,Yue, Ling,Zhou, Guijiang,Ma, Miaofeng,Wu, Zhaoxin
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supporting information
p. 15633 - 15645
(2020/11/24)
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- Concise synthesis of phospholene and its P-stereogenic derivatives
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A simple method to build phospholene derivatives has been achieved in a one-pot reaction with readily available o-alkynylaryl bromides and alkylphosphine oxides. This method is also applicable to synthesize P-stereogenic phospholenes, and the resulting chiral phosphine was utilized as a ligand for coordination chemistry.
- Duan, Zheng,Hu, Wei,Li, Er-Qing,Mathey, Fran?ois
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p. 14772 - 14778
(2020/12/29)
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- Synthesis of Cycloheptatrienes, Oxepines, Thiepines, and Silepines: A Comparison between Br?nsted Acid and Au-Catalysis
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The cyclization of 1-(benzyl-, oxyaryl-, thioaryl-, and silaaryl)-2-ethynylbenzenes under Br?nsted acid- and Au(I)-catalysis is described. Br?nsted acid catalysis favors without exception the formation of the products derived from the regioselective proto
- Alcarazo, Manuel,Golz, Christopher,Sprenger, Kristin
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supporting information
p. 6245 - 6254
(2020/10/02)
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- B/N-Doped p-Arylenevinylene Chromophores: Synthesis, Properties, and Microcrystal Electron Crystallographic Study
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Linearly conjugated systems have long served as an archetype of conjugated materials, but suffer from two intrinsic structural problems: potential instability due to intermolecular interactions and the flexibility of the C-C bonds connecting C═C bonds. Ef
- Lu, Hua,Nakamuro, Takayuki,Yamashita, Keitaro,Yanagisawa, Haruaki,Nureki, Osamu,Kikkawa, Masahide,Gao, Han,Tian, Jiangwei,Shang, Rui,Nakamura, Eiichi
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p. 18990 - 18996
(2020/11/13)
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- Reversible Multicomponent and Gate Triggered by Stoichiometric Chemical Pulses Commands the Self-Assembly and Actuation of Catalytic Machinery
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The present work demonstrates the operation of a reversible supramolecular gate, i.e., an ensemble of various components linked by chemical communication, which is triggered by stoichiometric chemical inputs and by obeying the AND truth table delivers a s
- Biswas, Pronay Kumar,Saha, Suchismita,Gaikwad, Sudhakar,Schmittel, Michael
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supporting information
p. 7889 - 7897
(2020/05/25)
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- Chrysene-Based Blue Emitters
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Chrysene and its bisbenzannulated homologue, naphtho[2,3-c]tetraphene, were synthesized through a PtCl2-catalyzed cyclization of alkynes, which also furnished corresponding biaryls subsequent to a Glaser coupling reaction of the starting alkynes. The optoelectronic properties of 5,5′-bichrysenyl and 6,6′-binaphtho[2,3-c]tetraphene were compared to their chrysene-based “monomers”. Oxidative cyclodehydrogenations of bichrysenyl and its higher homologue towards large nanographenes were also investigated.
- Nathusius, Marvin,Ejlli, Barbara,Rominger, Frank,Freudenberg, Jan,Bunz, Uwe H. F.,Müllen, Klaus
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supporting information
p. 15089 - 15093
(2020/10/21)
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- Diisobutylaluminum Hydride Promoted Selectivity-Switchable Synthesis of Benzothiophene Oxides and Benzothiophenes via an Al-Li-Dimetalated Intermediate
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We developed an efficient and direct method for synthesis of benzothiophene oxides from 1-bromo-2-[2-(trimethylsilyl)ethynyl]benzenes and thionyl chloride as an easily accessible source of the sulfinyl group. Benzothiophenes were also synthesized selectiv
- Uchida, Seiya,Kinoshita, Hidenori,Miura, Katsukiyo
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supporting information
p. 3123 - 3127
(2020/04/10)
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- Synthesis of selenium-containing biindolyls and their Diels–Alder reaction toward the synthesis of heteroannulated [a]- and [c]-carbazoles
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We reported the first syntheses of 2- and 3-(2-(benzo[b]selenophen-2-yl)-indoles and their Diels–Alder reactions to furnish six unique annulated benzoselenphene carbazoles. This facile route can be used to synthesize selenium-containing biindolyl derivati
- Wang, Ruei-Yu,Kao, Wei-Ting,Shih, Tzenge-Lien
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p. 829 - 837
(2019/11/19)
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- Frustrated Lewis pair-catalyzed double hydroarylation of alkynes with: N -substituted pyrroles
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Metal-free hydroarylation of alkynes with N-substituted pyrroles is shown to be most efficiently mediated by B(C6F5)3 to yield 12 variants of dipyrrole-alkanes, a mono-hydroarylation product and a tetrahydroarylation produ
- Guo, Jing,Cheong, Odelia,Bamford, Karlee L.,Zhou, Jiliang,Stephan, Douglas W.
