Abstract
A new diastereoselective and enantioselective cyclopropanation reaction has been developed by employing a Michael/alkylation cascade reaction between (E)-3-arylenechroman-4-one or (E)-2-arylideneindan-1-one derivatives and a bromonitroalkane with a chiral squaramide catalyst. This reaction constitutes a facile asymmetric synthesis for nitro-spirocyclopropanes that have three adjacent stereogenic centers, including one quaternary center, in moderate to good yields (up to 90%) with excellent enantio- [up to >99%ee (enantiomeric excess)] and diastereoselectivities [up to >99:1 dr (diastereomeric ratio)]. A cascade cyclopropanation reaction between (E)-3-arylenechroman-4-one or (E)-2-arylideneindan-1-one derivatives and a bromonitroalkane with a chiral squaramide catalyst has been developed. Nitro-spirocyclopropanes were obtained in moderate to good yields (up to 90%) with enantioselectivities up to >99%ee (enantiomeric excess) and diastereoselectivities up to >99:1 dr (diastereomeric ratio).
Original language | English |
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Pages (from-to) | 5350-5359 |
Number of pages | 10 |
Journal | European Journal of Organic Chemistry |
Volume | 2015 |
Issue number | 24 |
DOIs | |
Publication status | Published - 1 Aug 2015 |
Keywords
- Alkylation
- Asymmetric catalysis
- Domino reactions
- Michael addition
- Organocatalysis
- Spiro compounds