Recent Advances in Synthesis of Pyrrolo[3,2‐b]indole and Indolo[3,2‐b]indole Derivatives

Abstract

During the last 15 years, many teams have developed new accesses to pyrrolo[3,2‐b]indoles, indolo[3,2‐b]indoles, and polycyclic counterparts for finding either new synthetic pathways or their electronic and photochromic properties. In this review, we have listed the new methodologies accessing this type of nuclei published between 2007 and the end of 2021 through novel strategies using metal or non‐metal salts. Significant examples of functionalized compounds illustrate the syntheses. We also present the properties of a selection of these heterocycles and evoke some reaction mechanisms.

Mo-catalyzed cyclization of N-vinylindoles and skatoles: synthesis of dihydroindolo[1,2-c]-quinazolines and dihydroindolo[3,2-b]-indoles, and evaluation of their anticancer activities

“…The absence of the methyl group on the skatole allows C–H insertion on the carbon of the C3 position of the indole, preferentially over the enamine terminal carbon (see infra for the mechanism). Owing to the electron-rich and ease of oxidation of the DINI scaffold, materials incorporating DINI structures 28 have found extensive applications in organic electronics, including organic photovoltaics 29 and organic light-emitting diodes (LEDs). 30 Also, compounds 6a–g were successfully synthesized using our standard conditions in good yields.…”