A redox-initiated per(poly)fluoroalkylation of olefins by per(poly)fluoroalkyl chlorides

Abstract

Reagents. In a typical run, to a stirred solution of sulfoxide 15 (251 mg, 1.0 mmol) in THF (10 mL) was added 1.58 M n-butyllithium (0.13 mL, 0.2 mmol) under N2 atmosphere at -78 °C.The mixture was stirred for 15 min at -78 °C. After hydrolysis and extraction with dichloromethane (3 X 20 mL), the extract was dried with anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel; eluent, hexane/EtOAc = 7/3) to give n-butyl p-tolyl sulfoxide (5a) in 13% and recovered sulfoxide 15 in 83% yield. Optical rotation (Md26) of the recovered sulfoxide 15 is 0°( c = 1.0, acetone).Reactions of 180-Labeled Phenyl p-Tolyl Sulfoxide (4c) with n -Butyllithium. The reaction was carried out according to the same procedure of the optically active sulfoxide 4b with n-butyllithium. The products were separated by column and preparative liquid chromatography, and their 180 contents were determined by mass spectrometry. The 180 content of each sulfoxide is 38 atom %.Cross-Over Reaction of18O-Labeled Diphenyl Sulfoxide (7b) and Unlabeled Di-p-tolyl Sulfoxide (8) with Phenyllithium. To a solution of sulfoxide 7b (101 mg, 0.5 mmol) and di-p-tolyl sulfoxide (8,115 mg, 0.5 mmol) in THF (10 mL) under N2 atmosphere at -78 °C was added 1.8 M phenyllithium (0.11 mL, 0.2 mmol) in ether/cyclohexane solution. After 15 min, water was added and the mixture was extracted with dichloromethane (3 X 20 mL). The extract was dried with anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure.The residue was purified by preparative liquid chromatography to afford diphenyl sulfoxide in 26%, phenyl p-tolyl sulfoxide in 51%, and di-p-tolyl sulfoxide in 17% yield. The 180 contents of three sulfoxides are 19 atom % by mass spectrometry.

Mn2(CO)10‐Visible Light Photomediated, Controlled Radical Polymerization of Main Chain Fluorinated Monomers and Synthesis of Block Copolymers Thereof

“…Unfortunately, while VDF polymerization can proceed at ambient temperature [37], only very low VDF telomers (DP <1-3) may be obtained, and only at high temperature (>100 • C) from transition metal salts and polyhalides by redox catalysis [1,26,38]. Moreover, while the 1:1 adduct formation by thermal or metal (Cu [39], Zn [40], Pd [41], SnCl 2 /CH 3 COOAg [42], Cp 2 TiCl [43], PPh 3 [44], AIBN [45,46], (NH 4 ) 2 S 2 O 8 /HCOONa [47]) catalyzed addition of R F -I derived perfluoroalkyl radicals to alkenes or of the R F -Mt-I (Zn [48,49], Zn/Cu [50]) organometallics to carbonyls and amides is available, the corresponding metal catalyzed addition of such electrophilic radicals to electrophilic fluorinated alkene substrates (FMs) at T <100 • C, and especially at ambient temperatures is conspicuously absent from the literature. Thus, to the best of our knowledge, prior to our recent work [51,52], there were no reports on metal-mediated FM or VDF polymerizations, let alone VDF-CRP.…”

Sulfur and Phosphorus Peroxides

“…Thus benzyl alcohols give aldehydes 74 , and in the presence of Ni(II) and ammonia they gives nitriles 75 ; secondary alcohols give the corresponding ketones 76 The per(poly)fluoroalkylation of olefins by per(poly)fluoroalkyl chlorides, initiated by ammonium peroxydisulfate and sodium formate, is also reported 78 . The reaction proceeds smoothly in polar aprotic solvents.…”

Tin-free Alternatives to the Barton-McCombie Deoxygenation of Alcohols to Alkanes Involving Reductive Electron Transfer

“…In 1991, Hu and Qing took advantage of this reactivity to carry out per(poly)fluoroalkylation of olefins by reduction of per(poly)fluoroalkyl chlorides. [49] Based on this seminal work, Kim et al developed a new method for the radical deoxygenation of alcohols from thiocarbonyl derivatives. Using a mixture of (Bu 4 N) 2 S 2 O 8 (3 equiv.…”