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
Synthesis of 2-Cyclopentenones by Gold(I)-Catalyzed Rautenstrauch Rearrangement
作者:Xiaodong Shi、David J. Gorin、F. Dean Toste
DOI:10.1021/ja051689g
日期:2005.4.1
cyclopentenones catalyzed by cationic triphenylphosphinegold(I) complexes is described. The reaction tolerates both alkyl and aryl substitution at the acetylenic and olefinic positions. Importantly, the gold(I)-catalyzed rearrangement of enantioenriched propargyl pivaloates proceeds with excellent chirality transfer, thus providing a practical method for the enantioselective synthesis of cyclopentenones.