Progresses in Synthetic Methods of Carbazole and Its Derivatives

Carbazole and its derivatives are a class of important nitrogen-containing heterocyclic compounds possessing various unique properties and biological activity.Herein the current progress of their synthetic strategies reported in the past 5 years is reviewed.The representative examples, which have been divided into four categories according to the usage of different key intermediates, are selected and discussed in detail.Special emphasis is put on the newly developed cyclization reactions which may be useful for the construction of the tricyclic backbone of carbazoles.