Methods for the synthesis of gem-difluoromethylene compounds

This review deals with general and significant developments in the area of building block chemistry of lightly-fluorinated aliphatic compounds, that is, those that contain one, two, or three, fluorine atoms. For the purposes of the review, building blocks are small readily-available materials that already contain fluorine atoms. They are classified according to the number of carbon atoms supplied to the target molecule, rather than according to the number of fluorine atoms. Finally, certain fluorinated motifs which may be generated easily, and are then transformable in useful ways, are discussed.

Building Block Approaches to Aliphatic Organofluorine Compounds

The treatment of α-(trifluoromethyl)styrene with organolithium reagents results in the selective formation of gem-difluoroalkenes in good-to-excellent yields. This reaction has been applied to the synthesis of 3-gem-difluoro-2-phenylallylic amines and other functionalised gem-difluoroalkenes.

Takashi Mishima

Papers

SYNTHESES OF β, β-DIFLUOROCARBOXYLIC ACID DERIVATIVES THROUGH THE CLAISEN REARRANGEMENT OF 1, 1-DIFLUORO-1-ALKEN-3-OLS