Conversion of the Carbonyl Group to CF2 Using IF

Article abstract of DOI:10.1021/jo00015a024

A novel method for the transformation of CO -> CF2 is described.The easily made hydrazone derivatives of the carbonyl moiety are reacted under mild conditions with IF prepared directly from the corresponding elements.Various hydrazones have been examined and compared with each other.Unsubstituted ones are usually the most suitable although they are not always easy to purify and store.N-Methyl- and N,N-dimethylhydrazones also give quite satisfactory results.The more easily made dinitrophenyl hydrazones (DNPs), semicarbazones, and tosylhydrazones also react, but the yields of the desired CF2 compounds are usually lower.Oximes could also be successfully reacted.The two main byproducts of the reaction are the parent carbonyl compounds, which can be recycled, and the α-iododifluoro derivatives.The latter upon treatment with LiAlH4 or Bu3SnH were reduced to the desired product, thus increasing the overall yields.