Stereoselective Peterson Olefinations from Bench‐Stable Reagents and N ‐Phenyl Imines

The synthesis of bench‐stable α,α‐bis(trimethylsilyl)toluenes and tris(trimethylsilyl)methane is described and their use in stereoselective Peterson olefinations has been achieved with a wide substrate scope. Product stereoselectivity was poor with carbonyl electrophiles ( E / Z ∼1:1 to 4:1) though this was significantly improved by employing the corresponding substituted N ‐benzylideneaniline (up to 99:1) as an alternative electrophile. The olefination byproduct was identified as N , N ‐bis(trimethylsilyl)aniline and could be easily separated from product by aqueous acid extraction. Evidence for an autocatalytic cycle has been obtained.