18080-90-5Relevant academic research and scientific papers
Synthesis of Silacyclohexanones from Divinylsilanes and Allylamines by a Rh-Catalyzed Cyclization
Guo, Jiawei,Liu, Song,Pang, Qinjiao,Zhang, Hongyun,Gao, Lu,Chen, Li,Song, Zhenlei
supporting information, p. 726 - 730 (2022/01/20)
An efficient synthesis of silacyclohexanones bearing a variety of silyl substituents has been developed by a [Rh(coe)2Cl]2/PCy3-catalyzed cyclization of divinylsilanes with Jun’s allylamine. The silacyclohexanones can be o
A Convergent Method for the Synthesis of Highly Enantiomerically Enriched Cyclic Silanes with Silicon-Centered Chirality
Oestreich, Martin,Schmid, Ulrike K.,Auer, Gertrud,Keller, Manfred
, p. 2725 - 2739 (2007/10/03)
A preparatively straightforward methodology has been developed which allows the assembly of silicon-containing carbocycles as mixtures of diastereomers with silicon as the sole center of stereogenic information. One-step construction of the chiral cyclic silanes is realized by reaction of equimolar amounts of a dibromide and a chirally modified dichlorosilane under Barbier conditions giving access to several monofunctionalized 1-sila-1,2,3,4-tetrahydronaphthalenes and a corresponding phenanthrene derivative. Facile large scale syntheses of 3-(2-bromoaryl)propyl bromides as well as dichlorosilanes have been elaborated. This highly convergent methodology relies on the novel (-)-menthyloxy-substituted dichlorosilanes, which have the chiral auxiliary for the subsequent optical resolution installed. These enantiopure dichlorosilanes are useful building blocks for a general and modular one-step approach to silanes with silicon-centered chirality since this strategy avoids the linear sequences reported in literature. The optical resolution has been exemplarily optimized for the 1-phenyl-1-sila-1,2,3,4- tetrahydronaphthalene derivative and the absolute configuration has been established by X-ray crystallography. The chiral auxiliary is stereospecifically displaced by simple reduction providing the highly enantioenriched silane (er = 98:2) which is enantiospecifically chlorinated as verified by a Walden inversion at silicon.
FLASH VACUUM THERMOLYSIS AND MASS SPECTROSCOPY OF 9,10-DIHYDRO-9-SILAANTHRACENES
Winkel, Yvar van den,Baar, Ben L. M. van,Bastiaans, Harold M. M.,Bickelhaupt, Friedrich,Schenkel, M.,Stegmann, H. B.
, p. 1009 - 1024 (2007/10/02)
The synthesis of 9,10-dibenzyl-9,10-diphenyl-9,10-dihydro-9-silaanthracene (8), and of some similarly substituted 9,10-dihydro-9-silaanthracenes is reported.Compound 8 was prepared with the aim of converting it by Flash Vacuum Thermolysis (FVT) into 9,10-diphenyl-9-silaanthracene (4), with 1,2-diphenylethane (5) as the expected byproduct.At lower temperatures, a surprisingly stable, dark green organic radical was formed, which was investigated by ESR and ENDOR spectroscopy and tentatively assigned the triphenylmethyl type structure 9.Both benzyl groups of 8 were efficiently cleaved off, presumably to give 4, and the yield of 5 was about 70percent at higher temperatures.However, no direct information on the existence of 4 was obtained, and it was concluded that it polymerizes under the conditions of reaction.Parallel to FVT experiments, the formation of ionized 9-silaanthracenes in the EI mass spectra of 8 and of analogues was investigated.Fragmentation leading to the ionized 9-silaanthracenes was found to be favoured by the presence of one or two phenyl groups at silicon in the precursor ion of a benzyl group and a hydrogen at the 10-carbon position.
