Catalytic asymmetricPauson–Khandreactions with chiral bidentate phosphines as ligands have been successfully accomplished. The catalytic use of (S)-BINAP as a ligand was demonstrated to be the most effective in the cobalt-catalyzed reactions of 1,6-enynes, providing a facile entry to optically active 2-cyclopentenone derivatives with high enantioselectivity. A plausible mechanism for the asymmetric induction
A cobalt-catalyzed reaction of 1,6-enyne systems under a carbon monoxide atmosphere using chiral phosphine ligands provides a facile entry to optically active 2-cyclopentenone derivatives. (S)-BINAP was demonstrated to be the most effective in the cobalt-catalyzed cyclization of 1,6-enynes among various chiral bidentate phosphine ligands employed, affording chiral 2-cyclopentenone derivatives with
An Efficient Gold-Catalyzed Domino Process for the Construction of Tetracyclic Ketoethers
作者:Tobias Groß、Peter Metz
DOI:10.1002/chem.201302985
日期:2013.10.25
Au, yeah! Catalytic amounts of gold(III)chloride allow a mild and efficient oxidative domino cyclization/cycloaddition of enyne carbonyl compounds 1 and 4 to give the tetracycles 2 or 5, respectively, in the presence of pyridine N‐oxide 3 (see scheme; DCE = 1,2‐dichloroethane).
Hydrogenative Cycloisomerization and Sigmatropic Rearrangement Reactions of Cationic Ruthenium Carbenes Formed by Catalytic Alkyne
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‐Hydrogenation
作者:Tobias Biberger、Stephan N. Hess、Markus Leutzsch、Alois Fürstner
DOI:10.1002/anie.202113827
日期:2022.2.14
unprecedented hydrogenation reactions are disclosed, commencing with geminal delivery of both H-atoms of H2 to the triple bond of a propargyl alcohol derivative. When catalyzed with cationicrutheniumcomplexes, the resulting pianostool carbenes are so “hot” that they are readily intercepted by tethered nucleophiles, resulting in cycloisomerization or [2,3]-sigmatropic rearrangement reactions.
Stereospecific 1,4-addition reaction of sulfinylallyl anion: Synthesis of (±)-pentalenolactone e methyl ester
作者:Duy H. Hua、M.Jo Coulter、Ibraheem Badejo
DOI:10.1016/s0040-4039(00)96755-8
日期:1987.1
Stereospecific 1,4-Addition reaction of lithiated sulfinylallyl anion and enone 2 provided the corresponding 1,4-γ-adduct, 7. In seven steps, 7 was converted into octahydro-2-methoxy-8,8-dimethylpentalenol[1,6a-c]pyran-5-(6)-one (9) whose conversion into pentalenolactone E methyl ester (1) has been previously reported.