Synthesis of benzo-fused heterocycles by intramolecular α-arylation of ketone enolate anions

摘要

A two-step synthesis of six-, seven-, eight-, and nine-member benzo-fused heterocycles in good to excellent yields is reported. The synthetic strategy involves the generation of a new intramolecular α-aryl ketone bond by the photostimulated S _(RN)1 reaction of ketone enolate anions linked to a pendant haloarene as the key step. On the other hand, an intramolecular C _(Ar)-C _(Ar) coupling led to the formation of five- and six-member benzo-fused heterocycles (9H-carbazole and phenanthridine) when an aromatic amide anion is competitively formed.