251633-66-6Relevant articles and documents
Regioselective Synthesis of α-Fluorinated Cyclopentenones by Organocatalytic Difluorocyclopropanation and Fluorine-Directed and Fluorine-Activated Nazarov Cyclization
Fuchibe, Kohei,Takayama, Ryo,Yokoyama, Takaharu,Ichikawa, Junji
, p. 2831 - 2838 (2017/03/06)
Silyl dienol ethers, prepared from α,β-unsaturated ketones, underwent proton sponge-catalyzed difluorocyclopropanation with trimethylsilyl 2,2-difluoro-2-fluorosulfonylacetate in a regioselective manner, leading to 1,1-difluoro-2-siloxy-2-vinylcyclopropanes in good yields. The cyclopropanes thus obtained were in turn subjected to fluoride-ion-catalyzed ring opening to afford 1-fluorovinyl vinyl ketones (i.e., Nazarov precursors). Treatment of the precursors with Me3Si+B(OTf)4?regioselectively promoted the Nazarov cyclization, the rate and regioselectivity of which were drastically enhanced by the fluoro substituent, which thus facilitated efficient synthesis of biologically promising α-fluorocyclopentenone derivatives.
