110770-73-5Relevant academic research and scientific papers
Aprotic Conjugate Addition of Allyllithium Reagents Bearing Polar Groups to Cyclic Enones. 1. 3-Alkylallyl Systems
Binns, Malcolm R.,Haynes, Richard K.,Katsifis, Andrew G.,Schober, Paul A.,Vonwiller, Simone C.
, p. 5411 - 5423 (2007/10/02)
The conjugate addition of lithiated (E)- and (Z)-oct-2-enyl sulfoxides and phosphine oxides, but-2-enyl sulfoxides, phosphine oxides and phosphonates, and 3,3-dimethylallyl and allyl sulfoxides to cyclic enones has been examined.The E and Z carbanions react in highly diastereoselective fashion with five-membered cyclic enones to deliver respectively syn and anti vinylic sulfoxides, phosphine oxides, and phosphonates.Hexamethylphosphoric triamide has no regiochemical influence on these reactions.The regiochemical and stereochemical outcomes of these reactions are rationalized in terms of planar lithiated reagents in which Li+ is bound to oxygen attached to sulfur or phosphorus of the polar group and a 10-membered "trans-decalyl"- or "trans-fused chair-chair"-like transition-state model in which the lithiated reagent adopts an endo orientation over one face of the enone such that for the reagent, the 3-alkyl group is pseudoequatorial, and for the Z, pseudoaxial.
Formation and X-Ray Structural Determination of a Diadduct Obtained from (E)-1-(Phenylsulfinyl)oct-2-enyllithium and 4-t-butoxycyclopent-2-2en-1-one via an Unusual Dianionic Intermediate
Binns, Malcolm R.,Haynes, Richard K.,Katsifis, Andrew G.,White, Allan H.
, p. 291 - 301 (2007/10/02)
As well as the normal vinylic sulfoxides arising by conjugate addition of each of (E)- and (Z)-1-(phenylsulfinyl)oct-2-enyllithium to 4-t-butoxycyclopent-2-en-1-one, small amounts of diadducts are also formed whenever excess lithium N,N-diisopropylamide is used to generate the octenyllithium reagents.The diadducts arise by deprotonation of the vinylic sulfoxide unit within the enolate produced in the initial conjugate addition step followed by the selective reaction of the resultant dianion with another molecules of the enone through the vinylic site.The yield of thediadduct from the carbanion of the (E)-sulfoxide can be increased dramatically through consecutive treatment of the enolate with one equivalent of butyllithium and one equivalent of the enone.The relative configuration of the diadduct from the (E)-carbanion has been established by an X-ray crystallographic study.The conformational preference of the cyclopentanone ring and the attached substituents in the diadduct is briefly discussed in the light of 400-MHz 1H n.m.r. spectroscopic and the X-ray data.
THE DIASTEREOSPECIFIC APROTIC CONJUGATE ADDITION REACTIONS OF CARBANIONS DERIVED FROM ALLYLIC SULFOXIDES AND ALLYLIC PHOSPHINE OXIDES.
Binns, Malcolm R.,Haynes, Richard K.,Katsifis, Andrew A.,Schober, Paul A.,Vonwiller, Simone C.
, p. 1565 - 1568 (2007/10/02)
The title carbanions undergo conjugate addition to cyclic enones in THF to deliver vinylic sulfoxides and vinylic phosphine oxides as single diastereomers.
