Enamines of Acylsilanes:  Electrochemical Synthesis, Structure, and Use as a Source of α-(Trimethylsilyl)alkylamines

Abstract

R-(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. 29 Si NMR spectroscopic studies allowed the complete assignment of the E and Z structures of these isomeric enamines.

Synthesis and Structure ofN-(Silylalkyl)amides: Rhodium-Catalyzed Hydrosilylation of Enamides

“…Finally, hydrolysis of N -(silylethyl)phthalimide 2f with hydrazine was examined (eq 5) since the general synthetic method of (silylethyl)amine 7 is still lacking …”

Thermolysis of Acylazo O-Trimethylsilyl Cyanohydrins: Azoalkanes Yielding Captodatively Substituted Radicals

“…2-[(Trimethylsilyl)oxy]propanenitrile (7) was prepared from distilled acetaldehyde, trimethylsilyl cyanide, and catalytic Et 3 N in dry CH 2 Cl 2 at 0 °C …”

“…2-[(Trimethylsilyl)oxy]propanenitrile (7) 46 was prepared from distilled acetaldehyde, trimethylsilyl cyanide, and catalytic Et3N in dry CH2Cl2 at 0 °C. 23 1 H NMR (C6D6): 0.00 (9H, s), 1.02 (3H, d, J ) 6.6 Hz), 3.84, (2H, q, J ) 6.6 Hz).…”

Unprecedented use of 29Si NMR spectroscopy for a convenient determination of enantiomeric excesses of chiral α-C-silylated amines and alcohols†

“…3 One of these consisted of the reduction of acylsilane imines obtained via reductive silylation of cyanohydrins. 4 Because of the potential biological interest of these amines and their derivatives, their synthesis in enantiomeric form is of importance. Although the literature provided us with some examples, 5 no synthesis of such chiral primary amines were described before our recent publication.…”