13688-68-1Relevant articles and documents
Synthesis and characterization of novel covalent biphenyldiyl Sm(II) and Yb(II) complexes
Chauvin, Yves,Marchal, Nathalie,Olivier, Helene,Saussine, Lucien
, p. 93 - 97 (1993)
Biphenylene reacts with activated Sm and Yb powders in ethers giving 2,2'-biphenyldiyl-Sm(II) and -Yb(II) complexes by opening of the C4 ring.They have been characterized by reactions with electrophiles such as the proton and dimethyldichlorosilane, and by 1H, 13C and 171Yb NMR measurements.The Yb complex can be obtained by reaction of 2,2'-dilithiobiphenyl with YbI2.Octamethylbiphenylene, the reduction potential of which is much more negative than that of biphenylene, does not react with Yb powder.In contrast, tricarbonyloctamethylbiphenylenechromium reacts with metal powder due to the presence of the electron-withdrawing Cr(CO)3 group.This suggests that an electron transfer from the metal precedes the opening of the cyclobutane ring.
THE CHEMISTRY OF SILOLES. SYNTHESIS AND REACTIONS OF η6-CHROMIUM TRICARBONYL
Ishikawa, Mitsuo,Tabohashi, Tatsuru
, p. C4 - C6 (1984)
η6-chromium tricarbonyl (II) was prepared by the reaction of 1-methyl-1-(trimethylsilyl)dibenzosilole with chromium hexacarbonyl.The reaction of II with methyllithium in THF gave η6-(1,1-dimethyldibenzosilacyclopentadiene)chromium tricarbonyl.Similar reaction of II with butyllithium, followed by oxidation, gave 1-butyl-1-methyldibenzosilole and 1,1-dibutyldibenzosilole, while reaction with (methyldiphenylsilyl)lithium under similar conditions afforded 1-methyl-4-(methyldiphenylsilyl)-1-(trimethylsilyl)dibenzosilole.
Arsenic-Bridged Silafluorene and Germafluorene as a Novel Class of Mixed-Heteroatom-Bridged Heterofluorenes
Sasaki, Hiroshi,Akioka, Ippei,Imoto, Hiroaki,Naka, Kensuke
, p. 1390 - 1395 (2021)
Arsenic-bridged silafluorene and germafluorene were synthesized as a novel class of mixed-heteroatom-bridged heterofluorenes. Their structures, photophysical properties, and electronic natures were studied by experimental and computational means. The doubly-bridged biphenyl moieties were distorted from the reported singly-bridged ones. The intersystem crossing from the singlet excitation states to the triplet ones was enhanced by the arsenic-bridging structures, implying that bridging through an arsenic atom is favorable for phosphorescence.
Synthesis and characterization of dibenzannulated silole dianions. The 1,1-dilithiosilafluorene and 1,1'-dilithiobis(silafluorene) dianions
Choi,Boudjouk
, p. 6685 - 6688 (2000)
Stirring of 1,1-dichloro-SiFl (1), (SiFl, silafluorene) in THF with excess lithium for 1 h gave a dark green solution of 1,1-dilithio-SiFl (2) in high yield. The dark red solution of the intermediate 1,1'-dilithio-(SiFl)2 (3) was also observed from this reaction within 10 min. Treatment of 2 with excess trimethylchlorosilane gave the 1,1-bis(trimethylsilyl)-SiFl derivative (4) in 95% yield. Treatment of the dark red solution of 3 and 2 with excess methyliodide gave the 1,1'-dimethyl-bis(SiFl) (5) and 1,1-dimethyl-SiFl (6) derivatives in a 4:1 ratio. The upfield locations of the 29Si resonances of dianions 2 and 3 (-1.09 ppm and -39.25 ppm, respectively) are consistent with π-electron localization on the silicon atoms. (C) 2000 Elsevier Science Ltd.
TRICYCLIC HETEROCYCLES WITH BIFUNCTIONAL SILICON CENTERS
Corey, Joyce Y.,Jonh, Christy S.,Ohmsted, Martha C.,Chang, Lihsueh S.
, p. 93 - 106 (1986)
Condensation of the diorganometallic reagents, (o-MC6H4)2X (M = Li, MgCl) with HSiCl3 followed by reduction with LiAlH4 provides dibenzosilacycles, I (a, X = -; b, X = NMe; c, X = CH2; d, X = CH2CH2) with two exocyclic H-substituents, =SiH2.Conditions for the stepwise conversion of I to mixed bifunctional systems, =SiHX (II, X = Cl, Br; III, X = OR), and bifunctional derivatives, =SiX2 (IV, X = Cl; V, X = OR) were determined.Controlled halogenation of I to II was accomplished with one molar equivalent of SO2Cl2 or NBS although CCl4 in the presence of ClRh(PPh3)3 or PdCl2 results in slow monochlorination.The reaction of I with excess SOCl2 or SO2Cl2 converts I to III but the latter is faster and provides fewer side reactions.Conversion of I to IV with excess alcohols occurs in high yield with ClRh(PPh3)3 but in low yield with H2PtCl6.Controlled alcoholysis of I to III could not be achieved except with tBuOH.The dichlorides, IV, are methylated in high yield to VII, =SiMe2.Reaction of Ib with ClRh(PPh3)3 results in elimination of H2 and formation of disilanes as indicated by trapping reactions with alcohols (formation of Vb).
