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

Abstract

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.

Recent Applications of Trifluoromethanesulfonic Anhydride in Organic Synthesis

“…[4][5][6][7][8][9] Other oxygen-containing nucleophiles, such as sulfoxides and phosphorus oxides could also undergo nucleophilic attack with Tf 2 O to generate thionium triflate, electrophilic P-species and phosphonium triflate. [10][11][12] These highly active transient species could readily undergo nucleophilic substitution reactions for further diverse transformations.…”

“…In recent years, there have been some review articles that generally summarize the electrophilic activation of amides, sulfoxides, and phosphorus oxides with Tf 2 O, [4][5][6][7][8][9][10][11][12] so these aspects would not been discussed here. In this review, we particularly focus on the recent advances in new applications of Tf 2 O in organic synthesis, which are devideded into three parts: a) activation of nitrogen-containing heterocycles and nitriles for further transformation; b) used as trifluoromethylation and trifluoromethylthiolation reagents for the synthesis of trifluoromethylated and trifluoromethylthiolated compounds; c) electrophilic activation of nitro group and nitrone for new reactions development.…”

Recent Applications of Trifluoromethanesulfonic Anhydride in Organic Synthesis

“…Additionally, electrophilic activation of tertiary and secondary amides with triflic anhydride under mild conditions gives rise to iminium and imino triflates, respectively, which could be utilized as versatile reagents to react with various C ‐, N ‐, O ‐ and S ‐nucleophiles for the transformation of an amide function into different products [4–9] . Other oxygen‐containing nucleophiles, such as sulfoxides and phosphorus oxides could also undergo nucleophilic attack with Tf 2 O to generate thionium triflate, electrophilic P ‐species and phosphonium triflate [10–12] . These highly active transient species could readily undergo nucleophilic substitution reactions for further diverse transformations.…”

“…[4][5][6][7][8][9] Other oxygen-containing nucleophiles, such as sulfoxides and phosphorus oxides could also undergo nucleophilic attack with Tf 2 O to generate thionium triflate, electrophilic P-species and phosphonium triflate. [10][11][12] These highly active transient species could readily undergo nucleophilic substitution reactions for further diverse transformations.…”

“…In recent years, there have been some review articles that generally summarize the electrophilic activation of amides, sulfoxides, and phosphorus oxides with Tf 2 O, [4][5][6][7][8][9][10][11][12] so these aspects would not been discussed here. In this review, we particularly focus on the recent advances in new applications of Tf 2 O in organic synthesis, which are devideded into three parts: a) activation of nitrogen-containing heterocycles and nitriles for further transformation; b) used as trifluoromethylation and trifluoromethylthiolation reagents for the synthesis of trifluoromethylated and trifluoromethylthiolated compounds; c) electrophilic activation of nitro group and nitrone for new reactions development.…”