38274-16-7Relevant academic research and scientific papers
Chiral-at-Metal Phosphorescent Square-Planar Pt(II)-Complexes from an Achiral Organometallic Ligand
Schulte, Thorben R.,Holstein, Julian J.,Krause, Lennard,Michel, Reent,Stalke, Dietmar,Sakuda, Eri,Umakoshi, Keisuke,Longhi, Giovanna,Abbate, Sergio,Clever, Guido H.
, p. 6863 - 6866 (2017)
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
FLPNO Nitroxide Radical Formation by a 1,1-Carboboration Route
Liedtke, René,Eller, Christina,Daniliuc, Constantin G.,Williams, Kamille,Warren, Timothy H.,Tesch, Matthias,Studer, Armido,Kehr, Gerald,Erker, Gerhard
, p. 55 - 61 (2016)
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.
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)
De, Sukanya,Jash, Moumita,Chowdhury, Chinmay
, p. 15659 - 15662 (2020)
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
Rearrangement of a Transient Gold Vinylidene into Gold Carbenes
Debrouwer, Wouter,Fürstner, Alois
, p. 4271 - 4275 (2017)
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.
Palladium-Catalyzed Cascade Cyclization of Alkene-Tethered Aryl Halides with o-Bromobenzoic Acids: Access to Diverse Fused Indolo[2,1- A[isoquinolines
Yang, Xiumei,Lu, Haiyan,Zhu, Xiaoming,Zhou, Liwei,Deng, Guobo,Yang, Yuan,Liang, Yun
, p. 7284 - 7288 (2019)
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.
Improved stability of a metallic state in benzothienobenzothiophene-based molecular conductors: an effective increase of dimensionality with hydrogen bonds
Higashino, Toshiki,Ueda, Akira,Yoshida, Junya,Mori, Hatsumi
, p. 3426 - 3429 (2017)
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.
An on-surface Diels–Alder reaction
Albrecht, Florian,Castro-Esteban, Jesús,Fatayer, Shadi,Gross, Leo,Pérez, Dolores,Pe?a, Diego
supporting information, p. 26346 - 26350 (2021/11/13)
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
Alumina-Mediated π-Activation of Alkynes
Akhmetov, Vladimir,Amsharov, Konstantin,Feofanov, Mikhail,Sharapa, Dmitry I.
supporting information, p. 15420 - 15426 (2021/09/30)
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.
Copper-Catalyzed Chemoselective Silylative Cyclization of 2,2′-Diethynylbiaryl Derivatives
Zhao, Meng,Wang, Ying,Wang, Zi-Lu,Xu, Jian-Lin,Dai, Kai-Yang,Xu, Yun-He
supporting information, p. 3859 - 3863 (2021/05/26)
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.
Preparation of Structurally and Electronically Diverse N → B-Ladder Boranes by [2 + 2 + 2] Cycloaddition
Schepper, Jonas D. W.,Orthaber, Andreas,Pammer, Frank
, p. 14767 - 14776 (2021/10/25)
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
