Palladium-Catalysed Direct Desulfitative Arylation of Pyrroles using Benzenesulfonyl Chlorides as Alternative Coupling Partners
作者:Rongwei Jin、Kedong Yuan、Emmanuelle Chatelain、Jean-François Soulé、Henri Doucet
DOI:10.1002/adsc.201400736
日期:2014.12.15
AbstractThe reactivity of pyrrole derivatives for palladium‐catalysed desulfitative arylation has been investigated. 1‐Methyl‐, 1‐phenyl‐ and 1‐benzylpyrroles were successfully coupled with a variety of benzenesulfonyl chlorides using a phosphine‐free catalyst. Highly regioselective arylations at carbon C2 of pyrroles were observed in all cases. A wide variety of substituents on the benzenesulfonyl derivative was tolerated.It should be noted that even bromo‐ and iodo‐benzenesulfonyl chlorides were successfully coupled with pyrrole derivatives without cleavage of the CBr or CI bonds, allowing further transformations. Surprisingly, with indoles, mixtures of C2‐ and C3‐arylation products were obtained.magnified image