-[1-(-MeOPhenyl)vinyl]benzoate PMPVB as a recyclable auxiliary for C-O and C-S bond formation reactions under Brønsted acid catalysis.

A practically simple and useful method is reported for the synthesis of ethers and thioethers Brønsted acid-catalyzed activation of -[1-(-MeOphenyl)vinyl]benzoate (PMPVB) donors derived from alcohols. The mechanism of action is based on the remote activation of an active alkene followed by intramolecular 5- cyclization leading to a reactive intermediate that can react a substrate dependent S1 or S2 mechanism with alcohols and thiol nucleophiles providing facile access to ether and thioether functionalities, respectively.