UNEXPECTED BEHAVIOR OF SILOLES TOWARD ORGANOLITHIUM REAGENTS
Ishikawa, Mitsuo,Nishimura, Kunio,Sugisawa, Hiroshi,Kumada, Makoto
, p. C21 - C24 (1981)
The reaction of 5-trimethylsilyl-5-methyldibenzosilole (I) with an excess of methyllithium in THF afforded 5,5-dimethyldibenzosilole (II) in quantitative yield.Treatment of I with an excess of butyllithium gave 5,5-dibutyldibenzosilole (III) quantitatively.Similar treatment of II with butyllithium in THF at room temperature gave III in almost quantitative yield, while treatment of III with methyllithium at reflux temperature gave II and 5-butyl-5-methyldibenzosilole in 10 and 40percent yield, in addition to 37percent of the starting III. 1,2,5-Tris(trimethylsilyl)-1-methyl-3,4-diphenylsilole also reacted with methyllithium to give 1,1-dimethyl-2,2,5-tris(trimethylsilyl)-3,4-diphenyl-1-silacyclopent-3-ene and 1,1-dimethyl-2,5-bis(trimethylsilyl)-3,4-diphenylsilole in 70 and 7percent yield.A five-coordinate silicon compound is proposed as an intermediate.
Rhodium-Catalyzed Synthesis of Benzosilolometallocenes via the Dehydrogenative Silylation of C(sp2)-H Bonds
Murai, Masahito,Matsumoto, Koji,Takeuchi, Yutaro,Takai, Kazuhiko
, p. 3102 - 3105 (2015)
Use of a rhodium catalyst with electron-rich and bulky chiral diphosphine ligands having C2-symmetry allowed efficient dehydrogenative silylation of the C(sp2)-H bond of ferrocenes leading to chiral benzosiloloferrocenes. The substra
A Catalytic SEAr Approach to Dibenzosiloles Functionalized at Both Benzene Cores
Omann, Lukas,Oestreich, Martin
, p. 10276 - 10279 (2015)
A general procedure for the catalytic preparation of dibenzosiloles functionalized at one or both benzene rings starting from readily available ortho-silylated biphenyls is reported. This method provides rapid access to silole building blocks substituted with chlorine atoms at both phenylene groups, thereby allowing catalytic access to directly polymerizable dibenzosiloles. Moreover, it is shown that, despite the involvement of highly electrophilic intermediates, a considerable range of Lewis-basic, for example, oxygen- and nitrogen-containing, functional groups is tolerated. The mechanism of this intramolecular electrophilic aromatic substitution (SEAr) proceeds through a sulfur-stabilized silicon cation, generated catalytically from the hydrosilane precursor.
2,2′-Dilithiobiphenyl by direct lithiation of biphenylene
Lillo, Victor J.,Gómez, Cecilia,Yus, Miguel
, p. 2266 - 2269 (2009)
The reaction of biphenylene (1) with an excess of lithium powder (1:14 molar ratio) and a catalytic amount of DTBB (10 mol %) in THF at room temperature leads to the formation of the dilithiated species I by reductive opening of the four-membered ring. Further reaction of this intermediate with different electrophiles [Electrophile = H2O, D2O, Me3SiCl, t-BuCHO, Et2CO, n-Pr2CO, (CH2)5CO, Ph2CO and adamantanone] at 0 °C yields the corresponding products 2, after hydrolysis with water. Cyclisation of some representative examples of compounds 2 with H3PO4 gives the corresponding dibenzoxepines 3.
Synthesis of Dibenzosiloles through Electrocatalytic Sila-Friedel-Crafts Reaction
Han, Pan,Yin, Mengyun,Li, Haiqiong,Yi, Jundan,Jing, Linhai,Wei, Bangguo
supporting information, p. 2757 - 2761 (2021/04/16)
A novel electrocatalyzed method for the preparation of dibenzosiloles was developed through intramolecular C?H/Si?H dehydrogenative coupling strategy starting from biarylhydrosilanes. Both electro-donating and electro-withdrawing substitution groups were tolerated for this transformation, and the desired dibenzosilole products could be obtained in moderate to excellent yields. A sila-Friedel-Crafts reaction mechanism was proposed on the basis of previous literature and our controlled experiments. (Figure presented.).
