Reactivity Of Cyrhetrenylphosphines: Synthesis And Characterization Of Oxides, Boranes And Selenides

Reaction of cyrhetrenylphosphines, of general formula (η5-C5H4PR2)Re(CO)2L (R = Ph, L = CO (1); R = Cy; L = CO (2); R = Ph, L = PMe3 (3) and R = Ph, L = P(OMe)3 (4)), with H2O2, BH3·THF or selenium gives the respective cyrhetrenylphosphine oxides, boranes and selenides. These species were characterized by standard spectroscopic techniques (FT-IR, 1H and 31PNMR). Based on the 31P[sbnd]77Se coupling constant (1JP-Se) of the phosphine-selenides, we established the following order of basicity of the parent cyrhetrenylphosphine 2 > 3 > 4 > 1. We also confirmed the opposite electronic effects of the cyrhetrenyl and ferrocenyl groups attached to a –PR2 unit. Finally, phosphine selenides 2c and 4c were structurally characterized by X-ray diffraction.