Fluorinated Organocopper Reagents

Abstract

Introduction Fluoroalkenylcopper Reagents Difluorovinylcopper Reagents Perfluoroallylcopper Reagents Perfluoroalkynylcopper Reagents Carboalkoxydifluoromethylenecopper Reagents Dialkoxyphosphinylfluoromethylcopper Reagent Dialkoxyphosphinyldifluoromethylcopper Reagents Perfluorobenzylcopper Reagent Perfluoroalkylcopper Reagents Pentafluorophenylcopper Reagent 2,3,5,6‐Tetrafluoropyridylcopper Reagents

Aromatic Trifluoromethylation with Metal Complexes

“…As discussed in detail in recent monographs, − perfluoroalkyl groups, CF 3 included, form strong and usually poorly reactive bonds to carbon atoms in organic molecules. On the other hand, the stability of metal perfluoroalkyls strongly depends on the nature of both the R f and the metal, as described and analyzed in a number of reviews on perfluoroalkyl derivatives of both the main group elements ,,, and the transition metals. ,,− In general, the M−R f bonds are considerably stronger and much less reactive than those of the conventional, nonfluorinated metal alkyls. Hughes writes: “It is now well accepted that compounds containing metal-perfluoroalkyl (M−R f ) bonds are in some ways less reactive and are invariably more thermally stable than analogues containing hydrocarbon alkyl (M−R) linkages.” Although in most instances the metal−carbon bond is shorter for M−CF 3 than for the analogous M−CH 3 species, this is not always the case. , The C−F bonds in metal trifluoromethyls are usually longer and weaker than in organic CF 3 derivatives.…”

“…There are many methods to synthesize metal perfluoroalkyls. ,,,,,,− These include Klabunde’s metal atom condensation with perfluoroalkyl halides and reactions of various metal species with CF 3 radicals generated from the glow discharge of C 2 F 6 , developed by Lagow . These methods require special equipment and have been reviewed, so they will not be considered herein.…”

“…As early as 1928, Lehmann reported his observations of biological activity of some trifluoromethylated organic derivatives and already in 1959 Yale published a detailed review article entitled “The Trifluoromethyl Group in Medicinal Chemistry”. Since then, numerous books and reviews have appeared in the literature covering various aspects of trifluoromethylated organic − and organometallic ,,,, compounds. Within this family, derivatives bearing the CF 3 group on aromatic rings are particularly numerous and important.…”

“…Since the late 1960s, the area of aromatic trifluoromethylation with metals has been continuously growing. Results of these studies by numerous research groups have been described in a number of surveys, including the particularly in-depth review articles by Burton and Yang (1992), McClinton and McClinton (1992), Burton and Lu (1997), and more recently by Schlosser (2006), Davis and Burton (2009), and Kumadaki’s group (2010) . A recent brief essay on the subject by Fors is available online.…”