Synthesis of N‐Fused Indolines via Copper (II)‐Catalyzed Dearomatizing Cyclization of Indoles

Abstract

Herein, a copper(II)-catalyzed dearomative cyclization amination of N-(2-aminobenzoyl) indoles is presented. Under mild reaction conditions, the cyclization proceeds to afford tetracyclic indolines by forming a new C−N bond in good yields. The tetracyclic 5a,6-dihydroindolo[2,1-b]quinazolin-12(5H)-ones are obtained in good to excellent yields (up to 99% yield) by using trifluoromethanesulfonic acid (TfOH) mediated N−Ts bond cleavage. The obtained compounds could be easily functionalized by simple synthetic methods.