Rh(I)-Catalyzed Ring Opening of an IMDAF-Derived Oxabicyclo Cycloadduct as the Key Step in the Synthesis of (±)-<i>epi</i>-Zephyranthine
作者:Qiu Wang、Albert Padwa
DOI:10.1021/ol049348f
日期:2004.6.1
A new strategy for epi-zephyranthine has been developed that is based in part on an extraordinarily facile intramolecular Diels-Alder reaction of a 2-imido-substituted furan. By using a Rh(I)-catalyzed ring opening of the resulting oxabicyclic adduct, the cis-diol stereochemistry of epi-zephyranthine was established.
Rhodium(I)-Catalyzed Nucleophilic Ring-Opening Reactions of Oxabicyclo Adducts Derived from the [4 + 2]-Cycloaddition of 2-Imido-Substituted Furans
作者:Albert Padwa、Qiu Wang
DOI:10.1021/jo060238r
日期:2006.4.1
the alkenyl π-bond followed by a nitrogen-assisted cleavage of the carbon−oxygen bond occurs to furnish a π-allyl rhodium(III) species. Addition of the nucleophile then occurs from the least hindered terminus of the resulting π-allyl rhodium(III) complex. Proton exchange followed by rhodium(I) decomplexation ultimately leads to the cis-diastereomer.