Controlling Secondary Alkyl Radicals: Ligand Effects in Chromium-Catalyzed C–P Bond Formation

Chromium cyclopentadienyl β-diketiminate catalysts have been used to form Ph2PCy from Ph2PY (Y = Cl, PPh2, H) and CyX (X = Br, Cl) substrates. Manganese powder activated by PbX2 or Me3SiCl was used as the stoichiometric reductant. The Cr­(III) cyclohexyl intermediate has been synthesized and structurally characterized. The observed variations in catalytic activity have been correlated with the previously observed reactivity differences imparted by modifying the N-aryl substituents on the β-diketiminate ancillary ligand.