9-Silafluorenes via Base-Promoted Homolytic Aromatic Substitution (BHAS) – The Electron as a Catalyst
作者:Dirk Leifert、Armido Studer
DOI:10.1021/ol503574k
日期:2015.1.16
Transition-metal-free intramolecular radicalsilylation of 2-diphenylsilylbiaryls via base-promoted homolytic aromatic substitution (BHAS) to give 9-silafluorenes is reported. 2-Diphenylsilylbiaryls are readily prepared, and cross dehydrogenativesilylation occurs with tert-butylhydroperoxide (TBHP) as a cheap stoichiometric oxidant in the presence of a small amount of tetrabutylammonium iodide (TBAI)
A visible‐light inducedradicalsilylation to dibenzosiloles from biarylhydrosilanes is described. The products were obtained in satisfactory yields under mild and water/air compatible conditions, providing an efficient and practical method for the synthesis of difunctionalized siloles by using a cheap organic dye photocatalyst. The method is tolerated by a wide range of functional groups and has a
for the preparation of dibenzosiloles was developed through intramolecular C−H/Si−H dehydrogenative coupling strategy starting from biarylhydrosilanes. Both electro-donating and electro-withdrawing substitution groups were tolerated for this transformation, and the desired dibenzosilole products could be obtained in moderate to excellent yields. A sila-Friedel-Crafts reaction mechanism was proposed
作者:Heng Zhang、Rong-Bin Hu、Xiao-Yu Zhang、Shi-Xia Li、Shang-Dong Yang
DOI:10.1039/c4cc01238k
日期:——
A novel and efficient Pd-catalyzed C–H acetoxylation is described. The approach uses R2(O)P as a directing group to synthesize various substituted 2′-phosphoryl biphenyl-2-OAc compounds.
was developed. The use of arenediazonium tosylates and corresponding boron compounds allows a conversion in neat water in the presence of commercially available Pd(OAc)2under mild conditions with tolerance to a wide range of functional groups. A procedure particularly useful for the synthesis of di-ortho-substituted biaryls was developed. A simple, convenient, and environment-friendly procedure for