Catalyzed synthesis of dihydrosilaazaanthracenes-silicon- and nitrogen-containing heterocycles

3-Methyl-4-dimethylphenyl-and 3-methyl-4-diphenylsilylpyridine have been dehydrocyclized over a chromium catalyst (composition 5% chromium (III) oxide, 5% Polirite, 1% potassium oxide, and 89%γ-Al2O3) to give 10,10-diniethyl-and 10-methyl-10-phenyl-9,10-dihydro-10-sila-2-azaanthracene. © 1985 Plenum Publishing Corporation.