ELECTROPHILIC AMINATION OF HIGHER-ORDER CUPRATES WITH N,O-BIS(TRIMETHYLSILYL)HYDROXYLAMINE

In the reaction of higher order cyanocuprates with N,O-bis(trimethylsilyl)hydroxylamine delivery of the NHSiMe3 moiety to one of the anionic ligands in the cuprate takes place even in the absence of external bases according to an ''electrophilic amination'' protocol. Details of the methodology are given, and the reaction mechanism is analyzed in terms of interception by a mixed bis-metal cluster of a lithium N-silyl-N-siloxyamide, followed by intramolecular C-N coupling. This method is applicable to cyanocuprates bearing aromatic, heteroaromatic, and saturated aliphatic ligands. A number of 2-amino-substituted heterocycles, not easily accessible by normal routes, can be obtained with the aid of a stabilizing silylation at the nitrogen atom.