Abstract
The highly enantioselective organocatalytic construction of spiroindanes containing an all-carbon quaternary stereocenter by intramolecular Friedel-Crafts-type 1,4-addition is described. The reaction was catalyzed by a cinchonidine-based primary amine and accelerated by water and p-bromophenol. A variety of spiro compounds containing quaternary stereocenters were obtained with excellent enantioselectivity (up to 95 % ee). The reaction was applied to the asymmetric formal synthesis of the spirocyclic natural products (-)-cannabispirenones A and B. Art and crafts: Intramolecular Friedel-Crafts-type 1,4-addition under organocatalytic conditions enabled the highly enantioselective construction of spiroindanes containing an all-carbon quaternary stereocenter. The reaction was applied to the asymmetric formal synthesis of the spirocyclic natural products (-)-cannabispirenone A and B (see scheme).
| Original language | English |
|---|---|
| Pages (from-to) | 6734-6738 |
| Number of pages | 5 |
| Journal | Angewandte Chemie - International Edition |
| Volume | 55 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2016 Jun 1 |
Keywords
- asymmetric catalysis
- cyclization
- natural products
- organocatalysis
- spiro compounds
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)