Scheme 3. Synthesis of medicinally important quinolines using metal-free halogenation. Reagents and conditions: (a) (i) 1am, NIS, CHCl₃, 40 °C, 24 h. (ii) 7-Iodoquinolin-8-ol (14), TCCA (1.05 equiv.), CH₃CN, rt, 2 h. (b) 1ai TBCA (1.05 equiv.), CH₃CN, rt, 30 min. (c) 12, TCCA (2.2 equiv.), CH₃CN, rt, 6 h. (d) SeO₂, toluene, reflux, 4 h. (e) 13, TBCA (1.05 equiv.), CH₃CN, rt, 20 min. (f) Pyridin-3-ylboronic acid (17), Na₂CO₃, PdCl₂(PPh₃)₂, 1,4-dioxane : water (3 : 1), MW, 100 °C, 20 min.