Synthesis 2014; 46(02): 135-157
DOI: 10.1055/s-0033-1338581
review
© Georg Thieme Verlag Stuttgart · New York

Catalytic Asymmetric Aza-Diels–Alder Reactions: The Povarov Cycloaddition Reaction

Mariafrancesca Fochi*
Department of Industrial Chemistry ‘Toso Montanari’, Alma Mater Studiorum – University of Bologna, V. Risorgimento 4, 40136 Bologna, Italy   Fax: +39(051)2093639   Email: mariafrancesca.fochi@unibo.it   Email: luca.bernardi2@unibo.it
,
Lorenzo Caruana
Department of Industrial Chemistry ‘Toso Montanari’, Alma Mater Studiorum – University of Bologna, V. Risorgimento 4, 40136 Bologna, Italy   Fax: +39(051)2093639   Email: mariafrancesca.fochi@unibo.it   Email: luca.bernardi2@unibo.it
,
Luca Bernardi*
Department of Industrial Chemistry ‘Toso Montanari’, Alma Mater Studiorum – University of Bologna, V. Risorgimento 4, 40136 Bologna, Italy   Fax: +39(051)2093639   Email: mariafrancesca.fochi@unibo.it   Email: luca.bernardi2@unibo.it
› Author Affiliations
Further Information

Publication History

Received: 01 August 2013

Accepted after revision: 06 September 2013

Publication Date:
10 December 2013 (online)


Abstract

The Povarov reaction provides a straightforward and modular entry to 1,2,3,4-tetrahydroquinolines (THQs). Despite its importance, it was only very recently that several highly efficient catalytic asymmetric protocols for this reaction have been developed, as summarized in this review which falls on the 50th anniversary of Povarov’s pioneering disclosure. Furthermore, this review collects and critically discusses the interrupted versions of the reaction, often featuring intriguing and still unclear mechanicistic pathways.

1 Introduction

2 Catalytic Asymmetric Povarov Cycloaddition Reactions

2.1 Chiral Lewis Acid Catalysis

2.2 Chiral Brønsted Acid Catalysis

2.2.1 Chiral Phosphoric Acid Catalyzed Povarov Cycloaddition Reactions

2.2.2 Chiral Urea Catalyzed Povarov Cycloaddition Reactions

3 Catalytic Asymmetric Interrupted Povarov Reactions

3.1 Intermolecularly Interrupted Povarov Reactions

3.2 Intramolecularly Interrupted Povarov Reactions

3.2.1 Interrupted Povarov Reactions with Salicyaldehyde-Derived Imines

3.2.2 Interrupted Povarov Reactions with Glyoxylic Acid Derived Imines

4 Conclusion