Enantioselective epoxide ring opening catalyzed by bis(tetrahydroisoquinoline) N,N'-dioxides

Abstract

Four bis(tetrahydroisoquinoline) N,N'-dioxides were used as catalysts for the epoxide ring opening with tetrachlorosilane under various conditions. A strong solvent effect on asymmetric induction was observed for each of the used catalysts.

The highest achieved asymmetric induction for the opening of meso-stilbene oxide was 69% ee. Regarding the cycloalkene oxides, 56% ee was obtained in the reaction with cyclooctene oxide.

Keywords

• atropoisomeric bipyridine N
• N'-dioxides
• pyridine N-oxides
• chiral lewis-base
• asymmetric allylation
• silicon tetrachloride
• meso-epoxides
• aldehydes
• silanes