Reaction of N-Chloro-N-fluoroperhaloalkylamines with Mercury. Facile Synthesis of N-Fluoro Imines and N-Fluoro Amines

Article abstract of DOI:10.1021/jo00320a010

The reaction of N-chloro-N-fluoroalkylamines with mercury has been studied with ClCF2NClF, CF3NClF, CF3CF2NClF, CF3CF2CF2NClF, and (CF2NClF)2.In the absence of solvents, all but CF3NClF undergo dehalogenation to form the corresponding N-fluoro imines in good yield.Only the syn isomers of CF3CF=NF, CF3CF2CF=NF, and (CF=NF)2 are observed.With trifluoroacetic acid as a solvent, the reactions with mercury yield the corresponding N-fluoro amines ClCF2NHF, CF3NHF, CF3CF2NHF, and CF3CF2CF2NHF in excellent yields except with (CF2NClF)2.For the latter, the amine (CF2NHF)2eliminates HF under the reaction conditions, and only (CF=NF)2 is isolated.With trifluoroacetic anhydride as a solvent, ClCF2NClF is dehalogenated with mercury to give excellent yields of CF2=NF in the first practical synthesis of this simplest perfluoro imine.Details of these reactions and the characterization of the new compounds ClCF2NHF, CF3CF2NHF, CF3CF2CF2NHF, and CF3CF2CF=NF are presented.