Reactivity of α-trifluoromethanesulfonyl esters, amides and ketones: Decarboxylative allylation, methylation, and enol formation

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

“…α-Trifluoromethylsulfonyl ketones, esters, and amides were prepared by displacement of the corresponding bromide ( Scheme 83 ) [ 112 , 118 ] or chloride ( Scheme 83 ,c) [ 118 – 119 ] under various conditions. Long reaction times and high temperatures were often required.…”

Development of Palladium-Catalyzed Decarboxylative Allylation of Electron-Deficient Sulfones and Identification of Unusual Side Products

“…As we have described previously, 15 exhaustive efforts were made to expand the substrate scope of allylic α,α-dialkylated triflylacetates. The acylation of triflone anions, other than that generated from sec-butyllithium and N-phenyltriflimide, was found to be quite challenging; extensive efforts to elaborate the substrate scope using other secondary alkyllithiums were fruitless.…”

“…High-resolution mass spectrometry (HRMS) was performed on a Kratos Concept-11A mass spectrometer with an electron beam of 70 eV at the Ottawa-Carleton Mass Spectrometry Center at the University of Ottawa, on a Bruker maXis impact Quadrupole-time-of-flight mass spectrometer in the positive ESI mode at the McGill Chemistry Mass Spectrometry Center, or a Sciex QSTAR XL hybrid quadrupole time-of-flight mass spectrometer in the positive ESI mode at the Carleton Mass Spectrometry Center. Compounds 1–2 , 3–5 , 6 , 7a–c , and 7e were prepared and characterized as previously reported.…”

“…We were pleased to observe that treatment of 1 with 5 mol % Pd 2 (dba) 3 and 20 mol % PPh 3 in tetrahydrofuran (THF) gave homoallylic sulfone 2 in high yield (92%) with short reaction times at room temperature (Figure ). , During the course of these studies, Tunge and Weaver published a report describing Pd-catalyzed decarboxylative allylation on similar phenyl sulfone systems such as 3 ; however, these substrates required noticeably more forcing conditions. Notably, a 1:1 ratio of allylation 4 to protonation 5 products was produced when PPh 3 was employed as the ligand; optimized conditions used BINAP and afforded products 4 and 5 in a ratio of 11.3:1.…”

Origin of Protonation Side Products in Pd-Catalyzed Decarboxylative Allylation Reactions: Evidence for In Situ Modification of Triphenylphosphine Ligand

“…Our work on DcA began with trifluoromethyl sulfone (triflone) 1, which gave exclusively allylation product 2 in high yield; protonation product 3 was not observed (Scheme 1a). 17,18 While this result was exciting, the substrate scope could not be expanded due to limitations of the synthetic methodology. In related work, Tunge and Weaver reported the DcA of phenyl sulfones such as 4; the protonation side product 6 was observed alongside allylation product 5 (Scheme 1b).…”