Bis(diethylamino)(pentafluorophenyl)phosphane – a Push–Pull Phosphane Available for Coordination

A facile large-scale synthesis of the “push–pull”-substituted ligand bis(diethylamino)(pentafluorophenyl)phosphane is reported. A selenophosphorane as well as complexes with CuI and PdCl(2), can be formed almost quantitatively from suitable starting materials. The Pd(II) complex shows a square-planar coordination with significant distortions of the Cl–Pd–Cl moiety in the solid state. In contrast, the phosphane ligand exhibits a large flexibility in the trigonal-planar coordination of the Cu salt, as proven by X-ray crystallography. C–C cross-coupling reactions and 1,3-dipolar cycloadditions have been tested for the Pd(II) and Cu(I) complexes, respectively. Whereas the reactivity of the Pd(II) complex is good at low temperature, the Cu(I) complex reveals remarkable reaction rates at temperatures up to 130 °C. Furthermore, the Cu(I)-catalyzed azide/alkyne 1,3-dipolar cycloaddition was successfully adapted for flow conditions.