Triflic acid

Abstract

(A) TfOH as Catalytic Reagent: An efficient metal-free diacetoxylation reaction of alkenes catalyzed in the presence of 10 mol% of triflic acid has been described by Gade.3a TfOH plays a double role in this process: it catalyzes the ring-opening of the intermediate epoxide as well as the subsequent acetylation of the hydroxyl group.(B) Addition to ?-Carbonylated Alkynes: Various vinyl trifluoromethylsulfonates have been recently isolated by the addition of triflic acid to the triple bond of propynoate derivatives. The stereoselectivity could be controlled by adjusting the reaction conditions. Moreover, the generated vinyl triflates are very reactive intermediates towards metal cross-coupling reactions. (C) Synthesis of Aryl Triflates: Another application of triflic acid was illustrated by the synthesis of a potential medicinal agent. After catalytic hydrogenation of the bromine atom, the corresponding naphthyridin was transformed by diazotization of the amine followed by a nucleophilic substitution with TfOH. The resulting aryl triflate was used in a selective Suzuki Miyaura cross-coupling to give the desired scaffold with good yield.© Georg Thieme Verlag Stuttgart . New York.