1942-39-8Relevant academic research and scientific papers
Mesoporous graphitic carbon nitride as a versatile, metal-free catalyst for the cyclisation of functional nitriles and alkynes
Goettmann, Frederic,Fischer, Anna,Antonietti, Markus,Thomas, Arne
, p. 1455 - 1460 (2007)
Mesoporous graphitic C3N4 was successfully employed as an effective catalyst for the cyclotrimerisation of various nitriles into triazine derivatives and the cyclisation of functional alkynes. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
MeOTf-catalyzed formal [4?+?2] annulations of styrene oxides with alkynes leading to polysubstituted naphthalenes through sequential electrophilic cyclization/ring expansion
Chen, Chao,Xi, Chanjuan,Zhang, Zeyu,Zou, Song
supporting information, (2021/12/30)
MeOTf-catalyzed formal [4 + 2] annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized, which undergoes sequential electrophilic cyclization/ring expansion. A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields. The reaction could also be carried out on gram scale.
Catalytic Dimerization of Alkynes via C-H Bond Cleavage by a Platinum-Silylene Complex
Innocent, Jean,Kato, Tsuyoshi,Ohta, Masaya,Tobisu, Mamoru,Yoshida, Tomoki
supporting information, p. 1678 - 1682 (2020/06/08)
The cyclodimerization of diphenylacetylene derivatives catalyzed by a platinum-silylene complex is reported. The reaction proceeds via the cleavage of a carbon-hydrogen bond at the position ortho to an alkynyl group, and no additives are needed. Platinum complexes bearing other common ligands, such as phosphines and NHCs, failed to promote this reaction, highlighting the utility of the silylene ligand in this reaction.
Iridium Halide Complexes [1,1-X2-8-SMe2-1,2,8-IrC2B9H10]2 (X = Cl, Br, I): Synthesis, Reactivity and Catalytic Activity
Molotkov, Alexander P.,Vinogradov, Mikhail M.,Moskovets, Alexey P.,Chusova, Olga,Timofeev, Sergey V.,Fastovskiy, Vasilii A.,Nelyubina, Yulia V.,Pavlov, Alexander A.,Chusov, Denis A.,Loginov, Dmitry A.
, p. 4635 - 4644 (2017/09/06)
The reactions of thallium salt Tl[7-SMe2-7,8-C2B9H10] with [(cod)RhCl]2 and [Cp*RuCl]4 are accompanied by room-temperature polyhedral rearrangement, giving rhoda- and ruthenacarboranes 1-co
Rhodium-catalyzed dimerization of diaryl acetylenes in the presence of grignard reagents: Synthesis of 1,2,3-triphenyl naphthalene derivatives
Qian, Pengcheng,Chen, Fan,Pan, Changduo
, p. 3242 - 3250,9 (2020/08/31)
An efficient Rh-catalyzed dimerization of diaryl acetylenes was achieved in the presence of Wilkinson catalyst, AgF2, and 1.5 equivalent of PhMgBr in toluene, providing the 1,2,3-triaryl naphthalene derivatives in moderate to good yields. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
Palladium-catalyzed annulation of 1,2-diborylalkenes and -arenes with 1-bromo-2-[(Z)-2-bromoethenyl]arenes: A modular approach to multisubstituted naphthalenes and fused phenanthrenes
Shimizu, Masaki,Tomioka, Yosuke,Nagao, Ikuhiro,Kadowaki, Tsugumi,Hiyama, Tamejiro
experimental part, p. 1644 - 1651 (2012/09/08)
(Z)-1,2-Diaryl-1,2-bis(pinacolatoboryl)ethenes underwent double-cross-coupling reactions with 1-bromo-2-[(Z)-2-bromoethenyl]arenes in the presence of [Pd(PPh3)4] as a catalyst and 3 M aqueous Cs2CO3 as a base in THF at 80 °C. The double-coupling reaction gave multisubstituted naphthalenes in good to high yields. Annulation of 1,2-bis(pinacolatoboryl)arenes with bromo(bromoethenyl)arenes in the presence of a catalyst system that consisted of [Pd2(dba)3] (dba=dibenzylideneacetone) and 2-dicyclohexylphosphino-2′,6′- dimethoxybiphenyl (SPhos) under the same conditions produced fused phenanthrenes in good to high yields. The first annulation coupling occurred regiospecifically at the bromoethenyl moiety. This procedure is applicable to the facile synthesis of polysubstituted anthracenes, benzothiophenes, and dibenzoanthracenes through a double annulation pathway by using the corresponding dibromobis[(Z)-2-bromoethenyl]benzenes as diboryl coupling partners. Copyright
