A novel synthesis of haloalkenes from aldehydes with carbon-carbon coupling

Fluorinated Ylides and Related Compounds

“…295 β-Hydroxy sulfoxides were readily converted to β-methyloxy sulfoxides by treatment with MeSO 2 Cl (Table 42). 296 When the β-mesyloxy sulfoxide was treated with butyllithium, the butyl group exclusively attacked a sulfur atom and resulted in the formation of fluoroolefin as a mixture of (E)and (Z)-isomers (eq 201). 296 After Swern oxidation of the hydroxy group of the adducts (eq 202), the sulfenyl group could be readily removed by treatment with ethyl Grignard reagent to give R-fluoro ketones in high yields.…”

“…296 When the β-mesyloxy sulfoxide was treated with butyllithium, the butyl group exclusively attacked a sulfur atom and resulted in the formation of fluoroolefin as a mixture of (E)and (Z)-isomers (eq 201). 296 After Swern oxidation of the hydroxy group of the adducts (eq 202), the sulfenyl group could be readily removed by treatment with ethyl Grignard reagent to give R-fluoro ketones in high yields. 297 The mechanism of the desulfinylation probably involved a ligand exchange reaction of sulfoxide to give a magnesium enolate.…”

Synthetic Methods for Fluorinated Olefins

“…The thermal desulfination of α-fluoro-β-ketosulfoxide products afforded α-fluorinated (Z)-alkenones in good overall yields. [24] Likewise, Lequeux and Pommelet reported the stepwise synthesis of an α-fluoro-α,β-unsaturated ester from the fluorinated tert-butylsulfide 7a. [25] In Julia olefinations of non-fluorinated substrates, the use of sulfoximines in place of sulfone functionalities is limited.…”

Thia-Wittig-like Reactions as a New Route for the Stereoselective Synthesis of (Z)-Fluoroalkenoates

“…3 Alternative approaches based on concerted elimination of β-mesyloxy sulfoxides afforded (E)-fluoroalkenes with moderate selectivity. 4 Concerning the preparation of the Z isomer, the most elegant and direct approach consisted of alkylating the ethyl phenylsulfinyl fluoroacetate to produce exclusively (Z)-fluoropropenoates by a stereoselective elimination of sulfenic acid. 5 On the other hand, a phenylselenenyl fluoride equivalent has been used to produce (Z)-fluoroalkenoates from diazoesters.…”

“…The widely used strategy to build ( E )-fluoroalkenoates from aldehydes is the Horner−Wadsworth−Emmons reaction (HWE), involving the commercially available triethyl 2-fluoro-2-phosphonoacetate . Alternative approaches based on concerted elimination of β-mesyloxy sulfoxides afforded ( E)- fluoroalkenes with moderate selectivity . Concerning the preparation of the Z isomer, the most elegant and direct approach consisted of alkylating the ethyl phenylsulfinyl fluoroacetate to produce exclusively ( Z )-fluoropropenoates by a stereoselective elimination of sulfenic acid .…”