First Diels-Alder Reactions of Enantiomerically Pure 1-p-Tolylsulfinyl Dienes: Straightforward Access to Cyclohexenols through Tandem Cycloaddition/[2,3]-Sigmatropic Rearrangement

Asymmetric [4+2] Cycloadditions Mediated by Sulfoxides

“…The first involved the expected intermolecular Diels-Alder reaction, which must be completely stereoselective, exhibiting a similar course to that previously postulated for the reaction of 161A and NMM [142] and depicted in Fig. 15.…”

“…Asymmetric Diels-Alder reactions of 1-p-tolylsulfinyldienes 161 with N-methylmaleimide (NMM) were completely stereoselective both under thermal and catalyzed conditions [142], yielding the same compounds endo-162 as sole adducts. The reactivity of the diene is very low, even in the presence of Lewis acids acting as catalysts (more than 20 days are required for these reactions to complete), and the p-facial selectivity is completely controlled by the sulfinyl group.…”

Selectivity Controls in the [4+2] Cycloadditions of 1-Oxygenated Dienes

“…75 A model TS minimizing the steric and electronic interactions was proposed to explain the sense of the induction. Depending on the experimental conditions, the primary product was or was not isolated: it undergoes a spontaneous and stereospecific [2,3]-sigmatropic rearrangement resulting in a single isomer of a functionalized tetrahydroisoindanedione.…”

Novel Stereoselective Synthesis of 1,3-Dien-2-yl Esters by a Palladium-Catalysed Cross-Coupling Reaction of (E)-α-iodo-α,β-Unsaturated Esters

“…The stereoselective synthesis of conjugated dienes has attracted considerable interest in organic chemistry because of their appearance in a wide variety of biologically active molecules and because they are key synthetic intermediates. 1,2 The synthesis of 1,3-dienes for use in the Diels-Alder reaction is still an important challenge in organic synthesis 3 although other elegant uses of these compounds have been developed. 4 The transition metal-catalysed cross-coupling reactions of stereodefined vinyl halides with vinyl organometallic compounds have provided a straightforward and convenient route for the stereocontrolled synthesis of conjugated dienes.…”