Two-Stage Synthesis of 3-(Perfluoroalkyl)-Substituted Vinyldiazocarbonyl Compounds and Their Nonfluorinated Counterparts: A Comparative Study

Abstract

Two approaches for the synthesis of fluorinated (<i>F</i>) and nonfluorinated (<i>H</i>) 4-(alkoxycarbonyl)-substituted <i>cis</i>- and <i>trans</i>-vinyldiazocarbonyl compounds with substituents of variable stereoelectronic nature (H, Me, Ph, CF₃, OTBS) at the C-3 atom of the vinyl double bond from the relevant 1,3-dicarbonyl compounds were compared: a pathway using the Wittig reaction followed by a diazo transfer reaction was most efficient for the synthesis of the <i>H</i>-vinyldiazocarbonyl compounds (total yields of up to 60%), while the yields of their <i>F</i>-analogues under similar conditions did not exceed 16–37%. An approach via diazo transfer followed by the Wittig reaction, in contrast, is more effective for the preparation of <i>F</i>-vinyldiazocarbonyl compounds (total yields 37–69%). The configuration of the resulting <i>F</i>- and <i>H</i>-vinyldiazocarbonyl compounds is evidently controlled by the steric bulk of the substituent at the C-3 atom of the vinyl double bond and, in addition, depends on the specific synthetic pathway.