We describe the synthesis of 1,1'- and 2,2'-bicarbazoles by oxidative homocoupling of 2- and 1-hydroxycarbazoles. The oxidative coupling using catalytic amounts of F PcFe can be applied to both groups of substrates. Although F PcFe generally provides the best yields for the synthesis of 1,1'-bicarbazoles, di-tert-butyl peroxide affords better results for the 2,2'-bicarbazoles. In our study, we have achieved the first syntheses of the biscarbalexines A-C, bisglybomine B, 2,2'-dihydroxy-7,7'-dimethoxy-3,3'-dimethyl-1,1'-bicarbazole, bispyrayafoline C, and bisisomahanine. The iron-catalyzed coupling of koenigine led to an improved synthesis of 8,8''-biskoenigine and afforded an unprecedented decacylic product. Oxidative coupling of 1-hydroxycarbazoles led to bisclausenol, and to the first total syntheses of bismurrayafoline B and D.

We describe a regioselective synthesis of 4- or 5-substituted carbazoles by oxidative cyclisation of meta-oxygen-substituted N-phenylanilines. Using the regiodirecting effect of a pivaloyloxy group, we prepared 4-hydroxycarbazole, a precursor for the enantiospecific synthesis of the β-adrenoreceptor antagonists (-)-(S)-carazolol (5) and (-)-(S)-carvedilol (6). Regioselective palladium(II)-catalysed cyclisation of different diarylamines led to total synthesis of glycoborine (7) and the first total syntheses of the phytoalexin carbalexin A (8), glybomine A (9) and glybomine B (10). For glybomine B (10), a 5-hydroxycarbazole was converted into the corresponding triflate and utilized for introduction of a prenyl substituent.

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We describe the first total synthesis of the cytotoxic carbazole alkaloid excavatine‐A. The carbazole framework was constructed through double C–H bond activation of a diarylamine by using our palladium(II)‐catalyzed oxidative cyclization. Treatment of the intermediate 8‐hydroxycarbazoles with prenal and different additives led either to pyrano[2,3‐a]carbazoles or to [1,4]oxazepino[2,3,4‐jk]carbazoles. The pyran annulation was investigated to determine the influence of substitution pattern, additives, and reaction time on the selectivity.

We describe the first total synthesis of the pyrano[3,2-a]carbazole alkaloid 7-isovaleryloxy-8-methoxygirinimbine, using a palladium(II)-catalyzed double C–H-bond activation for construction of the carbazole framework and a phenylboronic acid catalyzed annulation of the pyran ring as key steps.