Hydrophosphinations ruthenium

Metal complex chemistry, homogeneous catalysis and phosphane chemistry have always been strongly connected, since phosphanes constitute one of the most important families of ligands. The catalytic addition of P(III)-H or P(IV)-H to unsaturated compounds (alkene, alkyne) offers an access to new phosphines with a good control of the regio- and stereoselectivity [98]. Hydrophosphination of terminal nonfunctional alkynes has already been reported with lanthanides [99, 100], or palladium and nickel catalysts [101]. Ruthenium catalysts have made possible the hydrophosphination of functional alkynes, thereby opening the way to the direct synthesis of bidentate ligands (Scheme 8.35) [102]. 

Scheme 35 Proposed mechanism for ruthenium-catalyzed hydrophosphination of a nj-alcohol via nucleophilic attack on a vinylidene complex Pargyl...

Phosphorus nucleophiles can also be added to Ca of ruthenium vinylidenes. Dixneuf and coworkers reported the efficient Ru-catalyzed anti-Markovnikov cis hydrophosphination of propargyl alcohols to vinyl phosphines (Scheme 24) [123]. 

The ruthenium-catalyzed hydrophosphination of propargyl alcohols has been reported (Scheme 4.308) [473]. Similar to the rhodium-catalyzed reaction described previously, this reaction was attractive as it facilitated the construction of these valuable fragments without protection/deprotection of the alcohol. During their initial studies, the authors discovered that the composition of the ruthenium catalyst was critical to the selectivity of the addition reaction. While many common ruthenium compounds promoted the reaction, most of them exhibited poor selectivity. The ruthenium compound that displayed the best combination of activity and selectivity was RuCl(cod)(C5Me5). Using this catalyst, the addition reaction strongly favored the Z-isomers, and E/Z ratios were reported to... 

Hydrophosphination of propargylic alcohols with ruthenium catalysts RuCl (PPh3)2Cp and RuCl(cod)Cp resulted in the product formation with the phosphorus atom attached to terminal position (Scheme 8.59) [143]. The reaction mechanism was proposed to involve intermediate ruthenium vinylidene species. 

J6r6me F, Monnier F, Lawicka H, Derien S, Dixneuf PH (2003) Ruthenium catalyzed regioselective hydrophosphination of propargyl alcohols. Chem Commun 696-697... 

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