Exploration of tin-catalyzed phosphine dehydrocoupling: Catalyst effects and observation of tin-catalyzed hydrophosphination

A Study of Two Highly Active, Air‐Stable Iron(III)‐μ‐Oxo Precatalysts: Synthetic Scope of Hydrophosphination using Phenyl‐ and Diphenylphosphine

“…Extending the reaction time to 72 h increases the yield to 62%. Although a good yield, and a rare example of SHP at room temperature, the prolonged reaction time is somewhat limited: we decided to probe the potential for catalyst‐free thermal reactivity. Undertaking the hydrophosphination procedure in the absence of catalyst, under thermal conditions, gives good conversion to the SHP product (Scheme a).…”

“…4 and 5 respectively, Scheme ), depending on reagent stoichiometries, and is effective for unactivated alkenes such as 1‐hexene . Waterman and Wright also report tin‐mediated HP which operates for styrene, 2,3‐butadiene, phenylacetylene and diphenylacetylene and finally publications from Sarazin, Carpentier and Trifonov on rare earth‐catalyzed HP. These latter systems operate at 70 °C or below on styrene where a 1:1 ratio of styrene:H 2 PPh gives high levels of selectivity for the secondary phosphine product ( cf .…”

Challenges in Catalytic Hydrophosphination

“…Catalytic FLP‐mediated hydrophosphination is currently an unchartered area with much promise for development, but catalytic main‐group hydrophosphination is already gaining ground . Preliminary studies of tin‐catalyzed hydrophosphination with PhPH 2 has demonstrated modest conversion into hydrophosphination products for classic substrates such as phenylacetylene and styrene . Catalytic hydrophosphination with these species appears not to be driven by the Lewis acidity of the tin, highlighting an important distinction between those systems and stoichiometric FLP chemistry.…”

Calcium, Strontium and Barium Homogeneous Catalysts for Fine Chemicals Synthesis

“…Originally, this type of catalysis was very dependent on rhodium, palladium, and platinum. More recently, a limited variety of competent precatalysts based on copper,51 iron,50f tin,52 or more oxophilic metals, e.g., titanium/zirconium,53 alkaline earths,16 and divalent lanthanides have also been revealed 16b,16d,54. Like others, we have been interested in exploiting oxophilic Ae complexes to create CP σ‐bonds, since such compounds designed around hard elements, less prone to interacting with phosphines (i.e., to be deactivated upon excessively strong coordination of this substrate) than late‐transition complexes, could offer significant advantages over these other types of more traditional precatalysts.…”