Synthesis of Heterocycles through Nitrenes

Abstract

The reaction of triethyl phosphite with aromatic nitro compounds in which a nitrene intermediate was expected to intervene was investigated.Syntheses of certain indole d e r i v a t i v e s , such as harman, pseudorutaecarpine , benz[a]carbaaole and p-carboline; and quinoline derivatives that a r e related to natural products a r e d e s c r i b e d in t h i s review.It i s known that trivalent organophosphorous compounds, such as trialkyl phosphites and phosphines ( x ~P ) r e a c t with many oxygen containing compounds 1 t o give pentavalent phosphates.In 1962, Cadogan and co-workers applied this reaction to nitro and nitroso compounds.They found that c a r b a ~o l e derivatives ( 2 ) were obtained from 2nitroso-and 2-nitrobiphenyls (1) by refluxing with triethyl phosphite.2,3,4 HETEROCYCLES, Val. 2, No. 2, 1974