Abstract
The asymmetric hetero-Diels-Alder reactions of three Danishefsky"s dienes and two Brassard"s dienes with aldehydes that have been performed in our group are presented. (R )-1,1¢-Bi-2-naphthol [(R )-BINOL] and its derivatives complexed with tetraisopropoxytitanium(IV) [Ti(Oi -Pr)4 ] were efficient catalytic systems for the reactions with Danishefsky"s dienes, proceeding via a Mukaiyama aldol pathway. Meanwhile, tridentate Schiff base ligands complexed with Ti(Oi -Pr)4 or copper(II) triflate [Cu(OTf)2 ] were efficient for the reactions of Brassard’s dienes, following the Diels-Alder pathway.
1 Introduction
2 Asymmetric Hetero-Diels-Alder Reactions of Danishefsky"s and Danishefsky-Type Dienes
2.1 Asymmetric Hetero-Diels-Alder Reactions of Danishefsky"s Diene
2.2 Asymmetric Hetero-Diels-Alder Reactions of a Danishefsky-Type Diene To Give 2,6-Disubstituted Dihydropyrones
2.3 Asymmetric Hetero-Diels-Alder Reactions of a Danishefsky-Type Diene To Give 2,5-Disubstituted Dihydropyrones
3 Asymmetric Hetero-Diels-Alder Reactions of Brassard"s and Brassard-Type Dienes
3.1 Asymmetric Hetero-Diels-Alder Reactions of Brassard"s Diene
3.2 Asymmetric Hetero-Diels-Alder Reactions of a Brassard-Type Diene
4 Summary and Perspectives
Key words
asymmetric catalysis - Diels-Alder reactions - heterocycles - Lewis acids - Schiff bases