Benzenesulfonyl chlorides: new reagents for access to alternative regioisomers in palladium-catalysed direct arylations of thiophenes
作者:Kedong Yuan、Henri Doucet
DOI:10.1039/c3sc52420e
日期:——
The palladium-catalysedcoupling of benzenesulfonylchlorides with thiophene derivatives allows regioselective access to β-arylated thiophenes. The reaction proceeds with easily accessible catalyst, base and substrates, without oxidant or ligand and tolerates a variety of substituents on both the benzene and thiophene moieties.
β-selective direct arylation of (oligo)thiophenes is reported. Thanks to the use of a water/surfactant solution in combination with natural feedstock-derived undecanoic acid as an additive, this high-yielding C–H coupling could be performed regioselectively at room temperature.
A simple method has been developed for synthesis of γ-halo-enones. The approach employs a sequence involving initial indium-mediated allenylation reactions of phenacyl halides with propargyl bromide. This process is followed by acid-promoted rearrangement reactions of the formed homoallenic halohydrins. The new method can be incorporated into routes for the efficient synthesis of various five-membered