Synthesis and organocatalytical evaluation of optically pure inherently chiral calix[4]arene phosphoric acids
Résumé
Two pairs of diastereomerically pure calix[4]arene phosphoric acid derivatives with ABHH and ABCH substitution patterns were synthesized via phosphorylation and phosphotropic rearrangement on the narrow rim. These new cone-shaped, inherently chiral calixarenes were tested as organocatalysts in the stereoselective aza-Diels–Alder reaction of imines with Danishefsky's diene, as well as in the stereoselective epoxide ring opening.