Trifluoromethylboranes and -borates: new synthetic strategies and applications.
The synthesis of salts with the [B(CF(3))(4)](-) anion has been the starting point for new developments in the field of trifluoromethylboron chemistry. In contrast to the previous syntheses of (CF(3))(n)B derivatives (n=1-3), achieved exclusively by CF(3) transfer, the synthesis of the [B(CF(3))(4)](-) anion was accomplished by fluorination of the [B(CN)(4)](-) anion with ClF or ClF(3) in anhydrous HF. Owing to its thermal and chemical stability, [B(CF(3))(4)](-) is an attractive weakly coordinating anion. However, in concentrated sulfuric acid one of the four CF(3) groups is solvolyzed to a CO ligand to yield the neutral borane carbonyl (CF(3))(3)BC[triple bond]O. It has been shown that the borane carbonyl compound is a versatile synthetic building block, and numerous reactions have been investigated. The addition of nucleophiles to the C atom of the CO ligand is favored, and examples for new derivatives are the anions [(CF(3))(3)BC[triple bond]Pnic](-) (Pnic=N, P, As). Under certain conditions, ligand-exchange reactions are also observed, for example, the formation of (CF(3))(3)BN[triple bond]CH. Finally, the borane carbonyl compound is a component of the conjugated Brønsted-Lewis superacid HF/(CF(3))(3)BCO.
Finze
Maik
M
Institut für Anorganische Chemie und Strukturchemie II, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany. maik.finze@uni-duesseldorf.de
Bernhardt
Eduard
E
Willner
Helge
H
D000438:Alcohols / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D000641:Ammonia / Q000737:chemistry; D001880:Boranes / Q000138:chemical synthesis* / Q000737:chemistry; D001881:Borates / Q000138:chemical synthesis* / Q000737:chemistry; D001895:Boron / Q000737:chemistry; D018011:Chalcogens / Q000737:chemistry; D006858:Hydrofluoric Acid / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry
D000438:Alcohols; D000588:Amines; D001880:Boranes; D001881:Borates; D018011:Chalcogens; D007659:Ketones; D010720:Phosphines; D000641:Ammonia; C044646:phosphine; D001895:Boron; D006858:Hydrofluoric Acid