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

摘要

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 PdCl2, 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.