User-friendly stereoselective one-pot access to 1,4-diazepane derivatives by a cyclodehydrative three-component reaction with 1,3-dicarbonyls

The Application of 4Å Molecular Sieves in Organic Chemical Syntheses: An Overview

In the last two decades, considerable attention has been devoted to the use of 4Å molecular sieves (MS 4A) in organic chemical syntheses. Initially, they were applied as drying agents in order to dry gases, solvents and liquid reagents. Nowadays, there is a growing tendency to apply MS 4A as an additive, catalyst, co-catalyst or catalyst support in organic reactions. In this review, we aim to summarize the recent examples of organic syntheses promoted by MS 4A from 1997 to 2020. We hope to provide the reader with an overview of the potential of MS 4A in the field of organic synthesis.

1 Introduction

2 Application as an Additive

3 Application as Catalyst

4 Application as Co-catalyst

5 Application as Support

6 Conclusion

One-pot three-component regioselective synthesis of C1-functionalised 3-arylbenzo[f]quinoline

An efficient method for regioselective synthesis of C1-functionalised 3-arylbenzo[f]quinoline has been demonstrated using β-ketoester, 2-naphthylamine and aromatic aldehyde by employing camphorsulfonic acid as the catalyst in acetonitrile at 70 °C.

Highly diastereo- and enantioselective organocatalytic michael addition of α-ketoamides to nitroalkenes

The first organocatalytic enantio- and diastereoselective conjugate addition of α-ketoamides to nitroalkenes has been achieved using a bifunctional amino thiourea catalyst. In this new approach, the substrate amide proton plays a critical role in the formation of the Michael anti-adducts in high yields and high stereoselectivities. To illustrate the high synthetic potential of this methodology, the diastereo- and enantioselective synthesis of a hexasubstituted cyclohexane via a Michael-Michael-Henry cascade reaction is described.