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supporting information
p. 1855 - 1858
(2020/02/22)
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- Visible-Light Mediated Hydrosilylative and Hydrophosphorylative Cyclizations of Enynes and Dienes
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Described herein is a visible-light mediated intermolecular radical cyclization approach to access heterocycles. Heteroatom radicals, such as silicon and phosphorus atom radicals, were generated via direct hydrogen atom abstraction by the photoexcited catalyst species with hydro-silanes and phosphine oxides. The radical addition/cyclization/HAT (hydrogen atom transfer) reaction sequences of 1,6-enynes and 1,6-dienes were highly efficient delivering the desired heterocycles in good yields.
- Chen, Xiaoyun,Hou, Hong,Shi, Yaocheng,Xu, Yue,Yan, Chaoguo,Yang, Haibo,Zhu, Shaoqun
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supporting information
(2020/03/04)
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- One-Pot Copper-Catalyzed Three-Component Reaction of Sulfonyl Azides, Alkynes, and Allylamines to Access 2,3-Dihydro-1 H-imi-dazo[1,2-a]indoles
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A copper-catalyzed multicomponent reaction of sulfonyl azides, alkynes, and allylamines affording 2,3-dihydro-1 H-imidazo-[1,2-a]indoles in moderate yields is reported. Four C-N bonds are constructed- by way of azide-alkyne cycloaddition (CuAAC) and double Ullmann-type coupling reactions in a one-pot process.
- Jin, Hongwei,Liu, Daohong,Liu, Yunkui,Zhou, Bingwei
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supporting information
p. 1417 - 1424
(2020/04/27)
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- Selective Synthesis of Phenanthrenes and Dihydrophenanthrenes via Gold-Catalyzed Cycloisomerization of Biphenyl Embedded Trienynes
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Readily available o′-alkenyl-o-alkynylbiaryls, a particular type of 1,7-enynes, undergo a selective cycloisomerization reaction in the presence of a gold(I) catalyst to give interesting phenanthrene and dihydrophenanthrene derivatives in high yields. The solvent used provokes a switch in the evolution of the gold intermediate and plays a key role in the reaction outcome.
- Milián, Ana,Garciá-Garciá, Patricia,Pérez-Redondo, Adrián,Sanz, Roberto,Vaquero, Juan J.,Fernández-Rodríguez, Manuel A.
