A biomass-involved strategy for the synthesis of N-arylated dibenzo[b,e][1,4]oxazepin-11(5H)-ones, acridones, 7,12-dihydrodibenzo[b,e][1,4]oxazocin-6H-ones and dibenzo[b,f]azepin-10(11H)-ones

Abstract

An efficient method for the assembly of novel and diversified benzo-fused N-heterocycles mediated by the biomass-derived N-arylated 2-aminophenol (1) has been established. Four kinds of benzo-fused N-heterocycles with six- to eight-membered ring systems, including N-arylated dibenzo[b,e][1,4]oxazepin-11(5H)-ones (4), acridones (5), 7,12-dihydrodibenzo[b,e][1,4]oxazocin-6H-ones (6) and dibenzo[b,f]azepin-10(11H)-ones (7) have been efficiently synthesized in good to excellent yields, respectively. This process is comprised of the N-arylation reaction between N-arylated 2-aminophenols (1) and 2-halogenated benzoic or phenylacetic acids to afford a series of mutli-functionalized triarylamines (3), followed by chemo- and regio-selective intramolecular lactonization or acylation under mild conditions.