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

• Published in: Chemistry : a European journal Vol. 21; no. 24; pp. 8737 - 8740
• Main Authors: Das, Manas, Manvar, Atul, Jacolot, Maïwenn, Blangetti, Marco, Jones, Roderick C., O'Shea, Donal F.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 08.06.2015; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: Alkenes - chemical synthesis; bench-stable reagents; Byproducts; Carbonyl compounds; Carbonyls; Chemical Sciences; Chemistry; Chemistry, Multidisciplinary; Extraction; Imines; Imines - chemistry; Molecular Structure; Organic chemistry; organic synthesis; Peterson olefination; Physical Sciences; Reagents; Science & Technology; Stereoisomerism; Stereoselectivity; Synthesis; VINYL SILANES; METALATION; MECHANISM; SILICON; imines; CARBONYL-COMPOUNDS; CARBANIONS; bench-stable reagents; Peterson olefination; ALKENES; stereoselectivity; organic synthesis; FLUORIDE-ION; ABSENCE; DERIVATIVES
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.201500475

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. A mild method for E‐selective Peterson olefinations is described. Bench‐stable α,α‐bis(trimethylsilyl)toluenes and tris(trimethylsilyl)methane are used as reagents in reaction with substituted N‐phenyl imines (see scheme).