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supporting information
p. 8464 - 8469
(2020/11/02)
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- γ-Carboline synthesis enabled by Rh(iii)-catalysed regioselective C-H annulation
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A redox-neutral Rh(iii)-catalyzed C-H annulation of indolyl oximes was developed. Relying on the use of various alkynyl silanes as the terminal alkyne surrogates, the reaction exhibited a reverse regioselectivity, thus giving an exclusive and easy way for the synthesis of a wide range of substituent free γ-carbolines at C3 position with high efficiency. Deuterium-labelling experiments and kinetic analysis have preliminarily shed light on the working mode of this catalytic system. This journal is
- Jiang, Bo,Jia, Jingwen,Sun, Yufei,Wang, Yichun,Zeng, Jing,Bu, Xiubin,Shi, Liangliang,Sun, Xiaoying,Yang, Xiaobo
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supporting information
p. 13389 - 13392
(2020/11/10)
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- Three-coordinate copper(II) alkynyl complex in C-C bond formation: The sesquicentennial of the glaser coupling
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Copper(II) alkynyl species are proposed as key intermediates in numerous Cu-catalyzed C-C coupling reactions. Supported by a β-diketiminate ligand, the three-coordinate copper(II) alkynyl [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3) forms upon reaction of the alkyne H-C≡CAr with the copper(II) tertbutoxide complex [CuII]-OtBu. In solution, this [CuII]-C≡CAr species cleanly transforms to the Glaser coupling product ArC≡C-C≡CAr and [CuI](solvent). Addition of nucleophiles R′C≡C-Li (R′ = aryl, silyl) and Ph-Li to [CuII]-C≡CAr affords the corresponding Csp-Csp and Csp-Csp2 coupled products RC≡C-C≡CAr and Ph-C≡CAr with concomitant generation of [CuI](solvent) and {[CuI]-C≡CAr}-, respectively. Supported by density functional theory (DFT) calculations, redox disproportionation forms [CuIII](C≡CAr)(R) species that reductively eliminate R-C≡CAr products. [CuII]-C≡CAr also captures the trityl radical Ph3C· to give Ph3C-C≡CAr. Radical capture represents the key Csp-Csp3 bond-forming step in the copper-catalyzed C-H functionalization of benzylic substrates R-H with alkynes H-C≡CR′ (R′ = (hetero)aryl, silyl) that provide Csp-Csp3 coupled products R-C≡CR via radical relay with tBuOOtBu as oxidant.
- Warren, Timothy H.,Bakhoda, Abolghasem,Okoromoba, Otome E.,Greene, Christine,Boroujeni, Mahdi Raghibi,Bertke, Jeffery A.
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supporting information
p. 18483 - 18490
(2020/11/27)
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- Br?nsted Acid-Catalyzed Enantioselective Cycloisomerization of Arylalkynes
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The first example of an enantioselective carbocyclization of an alkyne-containing substrate catalyzed by chiral Br?nsted acids was achieved. The use of the 2-hydroxynaphthyl substituent on the alkyne as a directing group constituted the key parameter enabling both efficient regioselective protonation of the carbon–carbon triple bond and chiral induction. The key cationic intermediate could be depicted either as a cationic vinylidene ortho-quinone methide or a stabilized vinyl cation. Atropoisomeric phenanthrenes derivatives were produced in high yields and good enantioselectivities under mild, metal-free reaction conditions in the presence of chiral N-triflylphosphoramide catalysts. The carbenic nature of the cationic intermediate was also exploited to describe an example of alkyne/alkane cycloisomerization.
- Abadie, Baptiste,Berlande, Murielle,Dhara, Kalyan,Gicquiaud, Julien,Hermange, Philippe,Sotiropoulos, Jean-Marc,Toullec, Patrick Y.
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supporting information
p. 16266 - 16271
(2020/11/30)
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- Expansion of the scope of alkylboryl-bridged N → B-ladder boranes: New substituents and alternative substrates
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A series of new boranes capable of forming intramolecular N → B-heterocycles has been prepared and their properties have been studied by electrochemical methods and UV-vis-spectroscopy complemented by DFT calculations. A dimethylborane (BMe2), haloborane derivatives (BBr2, BF2, BI2) and mixed cyano/isocyano-borane (B(CN)(NC)) have been prepared by different techniques. Furthermore, 2′-alkynyl-substituted 2-phenylpyridines bearing terminal tert-butyl- and trimethylsilyl-groups are introduced as a new class of substrates for hydroboration. Successful hydroboration with either 9H-borabicyclo[3.3.1]-nonane (9H-BBN), dimesitylborane (Mes2B-H), or Piers' borane ((C6F5)2B-H, BPF-H) furnished new π-extended boranes capable of forming intramolecular six- or seven-membered N → B-heterocycles (tBuBBN, SiBPF), and, in the case of Mes2BH, formation of a sterically crowded styrylborane (SiBMes2) incapable of intramolecular N → B-coordination was observed. All the boranes listed above except BMe2 have been structurally characterized, and a study of their electrochemical properties showed that the systematic variation of the substituents on boron allows for the incremental variation of the electron affinity of the phenylpyridine-model system over a total range of >0.7 eV between alkylboranes (BMe2, BBN) and B(CN)(NC). B(CN)(NC) shows the strongest N → B-bond (≈175 kJ mol-1), and highest electron-affinity observed so far, and is the first example of a borane bearing an isocyano-substituent on boron.
