bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; triethylamine T=20°C; Sonogashira coupling; 2 h; Inert atmosphere;

1: dimethyl (1,3-dithiol-2-yl)phosphonate With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.166667 h; 2: N-(4,5-dihexyl-1,3-dithiol-2-ylidene)piperidinium hexafluorophosphate in tetrahydrofuran; hexane T=20°C; 0.75 h; 3: With acetic acid in tetrahydrofuran; hexane 2 h;

1.1: 88 percent / acetone / 3 h / 20 °C 2.1: conc. sulfuric acid / 4 h / 20 °C 2.2: 85 percent / aq. HPF6 / 0 °C 3.1: nBuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C 3.2: tetrahydrofuran; hexane / 0.75 h / 20 °C 3.3: 2.02 g / acetic acid / tetrahydrofuran; hexane / 2 h View Scheme

1.1: conc. sulfuric acid / 4 h / 20 °C 1.2: 85 percent / aq. HPF6 / 0 °C 2.1: nBuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C 2.2: tetrahydrofuran; hexane / 0.75 h / 20 °C 2.3: 2.02 g / acetic acid / tetrahydrofuran; hexane / 2 h View Scheme

1.1: 97 percent / PPh3; CCl4 / acetonitrile / 1 h / 20 °C 2.1: 88 percent / acetone / 3 h / 20 °C 3.1: conc. sulfuric acid / 4 h / 20 °C 3.2: 85 percent / aq. HPF6 / 0 °C 4.1: nBuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C 4.2: tetrahydrofuran; hexane / 0.75 h / 20 °C 4.3: 2.02 g / acetic acid / tetrahydrofuran; hexane / 2 h View Scheme