Highly Efficient and Stereoselective Julia-Kocienski Protocol for the Synthesis of α-Fluoro-α,β-unsaturated Esters and Weinreb Amides Employing 3,5-Bis(trifluoromethyl)phenyl (BTFP) Sulfones
作者:Diego A. Alonso、Mónica Fuensanta、Enrique Gómez-Bengoa、Carmen Nájera
DOI:10.1002/adsc.200800194
日期:2008.8.4
α-Fluoroacetates 3 and Weinreb amide 4, bearing a α-[3,5-bis(trifluoromethyl)phenyl]sulfonyl (BTFP-sulfonyl) group at the α-position, are employed in the highly stereoselective synthesis of α-fluoro-α,β-unsaturated alkenoates and Weinrebamides, respectively. Aromatic and aliphatic aldehydes are condensed under extremely mild and simple reaction conditions using potassium carbonate in dimethylformamide
Synthesis of monofluoroalkenes via Julia–Kocienski reaction
作者:G.K. Surya Prakash、Anton Shakhmin、Mikhail Zibinsky、Istvan Ledneczki、Sujith Chacko、George A. Olah
DOI:10.1016/j.jfluchem.2010.06.009
日期:2010.11
Monofluoromethyl 3,5-bis(trifluoromethyl)phenyl sulfone 1 was synthesized and employed in Julia–Kocienski fluoroolefination reaction with various ketones and aldehydes. Optimal reaction conditions were found to be the treatment of substrates with KOH or CsF in DMSO at room temperature. Mixtures of (E) and (Z) isomers of monofluoroalkenes 4 were obtained in moderate to excellent yields. Download : Download