ZnCl<sub>2</sub>-Promoted Intramolecular Hetero-Diels–Alder Reaction of <i>o</i>-Alkynylphenylcarbodiimides for Synthesis of Dihydrodibenzo[<i>b</i>,<i>g</i>][1,8]naphthyridines
The ZnCl2-promoted intramolecular heteroDiels-Alderreaction of N-(ortho-propargylphenyl)-N'-arylcarbodiimides, in which the aryl-N=C moiety functioned as a 2-azabuta-1,3-diene, 4pi component, has been achieved. By this method, very rare 5,12-dihydrodibenzo[b,g][1,8]naphthyridines and fully aromatized dibenzo[b,g][1,8]naphthyridines were successfully synthesized.
Thermal Cyclization of Nonconjugated Aryl-Yne-Carbodiimide Furnishing a Dibenzonaphthyridine Derivative
作者:Hidenori Kimura、Kohei Torikai、Ikuo Ueda
DOI:10.1248/cpb.57.393
日期:——
The reagent-free C2–C7 thermal cyclization of a nonconjugated aryl–yne–carbodiimide yielded a dibenzo[b,g][1,8]naphthyridine derivative, whose congeners are known to possess fascinating pharmacological properties. This is the first heteroaromatic compound prepared by the thermal cycloaromatization of “nonconjugated” aryl–ynes.