Recent advances in carbazole syntheses

The tricyclic carbazole heterocycle is an essential component of many biologically active natural products, drug-like compounds, and valuable pi-extended building blocks for advanced materials that exhibit potential for use in opto- and thermoelectronic applications. The synthesis of carbazoles has been an active area of research in Organic Synthesis for decades. This chapter reviews newly emerging methodology reported for carbazole synthesis in the years 2008-2017. The synthetic methods are organized following a mechanistic classification, according to the strategy and catalytic system used for the key cyclization step in each synthesis.