Rhenium-catalyzed aromatic propargylation

A mild aromatic propargylation reaction, employing an air- and moisture-tolerant rhenium-oxo complex ((dppm)ReOCl3) as a catalyst and a propargyl alcohol as the electrophile, is described. The reaction tolerates a broad range of functional groups and regioselectively affords propargylic arenas without formation of the isomeric allenyl adducts. The potential of this rhenium(V)-catalyzed reaction is exemplified by application of the propargylation to the synthesis of O-methyldetrol, mimosifoliol, and beta-apopicropodophyllin.