Iodide-Dependent Selective Dehydroaromatization Affording Maleimide-Fused 9,10-Phenanthrenes and Their Analogues

Abstract

A novel and selective synthesis of polycyclic fused maleimides from easily available raw materials under metal-free conditions is presented. This cascade protocol involves selfcondensation of cyclohexanones, followed by Diels−Alder reaction with maleimides, intramolecular dehydration, and selective dehydroaromatization in a one-pot fashion, affording maleimidefused 9,10-phenanthrenes and their analogues in satisfactory yields. Notably, iodide reagents play a critical role in switching the selectivity toward full or partial dehydrogenation compounds.

Functionalized Phenanthrene Imide‐Based Polymers for n‐Type Organic Thin‐Film Transistors

“…However, imide functionalized PhAs are seldom developed, mainly attributed to the challenge to selectively introduce imide onto PhA to realize the strong electronpulling capability. [17] Several works reported the synthesis of PhA-based monoimides by introducing imide group on 9 and 10 positions of PhA, recently. [17] On the other side, multiple reactive sites on phenanthrene also provide the possibilities for further structural functionalization by introducing a second EWG to attain higher electron-deficiency.…”

“…[17] Several works reported the synthesis of PhA-based monoimides by introducing imide group on 9 and 10 positions of PhA, recently. [17] On the other side, multiple reactive sites on phenanthrene also provide the possibilities for further structural functionalization by introducing a second EWG to attain higher electron-deficiency.…”

Synthesis of Phenanthrenes and 1-Hydroxyphenanthrenes via Aromatization-Assisted Ring-Closing Metathesis: toward Polynuclear Aromatic Hydrocarbons

“…In addition to the conventional method of synthesizing phenanthrenes via intramolecular C–C bond formation using McMurry coupling reactions and cross-coupling reactions, several alternative approaches have been developed to address the challenges such as restricted compatibility with functional groups and the need for stoichiometric amounts of transition metal reagents. − These methods include cycloisomerization, C–H annulation, photoirradiation, and intramolecular alkyne–carbonyl metathesis. , …”