Abstract
A bifunctional squaramide-catalyzed Michael/Michael cascade reaction for the construction of spirotetrahydrofuran bispirooxindoles was developed. The products were obtained in moderate to excellent yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, >99% ee). This straightforward process serves as a powerful method for the enantioselective construction of potentially bioactive bispirooxindoles in which two of the four contiguous chiral centers are spiro all-carbon quaternary centers on a single tetrahydrofuran ring. Meanwhile, the synthetic practicality of this methodology was illustrated by performing the reaction on a gram-scale with the same efficiency and stereoselectivity. (Figure presented.).
Original language | English |
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Pages (from-to) | 3992-3998 |
Number of pages | 7 |
Journal | Advanced Synthesis and Catalysis |
Volume | 358 |
Issue number | 24 |
DOIs | |
Publication status | Published - 22 Dec 2016 |
Keywords
- Michael addition
- asymmetric catalysis
- organocatalysis
- spirooxindoles
- squaramides