A Facile Route to Benzoannelated Centrotriquinanes

In contrast, NSF, reacts with HF/AsF, to afford the stable and isolable pentafluorosulfanylammonium salt 6['2,'41. The dimethylamino group in 5 reduces the electrophilicity of the central sulfur atom to such an extent that F" can no longer add to increase the coordination number; in this way, all subsequent steps to a product analogous to 6 are blocked. The salts 3 are stable, colorless solids (m.p.=lOl"C (3a), 103°C (3b)) that are readily attacked by nucleophiles, e.g. H,O or X" of NaCIand KBr-IR plates. They were characterized by elemental analysis and by IR and NMR spectroscopy (Table 1). Bands at 945 and 910 cm-' in the IR spectrum are assigned to the v,,(SF) and vsym(SF) vibrations.