Fluoroalkyls, alkenes, alkynes

Konno T, Chae J, Tanaka T, Ishihara T, Yamanaka H. Highly regio and stereoselective hydrometallation reactions of fluorine-containing internal alkynes novel approaches to fluoroalkylated alkenes. J. Fluorine Chem. 2006 127 36-43. 

U nder thermal or Lewis acid catalyzed conditions, reactions of fluoroalkyl carbonyl compounds with alkenes usually provide the ene adduct. " One example of a [2 + 2] cycloaddition between hexafluoroacetone and an alkyne has been reported. ... 

Fluoroalkyl(aryl)iodonium salts are the most stable and practically important class of alkyl(aryl)iodonium derivatives. The application of such salts as electrophilic fiuoroalkylating reagents was reviewed in 1996 by Umemoto [1017]. Perfluoroalkyl(phenyl)iodonium trifiates (FITS reagents) 764 are efficient perfluoroalky-lating reagents toward various nucleophiUe substrates, sueh as arenes, carbanions, alkynes, alkenes, carbonyl compounds, amines, phosphines and sulfides [1017]. Scheme 3.300 shows several representative examples of electrophilic perfluoroalkylations using FITS reagents. 

RXN66 Addition of Fluoroalkyl Iodides to Alkenes or Alkynes via a Pd(l) Species... 

The insertion-P-elimination equilibrium is displaeed in the direction of the insertion for alkenes and alkynes bearing electron-withdrawing substituents. Thus, in the examples above and below, the metal-fluoroalkyl complexes are stable, even with 16 valence electrons and one p hydrogen atom. 

Konno T, Taku K, Yamada S, Moriyasu K, Ishihara T. Remarkable access to fluoroalkylated trisubstituted alkenes via highly stereoselective cobalt-catalyzed hydrosilylation reaction of fluoroalkylated alkynes. Org. Biomol. Chem. 2009 7 1167-1170. 

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