Enamines of acylsilanes: Electrochemical synthesis, structure, and use as a source of alpha-(trimethylsilyl)alkylamines

alpha-(Trimethylsilyl)alkylamines (''RSMA''), 1, have been prepared with good yields from enamines of acylsilanes, 2, through reduction of the corresponding iminium salts, 5, with sodium borohydride. The entire process constitutes an original way to homologate a carbonyl compound into the next RSMA, as the starting enamine was obtained through reductive silylation of the O-silyl-protected cyanohydrin, 3, of this carbonyl compound. In this occasion, the electrochemical procedure for the reductive silylation was proven to be as effective as the chemical one, giving 2 in yields of the same order of magnitude, Si-29 NMR spectroscopic studies allowed the complete assignment of the E and Z structures of these isomeric enamines.