105486-53-1Relevant academic research and scientific papers
γ-Silylated α,ss-unsaturated amides - Preparation by [1,5]-sigmatropic rearrangement and use as masked dienolate equivalents in carbonyl condensations
Green, James R.,Alo, Babajide I.,Majewski, Marek,Snieckus, Victor
experimental part, p. 745 - 759 (2009/12/04)
The reaction of lithium dienolates derived from N,N-dialkylsenecioamides (1a-1c) with triorganosilyl electrophiles occurs initially at the oxygen atom predominantly, and is followed by an O → C silicon migration to afford the γ-silylated senecioamides (4a-4h). The γ-silylated senecioamide Z-4a undergoes fluoride-ion-mediated condensations with aromatic aldehydes to give kinetic α-(6) and thermodynamic γ-(5) condensation product patterns comparable to lithium dienolates. The TiCl4-mediated reactions with aldehydes gives a-products (6) in a highly syn-selective manner. Possible transitionstate models for the syn-selective condensations are discussed and a chair-like transition state featuring bidentate coordination to titanium (11) is proposed.
γ-SILYLATED α,β-UNSATURATED AMIDES. FORMATION BY SILICON MIGRATION FROM O-SILYLATED VINYL KETENE AMINALS AND FLUORIDE- AND LEWIS ACID-MEDIATED ALDOL CONDENSATIONS
Green, J. R.,Majewski, M.,Alo, B. I.,Snieckus, V.
, p. 535 - 538 (2007/10/02)
O-Silylated vinyl ketene aminal 2, obtained from lithiated unsaturated amide 1, undergoes a thermal silicon migration to give γ-silylated product 3b which participates in fluoride- and titanium tetrachloride-mediated aldol condensations to give addu
