- Silylcarboxylic Acids as Bifunctional Reagents: Application in Palladium-Catalyzed External-CO-Free Carbonylative Cross-Coupling Reactions
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A palladium-catalyzed external-CO-free carbonylative Hiyama-Denmark cross-coupling reaction is presented. The introduction of silylcarboxylic acids as bifunctional reagents (CO and nucleophile source) avoids the need for external gaseous CO and a silylarene coupling partner. The transformation features high functional group tolerance and it is successful with electron-rich, -neutral, and -poor aryl iodides. Stoichiometric studies and control experiments provide insight into the reaction mechanism and support the hypothesized dual role of silylcarboxylic acids. (Figure presented.).
- Li, Xiong,Xu, Jie,Li, Yue,Kramer, S?ren,Skrydstrup, Troels,Lian, Zhong
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- Sila- and Germacarboxylic Acids: Precursors for the Corresponding Silyl and Germyl Radicals
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Silicon-containing compounds are widely used as synthetic building blocks, functional materials, and bioactive reagents. In particular, silyl radicals are important intermediates for the synthesis and transformation of organosilicon compounds. Herein, we describe the first protocol for the generation of silyl radicals by photoinduced decarboxylation of silacarboxylic acids, which can be easily prepared in high yield on a gram scale and are very stable to air and moisture. Irradiation of silacarboxylic acids with blue LEDs (455 nm) in the presence of a commercially available photocatalyst releases silyl radicals, which can further react with various alkenes to give the corresponding silylated products in good-to-high yields with broad functional-group compatibility. This reaction proceeds in the presence of water, enabling efficient deuterosilylation of alkenes with D2O as the deuterium source. Germyl radicals were similarly obtained.
- Xu, Ning-Xin,Li, Bi-Xiao,Wang, Chao,Uchiyama, Masanobu
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supporting information
p. 10639 - 10644
(2020/04/29)
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- Synthesis of Aryl Silacarboxylates via Palladium-Catalyzed C-O Bond Formation of Silacarboxylic Acids and Aryl Iodides
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The first palladium-catalyzed C-O bond formation method for the synthesis of silacarboxylates by silacarboxylic acids with a broad range of aryl iodides and iodo-N-heterocycles is reported. Electron-deficient, electron-rich, and sterically hindered aryl iodides were well-tolerated to furnish the corresponding aryl silacarboxylates in moderate to excellent yields. Active functional groups, such as -NH2, -CHO, and allyl-, showed good tolerance, even in the large-scale synthesis. Double and triple esterification were also demonstrated to be effective.
- Liang, Jin-Yan,Shen, Shou-Jie,Xu, Xiao-Hu,Fu, Yun-Long
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supporting information
p. 6627 - 6631
(2018/10/31)
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- Silacarboxylic acids as efficient carbon monoxide releasing molecules: Synthesis and application in palladium-catalyzed carbonylation reactions
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Silacarboxylic acids have been demonstrated to be easy to handle, air-stable carbon monoxide precursors. Different silacarboxylic acids were synthesized from the corresponding chlorosilanes and carbon dioxide, and their decarbonylation, upon treatment with an array of activators, was evaluated. The release of CO from crystalline MePh2SiCO2H proved to be highly efficient, and it was successfully applied in a selection of palladium-catalyzed carbonylative couplings using near-stoichiometric quantities of carbon monoxide precursor. Finally, the synthesis of MePh2Si 13CO2H and its application in carbonyl labeling of two bioactive compounds was demonstrated.
- Friis, Stig D.,Taaning, Rolf H.,Lindhardt, Anders T.,Skrydstrup, Troels
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supporting information; experimental part
p. 18114 - 18117
(2012/01/04)
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