1.1: acetonitrile / Inert atmosphere 2.1: manganese(IV) oxide / dichloromethane / Inert atmosphere 3.1: caesium carbonate / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 3.2: Inert atmosphere 4.1: trifluoroacetic acid / acetonitrile / 80 °C 5.1: trichloromonobromomethane; trifluoroacetic acid / acetonitrile / 80 °C View Scheme

1.1: acetonitrile / Inert atmosphere 2.1: manganese(IV) oxide / dichloromethane / Inert atmosphere 3.1: caesium carbonate / N,N-dimethyl-formamide / 1 h / 20 °C / Inert atmosphere 3.2: Inert atmosphere 4.1: iodine; trifluoroacetic acid / acetonitrile / 80 °C View Scheme

manganese(IV) oxide; acetic acid in acetonitrile T=23°C; 1 h;