Copper‐Catalyzed Direct Trifluoro‐ and Perfluoroalkylselenolations of Boronic Acids with a Shelf‐Stable Family of Reagents

Abstract

Herein the copper‐catalyzed direct perfluoroalkylselenolation of aryl‐ and vinylboronic acids is described for the first time. The key to success is the design of new shelf‐stable perfluoroalkylselenolating reagents, namely perfluoroalkyl tolueneselenosulfonates. The reaction occurs at room temperature in the presence of commercially available catalyst and ligand in catalytic quantities.magnified image

Difluoro(aryl)(perfluoroalkyl)‐λ4‐sulfanes and Selanes: Missing Links of Trichloroisocyanuric Acid/Potassium Fluoride Chemistry

“…One major reactivity question remained:d oes the selenium derivative behave more like sulfur or tellurium (i.e.with Se in the + 4o r+ 6o xidation state in the final product)?A small number of aryl(trifluoromethyl)selanes were synthesized and subjected to TCICA/KF conditions ( Table 2). [15][16][17][18] As Yagupolskiisr esults with XeF 2 /HF suggest, [6] we found that the selanes undergo difluorination similar to sulfanes. Thus,c ompounds 21-26 were formed in good yields.T he 19 FNMR data of 15,for instance,can be compared to those of 25:in15,signals at d = À11.89 ppm (2F,q, 3 J F-F = 18 Hz) and d = À61.74 ppm (3F,t, 3 J F-F = 18 Hz) are observed, and in 25, the corresponding signals appear at d = À73.21 ppm (2F,q , 3 J F-F = 12 Hz) and d = À58.30 ppm (3F,t, 3 J F-F = 12 Hz).…”

“…with Se in the +4 or +6 oxidation state in the final product)? A small number of aryl(trifluoromethyl)selanes were synthesized and subjected to TCICA/KF conditions (Table ) . As Yagupol'skii's results with XeF 2 /HF suggest, we found that the selanes undergo difluorination similar to sulfanes.…”

Synthetic Approaches to Trifluoromethylselenolated Compounds

“…Trifluoromethyl tolueneselenosulfonate has been successfully evaluated in cross-couplingp rocesses with aryl boronic acids under copperc atalysis conditions (Scheme 29). [40] The developed methodology demonstrated ab road compatibility with different aryl boronic acid starting materials, substituted with electron-withdrawing or -donating groups. The reaction was performed with copper(II) acetate (10 mol %) in conjunction with bpy (10 mol %) as al igand, cesium carbonate as a base in THF at room temperature.…”

“…Trifluoromethyl tolueneselenosulfonate has been successfully evaluated in cross‐coupling processes with aryl boronic acids under copper catalysis conditions (Scheme ) . The developed methodology demonstrated a broad compatibility with different aryl boronic acid starting materials, substituted with electron‐withdrawing or ‐donating groups.…”

Exploring the Reactivity of Trifluoromethyl Tolueneselenosulfonate with Alkynes under Copper Catalysis

“…[4,7] We designed recently an ew family of shelfstable reagents, namely perfluoroalkyl tolueneselenosulfonate. [8] With our continuous interest to develop new methodologies fort he incorporation of fluorinated moieties, we decided to investigate the direct formation of C(sp)ÀSeCF 3 through the direct coupling of alkynesw ith trifluoromethyl tolueneselenosulfonate under copperc atalysis. Regardingt he state of the art for the formation of C(sp)ÀSeCF 3 ,o nly few reports have been disclosed.…”