Concave Reagents - 14. Concave Pyridines with a 2,6-Diarylpyridine Core.

Article abstract of DOI:10.1016/S0040-4039(00)60676-7

A new type of concave pyridine 4 based on a 2,6-diarylpyridine system is described.By cyclization of a C5-unit 5 or 6 with ammonium acetate a tetra-ortho-methoxy-substituted 2,6-diarylpyridine 7 was obtained.Deprotection of the phenol functions and bimacrocyclization with the diiodide 9 gave 4a which catalyzes the addition of alcohols to diphenylketene.