- Pammer, Frank,Schepper, Jonas,Gl?ckler, Johannes,Sun, Yu,Orthaber, Andreas
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p. 10298 - 10312
(2019/07/15)
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- Blue light-green light thermal delay fluorescent material based on rigid phosphine oxide group
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A blue light-green light thermal delay fluorescent material based on a rigid oxygen phosphine group has a structure shown as formula (I) as shown in the specification; the blue light-green light thermal active delay fluorescent (TADF) material based on the rigid oxygen phosphine group has very good color purity of blue light or green light, very high light emitting quantum efficiency and charge injection/transmission performance, and is suitable for being used as a luminescent material to prepare high-performance organic electroluminescent devicea; in addition, and the blue light material alsohas a very high excited state energy level, can be used as a main material for preparing the high-performance organic electroluminescent devices.
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Paragraph 0047; 0049-0050
(2019/07/01)
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- Benzo[b]tellurophenes as a potential histone H3 lysine 9 demethylase (KDM4) inhibitor
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Gene expression and tumor growth can be regulated by methylation levels of lysine residues on histones, which are controlled by histone lysine demethylases (KDMs). Series of benzo[b]tellurophene and benzo[b]selenophene compounds were designed and synthesi
- Choi, Yong-Sung,Jeong, Jin-Hyun,Kim, Yoon-Jung,Kwon, So Hee,Lee, Dong Hoon
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- Direct synthesis of dialkylarylvinylsilane derivatives: Metathesis of dialkylaryl-iso-propenylsilane and its application to tetracyclic silacycle dye synthesis
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The metathesis of dialkylarylvinylsilane, which has not been accomplished to date, is achieved using dialkylaryl-iso-propenylsilane as a substrate. In addition, we discovered that the reason why the metathesis of a ruthenium carbene complex and dialkylarylvinylsilane is difficult is the formation of a carbide complex.
- Yoshioka, Shohei,Takehara, Tsunayoshi,Matsuzaki, Tsuyoshi,Suzuki, Takeyuki,Tsujino, Hirofumi,Uno, Tadayuki,Tsutsumi, Yasuo,Murai, Kenichi,Fujioka, Hiromichi,Arisawa, Mitsuhiro
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supporting information
p. 14070 - 14073
(2019/11/25)
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- Dioxazolones as masked ester surrogates in the Pd(ii)-catalyzed direct C-H arylation of 6,5-fused heterocycles
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A simple and effective Pd(ii)-catalyzed regioselective C(2)-H arylation of 6,5-fused heterocycles with dioxazolones as a masked ester surrogate under mild conditions is reported. The significance of the arylation is highlighted by the new reactivity demonstrated in dioxazolones via proximal C-H activation of the cyclic carbonate of the hydroxamic acid functionality under protic conditions.
- Saxena, Paridhi,Maida, Neha,Kapur, Manmohan
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supporting information
p. 11187 - 11190
(2019/09/30)
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- Syntheses of substituted benzosiloles and siloles by diisobutylaluminium hydride-promoted cyclization of 1-silyl-2-(2-silylethynyl)benzenes and 1,4-disilylalk-3-en-1-ynes
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An efficient method for preparing substituted benzosiloles and unsymmetrically substituted siloles by intramolecular C-Si bond formation has been developed. The reaction of 1-methoxysilyl-2-[2-(trimethylsilyl)ethynyl]benzenes with 1.5 equiv of diisobutylaluminium hydride (DIBAL-H) gave benzosiloles in good to high yields. Similarly 4-methoxysilyl-1-silylalk-3-en-1-ynes were cyclized to multisubstituted siloles. Mechanistic study of this transformation uncovered that the methoxysilyl group was initially converted into the corresponding hydrosilyl group by the action of DIBAL-H, and that the resultant hydrosilanes underwent the DIBAL-H-promoted cyclization to benzosiloles. When 1-hydrosilyl-2-[2-(trimethylsilyl)ethynyl]benzenes were used as substrates, a substoichiometric amount of DIBAL-H was enough for the cyclization. The DIBAL-H-promoted transformation could be applied to regio-defined synthesis of unsymmetrically substituted siloles from 4-hydrosilyl-1-silylalk-3-en-1-ynes. This pre-installation approach provides a straightforward access to multisubstituted siloles with complete regioselection.
