Toward Asymmetric Synthesis of Pentaorganosilicates was written by van der Boon, Leon J. P.;Fuku-en, Shin-ichi;Slootweg, J. Chris;Lammertsma, Koop;Ehlers, Andreas W.. And the article was included in Topics in Catalysis in 2018.Electric Literature of C8H4Br2S This article mentions the following:
Introducing chiral silicon centers was explored for the asym. Rh-catalyzed cyclization of dihydrosilanes to enantiomerically enriched spirosilanes as targets to enable access to enantiostable pentacoordinate silicates. The steric rigidity required in such systems demands the presence of two naphthyl or benzo[b]thiophene groups. The synthetic approach to the expanded spirosilanes extends Takai’s method (Kuninobu et al. in Angew Chem Int Ed 52(5):1520-1522, 2013) for the synthesis of spirosilabifluorenes in which both a Si-H and a C-H bond of a dihydrosilane are activated by a rhodium catalyst. The expanded dihydrosilanes were obtained from halogenated aromatic precursors. Their asym. cyclization to the spirosilanes were conducted with [Rh(cod)Cl]2 in the presence of the chiral bidentate phosphine ligands (R)-BINAP, (R)-MeO-BIPHEP, and (R)-SEGPHOS, including derivatives with P-(3,5-t-Bu-4-MeO)-Ph (DTBM) groups. The highest enantiomeric excess of 84% was obtained for 11,11′-spirobi[benzo[b]-naphtho[2,1-d]silole] with the DTBM-SEGPHOS ligand. In the experiment, the researchers used many compounds, for example, 2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7Electric Literature of C8H4Br2S).
2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7) belongs to benzothiophene derivatives. Benzothiophene scaffolds are of great importance due to its increased presence in bioactive molecules. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, and sertaconazole, and also BTCP.Electric Literature of C8H4Br2S
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem