Synthesis 2020; 52(13): 1947-1958
DOI: 10.1055/s-0039-1691744
paper
© Georg Thieme Verlag Stuttgart · New York

Synthesis and Application of Tetrafluoroethylene (CF2CF2)-Containing Acetylene Derivatives

Gen Egashira
,
Chihiro Kajimoto
,
Takuto Kataoka
,
Shigeyuki Yamada
,
Tsutomu Konno
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Publication History

Received: 06 January 2020

Accepted after revision: 06 February 2020

Publication Date:
05 March 2020 (online)


Abstract

On treating 1,3,4-tribromo-1,1,2,2-tetrafluorobutane, readily prepared from commercially available 4-bromo-3,3,4,4-tetrafluorobut-1-ene, with 3.3 equivalents of LHMDS at 0 °C in THF, the corresponding lithium acetylide could be prepared quantitatively. The acetylide reacted well with various aldehydes, ketones, or chlorosilanes to give the corresponding acetylene derivatives in high yields. It was also found that various iodoarenes could participate in the cross-coupling reaction with the zinc acetylide, readily prepared from the lithium acetylide and ZnCl2·TMEDA complex, in the presence of Pd(PPh3)4 to bring about the adducts in high yields. Thus-obtained acetylene derivatives underwent smooth Diels–Alder reaction with various 1,3-dienes to afford the corresponding 1,4- or 1,3-cyclohexadiene derivatives. In addition, it was revealed that the oxidative aromatization of the resulting cyclohexadiene derivatives with DDQ took place very smoothly, providing the multi-substituted benzene derivatives having a tetrafluoro­ethylene group.

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