The Preparation of 1,1-Di-H-Heptafluorobutyl Iodide and 1,1-Di-H-Heptafluorobutyl Bromide and Their Intermediates

Abstract

Three distinct methods of preparation of 1, l-di-//-perfluoroalkyl halides have been developed in this laboratory. We wish to report a brief account of two of these methods along with the chemistry of some of the intermediates. The third method has been published (1).The first 1, l-di-JT-heptafluorobutyl halide ever prepared was 1,1-di-JTheptafiuorobutyl iodide. 1, l-Di-H-heptafiuorobutyl amine, C3F7CH2NH2, was reacted with nitrous acid in aqueous solution to give 1-17-hep tafiuorodiazobutane, C3F7CHN2, which was isolated by distillation in one run. Treatment of 1-7/heptafluorodiazobutane with an excess of hydrogen iodide in 3, d'-dichlorodiethyi ether at room temperature gave 1, l-di-H-heptafluorobutyl iodide, C3F7CH2L No reaction occurred at Dry Ice temperature, -78°.

Polyfluorinated Ethanes as Versatile Fluorinated C2-Building Blocks for Organic Synthesis

“…The subsequent reaction with halides opens a simple laboratory approach to trifluoromethylated halomethanes . CF 3 CH 2 I has also been prepared from phosphate 5 by reaction with sodium iodide . Another laboratory synthesis of CF 3 CH 2 I is based on the transformation of trifluoroethanol into trimethylsilyl ether 6 followed by reaction with Ph 3 PICl to form target compound in 36% yield (Scheme ) .…”

Fluorinated phosphorus compounds

“…These were isolated in 60-70% yield by heating the respective fluoroalcohol with phosphorus trichloride in a 3:1 molar ratio, according to the method of Krogh et al [14]. Boiling points for phosphites 9, 10 and 11 were 43 8C/ 10 mmHg, 38 8C/2 mmHg and 96 8C/16 mmHg, respectively.…”

The palladium-catalyzed cross-coupling reactions of trifluoroethyl iodide with aryl and heteroaryl boronic acid esters

“…10,11 During the past decades, the palladium catalyzed crosscoupling reaction of organic halides with organometallic compounds has greatly progressed. Although trifluoroethyl iodide is commercially available, 12 the palladium catalyzed reaction of trifluoroethyl iodide with organometallic compounds still remains difficult. The reluctance of inactivated trifluoroethyl iodide to oxidatively add to palladium(0) and the pronounced tendency of alkyl-palladium complexes to undergo elimination of b-fluoride ions of trifluoroethyl-metals are generally believed to be equally responsible for the difficulty in performing such reactions.…”