766-46-1Relevant academic research and scientific papers
Facile Synthesis of Dibenzotetracenedione Derivatives by Rhodium-Catalyzed [2+2+2] Cycloaddition/Spontaneous Aromatization
Aida, Yukimasa,Shibata, Yu,Tanaka, Ken
, p. 1823 - 1829 (2019)
It has been established that a cationic rhodium(I)/SEGPHOS complex catalyzes the [2+2+2] cycloaddition of biphenyl-linked 1,7-diynes with 1,4-naphthoquinone and anthracene-1,4-dione. Conveniently, spontaneous aromatization proceeded upon removal of the rhodium complex by passing the reaction mixture through an alumina column, to give the corresponding dibenzotetracenediones and dibenzopentacenediones, respectively, in good yields. The obtained dibenzotetracenedione could be readily transformed into the corresponding dibenzotetracene in good yield. This dibenzotetracene showed blue fluorescence with a good quantum yield, which was significantly higher than those of tetracene, tetrabenzotetracene, and hexabenzotetracene.
Diastereoselective Synthesis of the ABCD Ring System of Rubriflordilactone B
Roth, Hudson G.,Nicewicz, David A.
, p. 48 - 51 (2021/11/09)
A novel nine-step diastereoselective route to the ABCD ring system of the natural product rubriflordilactone B is reported. Use of an α-substituted butenolide derived from maleic anhydride facilitated a 1,4-conjugate addition to provide a diene. The order in which a ringclosing metathesis and enolate oxidation were performed on this compound dictated the relative stereochemistry of the target. The final product exhibited anisotropic effects during roomerature NMR studies, requiring elevatederature experiments to confirm its identity.
Iodocyclisation of Electronically Resistant Alkynes: Synthesis of 2-Carboxy (and sulfoxy)-3-iodobenzo[ b ]thiophenes
Chen, Shuqi,Flynn, Bernard L.
, p. 65 - 76 (2020/11/05)
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.
An on-surface Diels–Alder reaction
Albrecht, Florian,Castro-Esteban, Jesús,Fatayer, Shadi,Gross, Leo,Pérez, Dolores,Pe?a, Diego
, 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
Synthesis of selenium-containing biindolyls and their Diels–Alder reaction toward the synthesis of heteroannulated [a]- and [c]-carbazoles
Wang, Ruei-Yu,Kao, Wei-Ting,Shih, Tzenge-Lien
, p. 829 - 837 (2019/11/19)
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
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
Jin, Hongwei,Liu, Daohong,Liu, Yunkui,Zhou, Bingwei
, p. 1417 - 1424 (2020/04/27)
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.
Three-coordinate copper(II) alkynyl complex in C-C bond formation: The sesquicentennial of the glaser coupling
Warren, Timothy H.,Bakhoda, Abolghasem,Okoromoba, Otome E.,Greene, Christine,Boroujeni, Mahdi Raghibi,Bertke, Jeffery A.
, p. 18483 - 18490 (2020/11/27)
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.
Frustrated Lewis pair-catalyzed double hydroarylation of alkynes with: N -substituted pyrroles
Guo, Jing,Cheong, Odelia,Bamford, Karlee L.,Zhou, Jiliang,Stephan, Douglas W.
supporting information, p. 1855 - 1858 (2020/02/22)
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
Selective Synthesis of Phenanthrenes and Dihydrophenanthrenes via Gold-Catalyzed Cycloisomerization of Biphenyl Embedded Trienynes
Milián, Ana,Garciá-Garciá, Patricia,Pérez-Redondo, Adrián,Sanz, Roberto,Vaquero, Juan J.,Fernández-Rodríguez, Manuel A.
supporting information, p. 8464 - 8469 (2020/11/02)
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.
Copper-catalyzed (4+1) and (3+2) cyclizations of iodonium ylides with alkynes
Liang, Hao,He, Xiaobo,Zhang, Yaqi,Chen, Bin,Ouyang, Jia-Sheng,Li, Yongsu,Pan, Bendu,Subba Reddy, Chitreddy V.,Chan, Wesley Ting Kwok,Qiu, Liqin
, p. 11429 - 11432 (2020/10/12)
The copper(ii)-catalyzed (4+1) cyclizations and copper(i)-catalyzed (3+2) cycloadditions of iodonium ylides and alkynes were successfully developed by employing efficient and safe iodonium ylides instead of traditional diazo compounds. Highly functionaliz
