Synthesis and reactions of α-fluorinated vinyl building blocks

We prepared and examined several versatile mono-fluorinated building blocks bearing an a-fluorovinyl moiety. Each compound has a variety of heteroatoms such as phosphorus, silicon, stannane, and sulfur. This review mainly consists of the following four parts. 1) (alpha-Fluorovinyl)phosphonium salts underwent Michael addition followed by Wittig olefination to give the corresponding monofluoroethylene compounds in good yields. 2) alpha-Fluorovinylation with carbonyl compounds was carried out using (alpha-fluorovinyl)methyldiphenylsilane in the presence of TBAF. 3) Cross-coupling reaction of the silane with aryl halides smoothly proceeded giving the corresponding alpha-fluorinated styrene derivatives. 4) Carbonylative cross-coupling reaction of (alpha-fluorovinyl)tributylstannane with aryl halides and aryl triflates proceeded to afford the corresponding alpha-fluorovinyl aryl ketones under a CO atmosphere. Finally, 1, 1-difluoroethylene as a key fluoride source was employed in order to prepare the above building blocks.