A Versatile Enantioselective Catalytic Cyclopropanation‐Rearrangement Approach to the Divergent Construction of Chiral Spiroaminals and Fused Bicyclic Acetals
A highly enantioselective synthesis of various chiral heterobicyclic molecules including spiroaminals and fused bicyclic acetals has been developed via a chiral copper catalyzed cyclopropanation‐rearrangement (CP‐RA) approach under mild reaction conditions. Remarkably, the asymmetric CP‐RA for exocyclic vinyl substrates without a pro‐stereogenic carbon at the β‐position has been realized for the first
Copper-Catalyzed Intramolecular <i>N</i>-Vinylation of Sulfonamides: General and Efficient Synthesis of Heterocyclic Enamines and Macrolactams
作者:Hongjian Lu、Xinting Yuan、Shana Zhu、Changhui Sun、Chaozhong Li
DOI:10.1021/jo8016617
日期:2008.11.7
the catalysis of CuI/N,N'-dimethylethylenediamine, intramolecular C-N coupling between sulfonamides and vinyl halides was successfully implemented, leading to the efficient synthesis of 5-, 6-, 7-, and even 8-membered heterocyclic enamines in both exo and endo modes. The bicyclic enamines thus formed provided a convenient entry to the corresponding 9- to 12-membered lactams by oxidative C=C bond cleavage