- Kinoshita, Hidenori,Fukumoto, Hiroki,Ueda, Akihiro,Miura, Katsukiyo
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p. 1632 - 1645
(2018/02/19)
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- Discovery of a Photoinduced Dark Catalytic Cycle Using in Situ LED-NMR Spectroscopy
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We report the use of LED-NMR spectroscopy to study the reaction mechanism of a newly discovered photoinduced iron-catalyzed cycloisomerization of alkynols to cyclic enol ethers. By understanding on/off ligand binding to the catalyst, we were able to appro
- Lehnherr, Dan,Ji, Yining,Neel, Andrew J.,Cohen, Ryan D.,Brunskill, Andrew P. J.,Yang, Junyu,Reibarkh, Mikhail
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supporting information
p. 13843 - 13853
(2018/10/24)
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- Efficient endo Cycloisomerization of Terminal Alkynols Catalyzed by a New Ruthenium Complex with 8-(Diphenylphosphino)quinoline Ligand and Mechanistic Investigation
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Several new ruthenium complexes supported by the P,N-donor ligand 8-(diphenylphosphino)quinoline (DPPQ) were synthesized, including [RuCl2(DPPQ)2] (1), [Ru(μ-Cl)(DPPQ)2]2(BPh4)2 (2), and [RuCl(DPPQ)2Py](BF4) (3). Complex 2, with only 1 mol % loading, was found to be catalytically active for the endo cycloisomerization of various terminal alkynols to endo-cyclic enol ethers in moderate to excellent yields. In particular, the 7- and 8-endo heterocyclization can be achieved efficiently to give the seven-membered 3-benzoxepine and eight-membered 3-benzo[d]oxocine derivatives. The stoichiometric reactions of 2 with various alkynol substrates have been carried out to investigate the mechanism, which led to a series of seven-, six-, and five-membered oxacyclocarbene ruthenium complexes including [RuCl(DPPQ)2{=CCH2C6H4CH2CH2O}](BPh4) (12) and [RuCl(DPPQ)2{=CCH2(CH2)nCH2O}](BPh4) (n=3, 12′; n=2, 13; n=1, 14). The quantitative transformation of oxacyclocarbene 12 into catalyst 2 and 3-benzoxepine 5 a as well as the efficient catalytic activity of 12 for the endo-cyclization of 2-(2-ethynylphenyl)ethanol (4 a) demonstrated that 12 is a key intermediate involved in the catalytic cycle. Moreover, comparative studies on the modeling reactions and catalytic activity of the series of oxacyclocarbene complexes indicated that the different catalytic activity of 2 for the endo-cycloisomerization of different types of alkynols can be related to the reactivity of the respective ruthenium oxacyclocarbene intermediates.
- Cai, Tao,Yang, Yu,Li, Wei-Wei,Qin, Wen-Bing,Wen, Ting-Bin
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supporting information
p. 1606 - 1618
(2018/01/11)
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- Palladium and Lewis-Acid-Catalyzed Intramolecular Aminocyanation of Alkenes: Scope, Mechanism, and Stereoselective Alkene Difunctionalizations
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An expansion of methodologies aimed at the formation of versatile organonitriles, via the intramolecular aminocyanation of unactivated alkenes, is herein reported. Importantly, the need for a rigid tether in these reactions has been obviated. The ease-of-synthesis and viability of substrates bearing flexible backbones has permitted for diastereoselective variants as well. We demonstrated the utility of this methodology with the formation of pyrrolidones, piperidinones, isoindolinones, and sultams. Furthermore, subsequent transformation of these motifs into medicinally relevant molecules is also demonstrated. A double crossover 13C-labeling experiment is consistent with a fully intramolecular cyclization mechanism. Deuterium labeling experiments support a mechanism involving syn-addition across the alkene.
