Site-Divergent Alkenyl C–H Fluoroallylation of Olefins Enabled by Tunable Rhodium Catalysis

The unique properties of the fluorine-containing compounds
and
their widespread applications raise the demand for dependable synthetic
methods on the precise introduction of fluorine-containing substituents
into organic molecules. Herein, a site-divergent fluoroallylation
of olefins that can incorporate the fluoroallyl motif into different
alkenyl C–H sites is disclosed. gem-Difluorinated
cyclopropanes are employed as fluoroallyl sources via rhodium-catalyzed
C–C bond activation. This strategy can provide two regioisomeric
fluorinated skipped dienes in good yields with excellent site-selectivity.
The resulting products can serve as useful building blocks to access
various fluorine-containing molecules and are isosteric to β,
γ-unsaturated amides, which are promising to be exploited in
medicinal chemistry. Mechanistic studies revealed that the electronic
property of rhodium catalysts is crucial for the controllable excellent
site-selectivity, providing more insights beyond the methodology on
tuning the selectivity of metal catalysts.