Intermolecular Zirconium-Catalyzed Hydrophosphination of Alkenes and Dienes with Primary Phosphines

Catalytic hydrophosphination of terminal alkenes and dienes with primary phosphines (RPH₂; R = Cy, Ph) under mild conditions has been demonstrated using a zirconium complex, [κ⁵-<i>N</i>,<i>N</i>,<i>N</i>,<i>N</i>,<i>C</i>-(Me₃SiN­CH₂CH₂)₂­NCH₂CH₂­NSiMe₂­CH]Zr (<b>1</b>). Exclusively anti-Markovnikov functionalized products were observed, and the catalysis is selective for either the secondary or tertiary phosphine (i.e., double hydrophosphination) products, depending on reaction conditions. The utility of the secondary phosphine products as substrates for further elaboration was demonstrated with a platinum-catalyzed asymmetric alkylation reaction

Visible Light Photocatalysis Using a Commercially Available Iron Compound

[CpFe­(CO)₂]₂ (<b>1</b>) (Cp = η⁵-C₅H₅) is an effective precatalyst for the hydrophosphination of alkenes with Ph₂PH under visible light irradiation, which appears to be a unique way to promote metal-catalyzed hydrophosphination. Additionally, <b>1</b> is a photocatalyst for the dehydrogenation of amine boranes and formation of siloxanes from tertiary silanes. These reactions have similar, if not improved, reactivity over the same transformations using <b>1</b> or related CpFeMe­(CO)₂ under UV irradiation, consistent with the notion that hydrophosphination with <b>1</b> proceeds via formation of CpFe­(CO)₂^•. These results demonstrate that catalyst selection can avail the use of commercially available LED bulbs as photon sources, potentially replacing mercury arc lamps or other energy intensive processes in known or new catalytic reactions