Enantio- and Regioselective Conjugate Addition of Organometallic Reagents to Linear Polyconjugated Nitroolefins
作者:Matthieu Tissot、Alexandre Alexakis
DOI:10.1002/chem.201300538
日期:2013.8.19
The copper‐catalysed conjugate addition of trialkylaluminium and dialkylzinc reagents to polyconjugated nitroolefins (nitrodiene and nitroenyne derivatives) is reported. A reversed Josiphos ligand L7 allows for the selective 1,4‐ or 1,6‐addition with high enantioselectivities.
Mild conversion of propargylic alcohols to α,β-unsaturated enones in ionic liquids (ILs); a new ‘metal free’ life for the Rupe rearrangement
作者:Ganesh C. Nandi、Benjamin M. Rathman、Kenneth K. Laali
DOI:10.1016/j.tetlet.2013.09.028
日期:2013.11
free protocol for the conversion of propargylic alcohols to cyclic and acyclic α,β-unsaturated enones via the Rupe rearrangement is reported. The method utilizes the Brønsted acidic ionic liquid [BMIM-SO3H][OTf] as catalyst and [BMIM][PF6] as solvent and offers the potential for recycling and reuse of the IL solvent. The feasibility to synthesize bicyclic fused cyclopentenone derivatives via a Rupe → Aldol → Nazarov
Cross-couplingreactions between α,β-unsaturated carbonyl compounds and aromatic aldehydes have been achieved in tetrahydrofuran (THF) at 25 °C under N2 using a catalytic amount of InCl3 (0.05 molar amount to the substrate) in the presence of both chlorotrimethylsilane (TMSCl) and aluminum foil (Al). These reactions provide the corresponding β,γ-unsaturated ketones in moderate yields, together with
Five new bulky moiety-modified analogues of the sandalwood odorant Polysantol® have been synthesized by aldol condensation of appropriate aldehydes with butanone, deconjugative α-methylation of the resulting α,β-unsaturated ketones, and reduction of the corresponding β,γ-unsaturated ketones. The final compounds were evaluated organoleptically and one of them seemed to be of special interest for its natural sandalwood scent.
to representative classes of carbon electrophiles (i.e., vinyl sulfones, nitroolefins, formaldehyde) is documented. We demonstrate that by using selected chiral tertiary amine/squaramide catalysts, the reactions of β,γ‐unsaturated cycloalkanones proceed through the dienolate Cα almost exclusively and provide all‐carbon quaternary cyclic ketone adducts in good yields with very high enantioselectivities