Synthesis and Properties of the Strained Alkene Perfluorobicyclo[2.2.0]hex-1(4)-ene

Abstract

The title fluoroalkene has been generated by dehalogenation of dibromide and diiodide precursors and trapped in situ. retro-Diels-Alder reaction of its adduct with N-benzylpyrrole has made the alkene available in high yield and purity. In sharp contrast to its extremely labile hydrocarbon counterpart, the fluoroalkene is very stable yet highly reactive. Its characterization includes its electron affinity, photoelectron spectrum, and the previously reported structure determination by electron diffraction.

Cycloaddition Chemistry of Tetrafluorothiophene S,S-Dioxide

“…The facility of retroreaction of pyrrole Diels−Alder adducts can be very useful, as illustrated in the synthesis of the very strained fluoroalkene octafluorobicyclohex-1(4)-ene. 9 To gain a sense of how strongly TFTDO prefers to act as dienophile rather than diene, energetics for the contrasting modes of reaction with furan were compared computationally ( Figure 2). 8 Surprisingly, both of the adducts obtained experimentally (31n, 31x) were found to lie well above the two in which TFTDO serves as the diene (33n, 33x).…”

“…Solvent was replaced with CD 2 Cl 2 for literature comparison, and a bit of CCl 3 F was added for calibration. 19 7,8,9,10-Tetrafluoro-6b,10a-dihydrofluoranthene (9). Technical-grade acenaphthylene was sublimed at atmospheric pressure and temperature up to 135°C.…”

Chemistry of the Highly Strained Alkene Perfluorobicyclo[2.2.0]hex‐1(4)‐ene

“…The same thing happened in [D 8 ]THF, but now the reaction was much faster and stopped after about 60 % conversion. [6] [4 + 2] Cycloadditions. Presumed chain propagation steps are shown in Scheme 4.…”

“…[1][2][3][4][5][6] The compound is a very reactive and versatile electrophile, yet it is also strikingly robust. [1][2][3][4][5][6] The compound is a very reactive and versatile electrophile, yet it is also strikingly robust.…”

“…[3] Its behavior is the more remarkable when compared with that of the parent hydrocarbon, which dimerizes and polymerizes at temperatures below zero. [6] Reactions were run either with isolated alkene prepared by flash vacuum pyrolysis of its Diels-Alder adduct with N-benzylpyrrole, or in situ by reduction of a dihalide adduct.…”