A cascade of styrylynols promoted by MnO2 allows the synthesis of fused tricycles with a naphthalene core. The reaction occurs under ambient conditions, offering a practical synthetic tool because of the inexpensive and abundant manganese species. The method affords products through the sequential oxidation of a propargyl alcohol, stepwise Diels–Alder cyclization, and finally rearomatization. According
Alkene‐Directed
<i>N</i>
‐Attack Chemoselectivity in the Gold‐Catalyzed [2+2+1]‐Annulations of 1,6‐Enynes with
<i>N</i>
‐Hydroxyanilines
作者:Deepak B. Huple、Bhanudas D. Mokar、Rai‐Shung Liu
DOI:10.1002/anie.201507946
日期:2015.12
Kinetically unstable nitrones are generated from gold‐catalyzed reactions of 1,6‐enynes with N‐hydroxyanilines, and subsequently trapped by tethered alkenes to furnish [2+2+1]‐annulations. Our experimental data reveal that such nitrones arise from atypical N‐attackchemoselectivity that is triggered by tethered alkenes to facilitate the key protodeauration reaction.
作者:Barry M. Trost、Eric D. Edstrom、Mary Beth Carter-Petillo
DOI:10.1021/jo00280a006
日期:1989.9
Cycloisomerization of 1,6-enynes in organoaqueous medium: an efficient and eco-friendly access to furan derivatives. Synthesis of a key intermediate of podophyllotoxin
The first cycloisomerization of enynes catalyzed by Pd(TPPTS)(3) catalyst in aqueous medium to give functionalized furans is described. This new reaction has been applied to the synthesis of podophyllotoxin analog. (C) 2001 Elsevier Science Ltd. All rights reserved.