Synfacts 2006(4): 0358-0358  
DOI: 10.1055/s-2006-932044
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Cr(III)-Porphyrin-Catalyzed Enantioselective Hetero-Diels-Alder Reactions

Contributor(s): Mark Lautens, Andrew Martins
A. Berkessel*, E. Ertürk, C. Laporte
Universität zu Köln, Germany
Further Information

Publication History

Publication Date:
24 March 2006 (online)

Significance

Using a chiral Cr(III)-porphyrin catalyst, a variety of aldehydes were coupled with Danishefsky’s diene and several other dienes to form pyran-based heterocycles. Yields and enantioselectivities were generally good to excellent with Danishefsky’s diene; however, poorer results were obtained with less electron-rich dienes. The reaction with 2-pyridylcarbaldehyde is the first known example of a Cr-catalyzed hetero-Diels-Alder (HDA) reaction with pyridyl substrates.