1: 9-methyl carbazole With boron trichloride; 4-(N,N-diethylamino)-toluene in dichloromethane T=20°C; 16 h; Inert atmosphere; 2: 2,3-dimethylbutane-2,3-diol With triethylamine in dichloromethane T=20°C; 0.5 h; Inert atmosphere;

AlCl3; 2,6-lutidine in dichloromethane 1:1 mixt. of BCl3 and AlCl, pinacol (2.3-3.0 equiv.) and lutidine (15 equiv.) for 14 h;

Et3N in dichloromethane byproducts: Et3NH-AlCl4; to borenium cation made in situ (in Schlenk, to soln. Et2N (CH2Cl2) added Cl4CatBCl, AlCl3; stirred) at 20°C arene added (CH2Cl2); excessEt3N added; pinacol added; stirred for 24 h;; (11)B (1H) NMR; volatiless remowed under vac; extracted (hexane); filtered through silica; removal of solvent;;

triethylamine in dichloromethane T=20°C; 1.25 h; Inert atmosphere;

1: AlCl3, aluminium chloride; boron trichloride; 4-(N,N-diethylamino)-toluene / dichloromethane / 16 h / 20 °C / Inert atmosphere 2: triethylamine / dichloromethane / 1.25 h / 20 °C / Inert atmosphere View Scheme

AlCl3, aluminium chloride; boron trichloride; 4-(N,N-diethylamino)-toluene 1 h;