Description:
<jats:title>Abstract</jats:title><jats:p>An efficient, highly regio‐ and enantioselective methodology for the synthesis of α‐silyl aldehydes and ketones <jats:bold>2</jats:bold> and <jats:bold>6</jats:bold> using two different procedures was developed. Direct α‐silylation of the azaenolates derived from SAMP/RAMP hydrazones <jats:bold>3</jats:bold> with various silyl trifluoromethanesulfonates resulted after oxidative removal of the chiral auxiliary in highly enantiomerically enriched α‐silyl aldehydes and ketones (<jats:italic>R</jats:italic>)‐ or (<jats:italic>S</jats:italic>)‐<jats:bold>2</jats:bold>. Alternatively, hydrazones <jats:bold>5</jats:bold> derived from acetaldehyde or methyl ketones were initially α‐silylated followed by highly diastereoselective α‐alkylation with suitable electrophiles. The latter variant allows the regiocontrolled synthesis of α‐silyl ketones (<jats:italic>S</jats:italic>)‐<jats:bold>6</jats:bold> with high enantiomeric purity, not available by direct α‐silylation of unsymmetrical ketone hydrazones. The absolute configuration of the resultant α‐silylcarbonyl compounds <jats:bold>2</jats:bold> and <jats:bold>6</jats:bold> was derived from earlier mechanistic investigations of electrophilic substitutions via deprotonated SAMP/RAMP hydrazones and was unambiguously assigned by X‐ray‐crystallographical analysis of the α‐silyl‐SAMP hydrazone (<jats:italic>S,R</jats:italic>)‐<jats:bold>4c</jats:bold>.</jats:p>