The synthesis of biologically active indolocarbazole natural products

Covering: up to 2020 The indolocarbazoles, in particular indolo[2,3- a ]pyrrolo[3,4- c ]carbazole derivatives, are an important class of natural products that exhibit a wide range of biological activities. There has been a plethora of synthetic approaches to this family of natural products, leading to advances in chemical methodology, as well as affording access to molecular scaffolds central to protein kinase drug discovery programmes. In this review, we compile and summarise the synthetic approaches to the indolo[2,3- a ]pyrrolo[3,4- c ]carbazole derivatives, spanning the period from their isolation in 1980 up to 2020. The selected natural products include indolocarbazoles not functionalised at indolic nitrogen, pyranosylated indolocarbazoles, furanosylated indolocarbazoles and disaccharideindolocarbazoles. Syntheses of indolo[2,3- a ]pyrrolo[3,4- c ]carbazole natural products are discussed, including staurosporine aglycone, arcyriaflavins, and glycosylated derivatives including staurosporine, rebeccamycin and K252A.