- Facile Construction of Yttrium Pentasulfides from Yttrium Alkyl Precursors: Synthesis, Mechanism, and Reactivity
-
Treatment of the yttrium dialkyl complex TpMe2Y(CH2Ph)2(THF) (TpMe2 = tri(3,5 dimethylpyrazolyl)borate, THF = tetrahydrofuran) with S8 in a 1:1 molar ratio in THF at room temperature afforded a yttrium pentasulfide TpMe2Y(κ4-S5) (THF) (1) in 93% yield. The yttrium monoalkyl complex TpMe2CpYCH2Ph(THF) reacted with S8 in a 1:0.5 molar ratio under the same conditions to give another yttrium pentasulfide [(TpMe2)2Y]+[Cp2Y(κ4-S5)]? (10) in low yield. Further investigations indicated that the S52- anion facilely turned into the corresponding thioethers or organic disulfides, and released the redundant S8, when it reacted with some electrophilic reagents. The mechanism for the formation of the S52- ligand has been investigated by the controlling of the reaction stoichiometric ratios and the stepwise reactions.
- Zhang, Fangjun,Zhang, Jie,Zhou, Xigeng
-
p. 2070 - 2077
(2017/02/26)
-
- Synthesis by FVT and characterization of unhindered silanethiones
-
The retro-ene reaction of allylthio- and propargylthiosilanes led, under flash vacuum thermolysis (FVT) conditions, to unhindered silanethiones, characterized by their derivatives, and also directly by coupling of the FVT with gas-phase spectrometries. Monomeric silicon oxysulfide has been generated similarly. The unsubstituted silanethione was not obtained, but dehydrogenated into silicon monosulfide during FVT.
- Lefevre, Valerie,Ripoll, Jean-Louis
-
p. 371 - 372
(2007/10/03)
-
- Dimethylsilanethione - Generation by retro-ene reaction and cycloaddition with ketene
-
Dimethylsilanethione was cleanly generated, under flash vacuum thermolysis conditions, by retro-ene cleavage of propargylthiodimethylsilane. The cothermolysis of this latter and ketene dimer led in 60% yield to an only [2 + 2] cycloadduct, 2,2-dimethyl-4-methylene-2-sila-3-thiaoxetane, which in turn can be cleaved at higher temperature to give hexamethylcyclotrisiloxane.
- Lefevre, Valerie,Dat, Yves,Ripoll, Jean-Louis
-
p. 7017 - 7018
(2007/10/03)
-
- METALLA IV-b-PHOSPHOLANNES II-METALLA-2 (OXA-, THIA- ou AZA-)-3 PHOSPHOLANNES
-
2-sila-, germa- or stanna- 3-(oxa-, thia- or aza-) phospholanes have been synthesized by reactions of dihalometalla-IV-b compounds with dilithiated β-phosphorus alcohols, thiols or amines HYCH2CH2P(H)Ph (Y=O, S, NMe).Germa- and stanna- heterocycles can also be obtained from germyl- or stannyldiamines and the same β-phosphorus alcohols, thiols or amines. 2-sila 3-(oxa- or thia-) phospholanes are of particular interest for their decomposition reaction leading to silanone or silathione and phosphirane.
- Andriamizaka, J. D.,Escudie, J.,Couret, C.,Satge, J.
-
p. 279 - 286
(2007/10/02)
-
- SILICIUM-VERBINDUNGEN MIT STARKEN INTRAMOLEKULAREN STERISCHEN WECHSELWIRKUNGEN X. NEUE WEGE ZU 1,3,2,4-DITHIADISILETANEN
-
2,2,4,4-Tetraorganyl-1,3,2,4-dithiadisiletanes containing bulky organyl groups are obtained by copyrolysis of the disilanes R3Si-SiR3 with sulfur or sulfur hexafluoride, or better by reaction of the disilanes R2HSi-SiHR2 (R=CH3, i-C3H7, cyclo-C6H11, t-C4H9) with sulfur.In the case of R=t-C4H9 a considerable amount of the t-butyl groups is isomerized to the less crowded isobutyl groups.Monomeric silathiones R2Si=S are not available by this route.The sulfur insertion reaction into 1,1-di-t-butyl-1-silacyclobutane yields 2,4-di-t-butyl-2,4-dipropyl-1,3,2,4-dithiadisiletane instead of the expected 1,1-di-t-butyl-1-sila-2-thiacyclopentane.The latter compound, however, results from the crown ether catalyzed cyclisation reaction of 3-bromopropyltrichlorosilane with Na2S followed by transalkylation with t-butyllithium.The iodosilanes R3SiI (R=i-C3H7, cyclo-C6H11) react with Na2S to give the corresponding hexaorganyldisilathianes in high yields.
- Weidenbruch, M.,Schaefer, A.,Rankers, R.
-
p. 171 - 184
(2007/10/02)
-