Abstract
The development of chiral borane Lewis acid catalysts opened the door for transition-metal-free catalyzed asymmetric organic reactions. Herein, we have summarized our work on the preparation of two classes of novel chiral bicyclic bisborane Lewis acid catalysts derived from C
2-symmetric [3.3.0] dienes and [4.4] dienes, respectively. These catalysts not only form frustrated Lewis pairs with Lewis bases to catalyze asymmetric hydrogenation reactions but also activate Lewis basic functional groups in traditional Lewis acid catalyzed asymmetric reactions.
1 Introduction
2 Synthesis of C
2-Symmetric Fused Bicyclic Bisborane Catalysts and Their Use in Imine Hydrogenation
3 Synthesis of Spiro Bicyclic Bisborane Catalysts and Their Use in N-Heteroarene Reduction
4 Other Types of Asymmetric Reactions Promoted by Chiral Bicyclic Bisborane Catalysts
5 Conclusion
Key words
chiral borane - Lewis acid - frustrated Lewis pair - asymmetric catalysis -
C
2-symmetric - hydrogenation