Synthesis of Spiro Polycyclic N-Heterocycles and Indolecarbazoles via Merging Oxidative Coupling and Cascade
Yu Dong1, Mei-Feng Lan1, Yue-Qin Lin1
1College of Chemistry and Life Science, Sichuan Provincial Key Laboratory for Structural Optimization and Application of Functional Molecules, Chengdu Normal University, Chengdu 611130, P. R. China.
Abstract:
We report a step-economic strategy for the direct synthesis of spiro polycyclic N-heterocycles and indolecarbazole-fused naphthoquinones by merging oxidative coupling and cascade palladium-catalyzed intramolecular oxidative cyclization. In the protocol, bi-indolylnaphthoquinones were first synthesized by oxidative coupling of indoles and naphthoquinones. Subsequent cascade palladium-catalyzed intramolecular oxidative cyclization of bi-indolylnaphthoquinones gave spiro polycyclic N-heterocycles and indolecarbazoles. The intramolecular oxidative cyclization approach could also be realized by the presence or absence of iron catalysts under standard conditions. This protocol is featured with moderate to excellent yields, a wide substrate scope, and divergent structures of products.
Related Concept Videos
Cycloaddition Reactions: Overview
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Cycloaddition Reactions: MO Requirements for Photochemical Activation

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
