Z-Stereoselective Aza-Peterson Olefinations with Bis(trimethylsilane) Reagents and Sulfinyl Imines
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.
Das, Manas,OShea, Donal F.
supporting information
p. 336 - 339
(2016/02/03)
Palladium-phosphine-complex-catalyzed reaction of organolithium compounds and alkenyl halides: (Z)-β-[2-(N,N-dimethylamino)phenyl]styrene