Efficient and practical Ag-catalyzed cycloadditions between arylimines and the Danishefsky diene.
An efficient Ag-catalyzed method for asymmetric addition of the Danishefsky diene to various aryl imines to afford cycloadducts in > or =89% ee and > or =85% isolated yield is reported. Reactions are effected with 0.1-1 mol % catalyst (4 degrees C), and the chiral ligand is readily prepared from commercially available materials, including the inexpensive i-Leu. These catalytic asymmetric cycloadditions can be carried out without the use of solvent or with undistilled THF in air. A first generation supported chiral catalyst that effectively promotes the cycloaddition reaction and can be recycled (five cycles) is described.
Josephsohn
Nathan S
NS
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
Snapper
Marc L
ML
Hoveyda
Amir H
AH
D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D010880:Piperidines / Q000138:chemical synthesis*; D012834:Silver / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D007097:Imines; D010880:Piperidines; D012834:Silver