Rhodium/phosphine/amine-HBr catalyst system for highly selective cross-cyclodimerization of aryl- and alkylalkynes: Efficient access to multisubstituted naphthalene derivatives
Sakabe, Koichi,Tsurugi, Hayato,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information; experimental part, p. 445 - 449 (2010/05/18)
The rhodium/phosphine/amine.HBr catalyst system directed toward the highly chemoselective synthesis of multisubstituted naphthalene derivatives from two different internal alkynes was investigated. Under N2 atmosphere, [(RhC1(cod)}2], PPh3, Py.HBr, 1a, 2a, o-xylene and 1- methylnaphthalene were placed in a 20 mL two-necked reaction flask equipped with a reflux condenser. After the mixture was heated at 160°C for 6 h, the consumption of 1a was checked by GC analysis. The resulting mixture was allowed to cool to room temperature and then concentrated under reduced pressure. The residue obtained was purified by column chromatography on silica gel with hexane as an eluent to give 3-phenyl-1,2-dipropylnaphthalene in 84% yield. The catalyst enabled the use of alkenes as the coupling components, providing the dihydronaphthalenes.
Reactivity of Titanium(II) Arene Derivatives with Substituted Alkynes. Cyclooligomerization Reactions and Crystal and Molecular Structure of 4-C4(C6H5)4>Ti2
Calderazzo, Fausto,Marchetti, Fabio,Pampaloni, Guido,Hiller, Wolfgang,Antropiusova, Helena,Mach, Karel
, p. 2229 - 2238 (2007/10/02)
By treating Ti(η6-toluene)2 (X = Cl: 1a, X = Br: 1b) with C2R2 (R = Me, Ph) tetraorganylcyclobutadiene complexes of formula Ti(η4-C4R4)2 (R = Ph, X = Cl: 2a, X = Br: 2b; R = Me, X = Br: 3b) have been obtained in good yields.Compound 2b has been studied by X-ray diffraction methods.The titanium atom possesses an approximate square pyramidal coordination, the apical position being occupied by the symmetrically bonded tetraphenylcyclobutadiene ring, the four bridging bromides to the two AlBr2 groups forming the base of the pyramid, 0.99 Angstroem away from the titanium atom.The tetrabromoaluminato moiety of 2b can be substituted by carbocyclic anionic ligands, such as Cp and COT, and the corresponding complexes 4 and Ti(4h4-C4Ph4)(COT) were obtained.The spectroscopic study of the Ti(η6-benzene)2/diphenylacetylene (DPA) system (X = Cl: 5a, X = Br: 5b) has revealed the existence of three products, corresponding to the 1:1, 1:2, and 1:3 molar ratios.The possible role of the known AlX3 * C4R4 complexes in this reaction is discussed.The cyclotrimerization reactions of substituted acetylenes in the presence of η6-arene titanium(II) complexes as precursors have been studied.In toluene or methylcyclohexane Ti(η6-toluene)2 was found to catalyze the formation of alkyl-substituted aromatic hydrocarbons from 2-butyne, phenylacetylene, and 1-hexyne at about 80 deg C over 15 h with turnovers (moles of converted alkyne per mole titanium) of about 520, 900, and 990, respectively.The cyclooligomerization of DPA in the presence of Ti(η6-benzene)>(μ-X)2(AlX2)>2 (X = Cl, Br) was studied in detail.The activity of the chloro derivative 5a is higher than that of the bromide catalytic precursor 5b.In addition to hexaphenylbenzene and octaphenylcyclooctatetraene, other oligomerization by-products (triphenylethylene, 1,1,2,2-tetraphenylethane, 1,2,3-triphenylnaphthalene, and 1,2,3-triphenylazulene) were observed, whose formation was drastically reduced in the presence of alkyl aluminium halides. - Key Words: Titanium / Cyclooligomerization / Acetylenes, substituted / Tetraphenylcyclobutadiene, ligand
