FLUOROSELENENYLATION OF ACETYLENES WITH XENON DIFLUORIDE-DIORGANYL DISELENIDES - SYNTHESIS AND STRUCTURE ELUCIDATION OF FUNCTIONALIZED VICINAL (E)-FLUORO(ORGANYLSELENO)OLEFINS
H. Poleschner et al., FLUOROSELENENYLATION OF ACETYLENES WITH XENON DIFLUORIDE-DIORGANYL DISELENIDES - SYNTHESIS AND STRUCTURE ELUCIDATION OF FUNCTIONALIZED VICINAL (E)-FLUORO(ORGANYLSELENO)OLEFINS, Liebigs Annalen, (7), 1996, pp. 1187-1193
We carried out the fluoroselenenylation of hex-3-yne with xenon difluo
ride and functionalized diselenides (dimethyl acetal- and carboxylic a
cid ester-substituted) to the corresponding substituted vicinal (E)-fl
uoro(organylseleno)olefins. Consecutive reactions afforded crystalline
2,4-dinitrophenyl-hydrazone and carboxylic acid derivatives. Nonfunct
ionalized vicinal (E)-fluoro(organylseleno)olefins were alkylated with
trimethyloxonium tetrafluoroborate, triethyloxonium tetrafluoroborate
, and methyl trifluoromethanesulfonate to the corresponding fluoroalke
nyldiorganylselenonium salts which were characterized either as tetraf
luoroborate or as tetraphenylborate salts. X-ray analysis of [(E)-4-fl
uorooct-4-en-5-yl]dimethylselenonium picrate (11) proved unambiguously
that the fluoroselenenylation of acetylenes with XeF2-R(2)Se(2) and X
eF2-PhSeSiR(3) reagents proceeds via trans additions.