158715-24-3Relevant academic research and scientific papers
Improved synthesis of aryltrialkoxysilanes via treatment of aryl Grignard or lithium reagents with tetraalkyl orthosilicates
Manoso, Amy S.,Ahn, Chuljin,Soheili, Arash,Handy, Christopher J.,Correia, Reuben,Seganish, W. Michael,DeShong, Philip
, p. 8305 - 8314 (2004)
General reaction conditions for the synthesis of aryl(trialkoxy)silanes from aryl Grignard and lithium reagents and tetraalkyl orthosilicates (Si(OR)4) have been developed. Ortho-, meta-, and para-substituted bromoarenes underwent efficient metalation and silylation at low temperature to provide aryl siloxanes. Mixed results were obtained with heteroaromatic substrates: 3-bromothiophene, 3-bromo-4-methoxypyridine, 5-bromoindole, and N-methyl-5-bromoindole underwent silylation in good yield, whereas a low yield of siloxane was obtained from 2-bromofuran, and 2-bromopyridine failed to give silylated product. The synthesis of siloxanes via organolithium and magnesium reagents was limited by the formation of di- and triarylated silanes (Ar 2Si(OR)2 and Ar3SiOR, respectively) and dehalogenated (Ar-H) byproducts. Silylation at low temperature gave predominantly monoaryl siloxanes, without requiring a large excess of the electrophile. Optimal reaction conditions for the synthesis of siloxanes from aryl Grignard reagents entailed addition of arylmagnesium reagents to 3 equiv of tetraethyl- or tetramethyl orthosilicate at -30 °C in THF. Aryllithium species were silylated using 1.5 equiv of tetraethyl- or tetramethyl orthosilicate at -78 °C in ether.
Direct Hiyama Cross-Coupling of (Hetero)arylsilanes with C(sp2)-H Bonds Enabled by Cobalt Catalysis
Lu, Ming-Zhu,Ding, Xin,Shao, Changdong,Hu, Zhengsong,Luo, Haiqing,Zhi, Sanjun,Hu, Huayou,Kan, Yuhe,Loh, Teck-Peng
supporting information, p. 2663 - 2668 (2020/03/30)
We report a chelation-assisted C-H arylation of various indoles with sterically and electronically diverse (hetero)arylsilanes enabled by cost-effective Cp*-free cobalt catalysis. Key to the success of this strategy is the judicious choice of copper(II) fluoride as a bifunctional sliane activator and catalyst reoxidant. This methodology features a broad substrate scope and good functional group compatibility. The synthetic versatility of this protocol has been highlighted by the gram-scale synthesis and late-stage diversification of biologically active molecules.
Directed palladium(II)-catalyzed intermolecular anti-markovnikov hydroarylation of unactivated alkenes with (hetero)arylsilanes
Lu, Ming-Zhu,Loh, Teck-Peng,Luo, Haiqing,Hu, Zhengsong,Shao, Changdong,Kan, Yuhe
supporting information, p. 9022 - 9028 (2020/12/02)
We describe herein a regioselective palladium(II)catalyzed intermolecular hydroarylation of unactivated aliphatic alkenes with electronically and sterically diverse (hetero)arylsilanes under redox-neutral conditions. A removable bidentate 8-amino-quinoline auxiliary was readily employed to dictate the regioselectivity, prevent β-hydride elimination, and facilitate protodepalladation. This silicon-based protocol features a broad substrate scope with excellent functional group compatibility and enables an expeditious route to a variety of γ-aryl butyric acid derivatives in good yields with exclusive anti-Markovnikov selectivity.
