Interaction of a C-F bond with the π-system of a C═C bond or "head on" with a proximate C-H bond

J Org Chem. 2012 Feb 3;77(3):1605-9. doi: 10.1021/jo2024152. Epub 2012 Jan 25.

Abstract

We describe the synthesis and preliminary study of two molecules, in which a fluorine atom is positioned proximately above the π-orbitals of a C═C bond or else wherein a C-F bond interacts in a "head on" fashion with a proximate C-H bond. The spectroscopic characteristics of these unusual interactions are documented, X-ray crystallographic analyses are reported, and theoretical calculations are employed to support the observed spectroscopy.