- Pan, Zhongda,Wang, Shengyang,Brethorst, Jason T.,Douglas, Christopher J.
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supporting information
p. 3331 - 3338
(2018/03/13)
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- Rh(III)-Catalyzed Phosphine Oxide Migration Reactions: Selective Synthesis of 3-Phosphinoylindoles
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3-Phosphinoylindoles are important components of biological active natural products and materials in pharmaceuticals. Herein, a new approach for the synthesis of 3-phosphinoylindoles has been established by a Rh(III)-catalyzed cyclization from readily acc
- Wang, Chun-Hai,Yang, Shang-Dong
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supporting information
p. 2401 - 2404
(2018/09/10)
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- COMPOUND FOR ORGANIC OPTOELECTRONIC DEVICE, ORGANIC OPTOELECTRONIC DEVICE AND DISPLAY APPARATUS
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The present invention relates to a compound for an organic optoelectronic device represented by chemical formula 1, an organic optoelectronic device employing the same and a display device apparatus. The details of chemical formula 1 are as defined in the specification.
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Paragraph 0238
(2018/12/11)
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- Dual Gold-Catalyzed Three-Component Reaction: Efficient Synthesis of Indene-Fused Esters, Acids, and Lactones through Gold Vinylidene Intermediates
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A dual gold(I)-catalyzed three-component reaction was developed to prepare indene-fused carboxylic acid derivatives from diynes, alcohols, and pyridine N-oxides in both inter- and intramolecular fashions. The pyridine N-oxides were found to exhibit distinct selectivity unlike the α-oxo gold carbene intermediates in the well-developed gold-catalyzed oxidative functionalization of alkynes. Experimental studies and DFT calculations support double nucleophilic substitution of a gold vinylidene intermediate.
- Yu, Congjun,Ma, Xiaodong,Chen, Bin,Tang, Bencan,Paton, Robert S.,Zhang, Guozhu
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supporting information
p. 1561 - 1565
(2017/04/01)
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- Intramolecular addition of benzyl anion to alkyne utilizing [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis
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A novel reaction system for intramolecular addition of benzyl anions to alkynes was developed by utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The present reaction is a rare example of a catalytic addition reaction of an unstabilized benzyl anion under Br?nsted base catalysis.
- Kondoh, Azusa,Ozawa, Ryosuke,Aoki, Takuma,Terada, Masahiro
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supporting information
p. 7277 - 7281
(2017/09/25)
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- Zirconacyclopentadiene-Annulated Polycyclic Aromatic Hydrocarbons
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Syntheses of large polycyclic aromatic hydrocarbons (PAHs) and graphene nanostructures demand methods that are capable of selectively and efficiently fusing large numbers of aromatic rings, yet such methods remain scarce. Herein, we report a new approach
- Kiel, Gavin R.,Ziegler, Micah S.,Tilley, T. Don
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supporting information
p. 4839 - 4844
(2017/04/11)
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- Enantioselective synthesis of β-fluoro-β-aryl-α-aminopentenamides by organocatalytic [2,3]-sigmatropic rearrangement
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The tetramisole-promoted catalytic enantioselective [2,3]-sigmatropic rearrangement of quaternary ammonium salts bearing a (Z)-3-fluoro-3-arylprop-2-ene group generates, after addition of benzylamine, a range of β-fluoro-β-aryl-α-aminopentenamides containing a stereogenic tertiary fluorine substituent. Cyclic and acyclic nitrogen substituents as well as various aromatic substituents are tolerated, giving the β-fluoro-β-aryl-α-aminopentenamide products in up to 76% yield, 96:4 dr, and 98:2 er.
