Improved Synthesis of Aryltrialkoxysilanes via Treatment of Aryl Grignard or Lithium Reagents with Tetraalkyl Orthosilicates
作者:Amy S. Manoso、Chuljin Ahn、Arash Soheili、Christopher J. Handy、Reuben Correia、W. Michael Seganish、Philip DeShong
DOI:10.1021/jo048667h
日期:2004.11.1
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
Improved Synthesis of Aryltriethoxysilanes via Palladium(0)-Catalyzed Silylation of Aryl Iodides and Bromides with Triethoxysilane
作者:Amy S. Manoso、Philip DeShong
DOI:10.1021/jo010621q
日期:2001.11.1
silylation of aryl halides with triethoxysilane has been expanded to include aryl bromides. A more general Pd(0) catalyst/ligand system has been developed that activates bromides and iodides: palladium(0) dibenzylideneacetone (Pd(dba)(2)) is activated with 2-(di-tert-butylphosphino)biphenyl (Buchwald's ligand) (1:2 mol ratio of Pd/phosphine). Electron-rich para- and meta-substituted aryl halides (including
Preparation and Palladium-Catalyzed Cross-Coupling of Aryl Triethylammonium Bis(catechol) Silicates with Aryl Triflates
作者:W. Michael Seganish、Philip DeShong
DOI:10.1021/jo035309q
日期:2004.2.1
Pentavalent aryl and heteroaryl bis(catechol) silicates undergo palladium-catalyzedcross-coupling with aryl and heteroaryl triflates in the presence of a fluoride source in excellent yields. These solid, air-stable bis(catechol) silicates are prepared from a high-yielding displacement reaction between catechol and an aryl siloxane in the presence of an amine base. The cross-couplingreaction is tolerant