Pure Appl. Chem., 2002, Vol. 74, No. 1, pp. 143-149
http://dx.doi.org/10.1351/pac200274010143
Metal-assisted amination with oxime derivatives
Abstract:
Electrophilic amination of Grignard reagents is accomplished
by using O-sulfonyl-oximes of benzophenone derivatives. In the presence
of a catalytic amount of CuCN, O-sulfonyloxime of 4,4¢-bis(trifluoromethyl)benzophenone
reacts with alkyl Grignard reagents in tetrahydrofuran (THF) and hexamethylphosphoramide
(HMPA), yielding primary alkyl-amines by successive hydrolysis of the
resulting N-alkylimines. Arylamines are also prepared as well as alkylamines
by treating O-sulfonyloxime of 3,3¢,5,5¢-tetrakis(trifluoromethyl)benzophenone
in toluene-ether with Grignard reagents.
Various cyclic imines are synthesized by palladium-catalyzed cyclization
of olefinic oxime derivatives. That is, the reaction of O-pentafluorobenzoyloximes
of olefinic ketones with a catalytic amount of Pd(PPh3)4 and triethylamine
in dimethylformamide (DMF) affords nitrogen-containing heterocycles,
such as pyrroles, pyridines, isoquinolines, spiro-imines, and aza-azulenes.
This reaction proceeds via the initial formation of alkylideneaminopalladium
species generated by oxidative addition of oximes to Pd(0), and the
successive intramolecular Heck-type amination occurs on the olefinic
moiety.