Advances In Asymmetric Reactions Research Articles

Recent advances in asymmetric reactions catalyzed by chiral phosphoric acids

This review summarizes the very recent advances in asymmetric reactions catalyzed by chiral phosphoric acids (CPAs), a family of versatile catalysts that catalyze a broad range of reactions to afford diverse chiral molecules. In the past years, different kinds of chiral phosphoric acids have been designed and developed into a privileged class of catalysts in asymmetric synthesis. A number of remarkable achievements have been made by many groups around the world. Due to length limitation, this review only summarizes those works published from January 2016 to November 2017. Meanwhile, catalytic systems which combine metal catalysts and chiral phosphoric acids will not be discussed in this review.

Recent Advances in Asymmetric Reactions Catalyzed by Proline and Its Derivatives

Asymmetric reactions are carried out by organocatalysis in many ways, making them very competitive and practical. One remarkable molecule, the amino acid proline, has become a crucial component in organocatalysis because of its ability to promote chemical transformations with high enantioselectivity. The following review discusses the contributions and recent advances in the field of asymmetric reactions catalyzed by l -proline and its derivatives. 1 Introduction 2 Asymmetric Aldol Reactions Catalyzed by Proline and Its Derivatives 2.1 Reactions of Ketones as Aldol Donors with Aldehydes as Aldol Acceptors 2.2 Reactions of Aldehydes as Aldol Donors with Aldehydes as Aldol Acceptors 2.3 Reactions of Aldehydes as Aldol Donors with Active Ketones as Aldol Acceptors 2.4 Reactions of Ketones as Aldol Donors with Active Ketones as Aldol Acceptors 3 Asymmetric Mannich Reactions Catalyzed by Proline and Its Derivatives 4 Asymmetric Michael Reactions Catalyzed by Proline and Its Derivatives 5 Asymmetric α-Amination Reactions Catalyzed by Proline and Its Derivatives 6 Conclusion

Recent Progress in Memory Of Chirality (MOC): An Advanced Chiral Pool

This review describes the recent advances in asymmetric reactions based on memory of chirality. The memory of chirality is a unique concept concerning an advanced type of chiral pool-based asymmetric synthesis, in which reactions take place at the sole stereogenic center of the starting materials. The original sp3 chirality of the starting material is retained as dynamic sp2 chirality in the intermediate, and then transferred to sp3 chirality of the product. These asymmetric reactions were found to proceed through various types of chiral intermediates with dynamic nature. This review describes the phenomena of memory of chirality observed in asymmetric reactions proceeding through radical, cationic, and anionic intermediates. 1 Introduction 2 Memory of Chirality Proceeding through Radical Intermediates 3 Memory of Chirality Proceeding through Cationic Intermediates 4 Memory of Chirality Proceeding through Anionic Intermediates 5 Conclusion

Asymmetric Catalysis with Metal Complexes in Nanoreactors

Recently, the field of heterogeneous asymmetric catalysis, generally using chiral solid catalysts, has attracted much attention in the production of single enantiomers. Among versatile chiral solid catalysts, chiral metal complexes confined in nanoreactors often exhibit very unique enantioselectivity and catalytic activity compared to homogeneous catalysts. In this Focus Review, we summarize the recent advances in asymmetric reactions on chiral metal complexes confined in nanoreactors with an emphasis on the confinement effect and cooperative activation effect of the nanoreactor and new strategies for the preparation of chiral solid catalysts, such as the encapsulation of chiral metal complexes in the nanocages of mesoporous silica and incorporation of chiral ligands in the network of mesoporous organosilicas.