Polyalkynylated naphthalenes were obtained from easily available 2,3‐dibromobenzoquinone. The developed methodology consists of a substitution of both carbonyl groups of the quinone moiety by lithium acetylide followed by a Pd‐catalyzed cross‐coupling reaction. Optical properties of selected compounds were studied.

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dibromo-1,4-naphthoquinone 1 (0.3 mmol), the appropriate amine (0.3 mmol) and H 2 O (1 mL) were poured into a pressure tube. The reaction was set up at 60 C for 6 h, then, 2-bromophenylboronic acid (0.3 mmol), Pd (PPh 3) 4 (5 mol%), Pd 2 dba 3 (5 mol%), RuPhos (10 mol%), K 3 PO 4 (0.9 mmol) and 1,4dioxane (10 mL) were added under argon. The tube was sealed with a Teflon valve and stirred at 90 C. After 24 h, the mixture was allowed to reach room temperature, diluted with water and extracted with dichloromethane. The combined organic layers were dried over sodium sulfate and concentrated under vacuum. The crude material was purified by flash column chromatography on silica gel. Procedure B: An argon purged pressure tube was charged with 2,3-dibromo-1,4-naphthoquinone 1 (0.3 mmol) and the secondary amine (0.3 mmol), Pd (OAc) 2 (5 mol%), PPh 3 (10 mol%), tBuONa (0.9 mmol) and toluene (10 mL). The reaction was set up at 90 C for 24 h. Afterwards the mixture was allowed to reach room temperature, was diluted with water and extracted with ethyl acetate. The combined organic layers were dried over sodium sulfate and concentrated under vacuum. The crude material was purified by flash column chromatography on silica gel. 5 Analytical data 2-Bromo-3-(p-tolylamino)naphthalene-1,4-dione (2b) Starting from p-toluidine with 2,3-dibromonaphthalene-1,4-dione in water at 60 C for 6 h, 2b was obtained as a dark red solid, mp = 157-158 C. 1 H NMR (300 MHz,

A two-step palladium-catalyzed procedure based on Suzuki–Miyaura cross coupling, followed by a double Buchwald–Hartwig reaction, allows for the synthesis of pharmaceutically relevant benzo[4,5]furo[3,2-b]indoles in moderate to very good yield. The synthesized compounds have been analyzed with regard to their inhibitory activity (IC50) of nucleotide pyrophosphatases h-NPP1 and h-NPP3. The activity lies in the nanomolar range. The results were rationalized based on docking studies.

Two new and efficient methods for the synthesis of benzo[b]carbazolediones have been developed. Various derivatives were synthesized by either a three‐component one‐pot reaction or a two‐component domino reaction in moderate to good yield. Moreover, inhibition studies of these compounds against nucleotide pyrophosphatases (NPPs) have been carried out. An interesting and promising inhibitory effect was observed by the influence of different substituents. Substitution with a methyl group located at the indole moiety was found sensitive towards h‐NPP1 (4b; IC50 ±SEM = 0.57 ± 0.05 μM), while the unsubstituted derivative exhibited a higher sensitivity towards h‐NPP3 (4a; IC50 ± SEM = 0.16 ± 0.06 μM). Both derivatives presented non‐selective inhibition of both isozymes. Among all the derivatives, two derivatives with anisyl groups showed the highest selectivity towards h‐NPP3 and no interaction with h‐NPP1. Finally, the free binding energies were calculated and molecular docking studies were performed in order to provide an insight into putative binding modes of these inhibitors.