Rhodium(III)-Catalyzed Dearomatizing (3 + 2) Annulation of 2-Alkenylphenols and Alkynes
摘要:
Appropriately substituted 2-alkenylphenols undergo a mild formal [3C+2C] cycloaddition with alkynes when treated with a Rh(III) catalyst and an oxidant. The reaction, which involves the cleavage of the terminal C-H bond of the alkenyl moiety and the dearomatization of the phenol ring, provides a versatile and efficient approach to highly appealing spirocyclic skeletons and occurs with high selectivity.
Rhodium-Catalyzed (5+1) Annulations Between 2-Alkenylphenols and Allenes: A Practical Entry to 2,2-Disubstituted 2<i>H</i>-Chromenes
作者:Noelia Casanova、Andrés Seoane、José L. Mascareñas、Moisés Gulías
DOI:10.1002/anie.201410350
日期:2015.2.16
alkenylphenols react with allenes under rhodiumcatalysis to provide valuable 2,2‐disubstituted 2H‐chromenes. The whole process, which involves the cleavage of one CH bond of the alkenyl moiety and the participation of the allene as a one‐carboncycloaddition partner, can be considered a simple, versatile, and atom‐economical (5+1) heteroannulation. The reaction tolerates a broad range of substituents