title: Z-Stereoselective Aza-Peterson Olefinations with Bis(trimethylsilane) Reagents and Sulfinyl Imines.
abstract: Highly stereoselective aza-Peterson olefinations from bench-stable α,α-bis(trimethylsilyl)toluene reagents and N-substituted imines have been achieved using TMSO(-)/Bu4N(+) as Lewis base activator in THF. Remarkably, and for the first time, N-t-butanesulfinyl imines were utilized for the synthesis of Z-stilbenes with excellent selectivities, while N-aryl imines generated E-stilbenes under identical reaction conditions. The protocol proved general for numerous examples with low molecular weight byproducts formed. The origin of the Z-selectivity is proposed to be a result of diastereoselective addition to N-t-butanesulfinyl imines followed by syn-elimination of an in situ formed hypervalent silicate.
authors.affiliation: Department of Pharmaceutical and Medicinal Chemistry, Royal College of Surgeons in Ireland , 123 St. Stephen's Green, Dublin 2, Ireland.
authors.forename: Manas
authors.initials: M
authors.lastname: Das
authors.affiliation: Department of Pharmaceutical and Medicinal Chemistry, Royal College of Surgeons in Ireland , 123 St. Stephen's Green, Dublin 2, Ireland.
authors.forename: Donal F
authors.initials: DF
authors.lastname: O'Shea
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D007202:Indicators and Reagents; D015394:Molecular Structure; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D000475:Alkenes; D007097:Imines; D007202:Indicators and Reagents; D012821:Silanes; D013454:Sulfoxides