- Kasten, Kevin,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 5182 - 5185
(2017/11/06)
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- One-pot enyne metathesis/Diels-Alder/oxidation to six-membered silacycles with a multi-ring core: Discovery of novel fluorophores
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Polycyclic compounds containing a six-membered silacycle are important. However, we have limited knowledge of the nature of these six-membered silacycles because methodologies for their synthesis remain under-developed. Here, we have developed a one-pot e
- Yoshioka, Shohei,Fujii, Yuki,Tsujino, Hirofumi,Uno, Tadayuki,Fujioka, Hiromichi,Arisawa, Mitsuhiro
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supporting information
p. 5970 - 5973
(2017/07/10)
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- Tridentate Lewis-acids based on triphenylsilane
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Several derivatives of the propeller-shaped ortho-substituted triphenylsilanes, carrying metal- or silicon-based acceptor groups, are reported. They were synthesized starting from tris(2-bromophenyl)fluorosilane, tris(2-vinylphenyl)fluorosilane and tris(2
- Tomaschautzky, Janek,Neumann, Beate,Stammler, Hans-Georg,Mix, Andreas,Mitzel, Norbert W.
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p. 1645 - 1659
(2017/02/10)
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- Ruthenium-Catalyzed Cycloisomerization of 2,2′-Diethynyl- biphenyls Involving Cleavage of a Carbon-Carbon Triple Bond
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A ruthenium complex catalyzes a new cycloisomerization reaction of 2,2′-diethynylbiphenyls to form 9-ethynylphenanthrenes, thereby cleaving the carbon-carbon triple bond of the original ethynyl group. A metal-vinylidene complex is generated from one of th
- Matsuda, Takanori,Kato, Kotaro,Goya, Tsuyoshi,Shimada, Shingo,Murakami, Masahiro
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supporting information
p. 1941 - 1943
(2016/02/14)
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- FUSED HETERO CYCLIC COMPOUND AND ORGANIC LIGHT EMITTING DEVICE USING THE SAME
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The present invention relates to a hydrocarbon-based fused-ring compound and an organic light emitting device including the same. The compound of the present invention can be used as a material for an organic material layer of the organic light emitting d
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Paragraph 0103-0106
(2016/10/08)
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- Diisobutylaluminum hydride-promoted cyclization of benzyl and phenylsilyl ethers bearing a 2-(trimethylsilyl)ethynyl group: syntheses of indenes and benzosiloles
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The reaction of o-[2-(trimethylsilyl)ethynyl]benzyl methyl ethers with diisobutylaluminum hydride (DIBAL-H) gave 2-(trimethylsilyl)indenes in good yields. This cyclization proceeds by regio- and stereoselective hydroalumination of the alkyne moiety followed by intramolecular nucleophilic substitution. o-[2-(Trimethylsilyl)ethynyl]phenylsilyl methyl ethers also underwent the DIBAL-H promoted-cyclization to be converted into 2-(trimethylsilyl)benzosiloles in good yields. This approach provides straightforward and efficient way to construct benzosiloles from readily available organosilanes.
- Kinoshita, Hidenori,Fukumoto, Hiroki,Tohjima, Takayuki,Miura, Katsukiyo
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supporting information
p. 3571 - 3574
(2016/07/18)
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- Organic electroluminescent material and preparation method thereof and organic electroluminescent device
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The invention relates to an organic electroluminescent material and a preparation method thereof and an organic electroluminescent device. According to the organic electroluminescent material, a benzo[g] bending structure is adopted as the center, a first benzene ring is introduced into the site g of the benzo[g] bending structure, then a second benzene ring is used for replacing hydrogen groups on the first benzene ring, a nitrogen heterocyclic ring is used for replacing hydrogen groups on the second benzene ring, and the following structure shown in the description is achieved, wherein Ar is a nitrogen heterocyclic ring with the electron transport function. Compared with the prior art, the organic electroluminescent material has a very proper triplet state energy level, high glass-transition temperature, good heat stability and high carrier transport capacity, the preparation method is simple, operation is easy, the yield is high, and cost is low; the organic electroluminescent material serves as a main material to replace CBP to manufacture the organic electroluminescent device, lower turn-on voltage and higher maximum current efficiency are achieved, the turn-on voltage can be reduced by 0.5-1.1 V, and the maximum current efficiency can be improved by 18% to 24%.
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Paragraph 0097; 0098; 0099; 0100
(2016/10/17)
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