Triflic Anhydride (Tf2O)-Activated Transformation of Amides, Sulfoxides and Phosphorus Oxides via Nucleophilic Trapping

Trifluoromethanesulfonic anhydride (Tf2O) has found a wide range of applications in synthetic organic chemistry as a strong electrophilic activator leading to the transient generation of a triflate intermediate. This versatile triflate intermediate undergoes nucleophilic trapping with diverse nucleophiles to yield novel compounds. In this review, we describe the features and applications of triflic anhydride in organic synthesis reported in the past decade, especially in amide, sulfoxide, and phosphorus oxide chemistry through electrophilic activation. A plausible mechanistic pathway of each important reaction is also discussed.

An efficient and practical chemo-enzymatic route to (3R,3aR,6R,6aR)-hexahydrofuro[3,2-b]furan-6-amino-3-ol (6-aminoisomannide) from renewable sources

The synthesis of 6-aminoisomannide is easily achieved starting from the renewable, inexpensive and commercially available isosorbide, in 66% overall yield. A biocatalysed highly regioselective acetylation of the 3-endo hydroxyl group of isosorbide was followed by the stereospecific interconversion of the 6-exo hydroxyl group into azido group, through reaction with trifluoromethanesulfonic anhydride followed by nucleophilic displacement of the triflate group by sodium azide. Finally, reduction of the azido group and deacetylation of the 3-hydroxy group were performed one pot by using LiAlH4.

2-Iodosylbenzoic acid activated by trifluoromethanesulfonic anhydride: efficient oxidant and electrophilic reagent for preparation of iodonium salts

2-Iodosylbenzoic acid in the presence of trifluoromethanesulfonic anhydride is an efficient oxidant and electrophilic reagent useful for preparation of the corresponding alkenyl and aryliodonium salts. Compared to the previously reported...