Tris dibenzylideneacetone dipalladium-Chloroform

Form Supplied in deep purple needle-like crystals commercially available. 

Preparative Methods the reaction of Na2[Pd2Cl6] (from palla-dium(ll) chloride and NaCl) and dibenzylideneacetone (dba) gives bis(dibenzylideneacetone)palladium(0), [Pd(dba)2], which is formulated more correctly as [Pd2(dba)3]dba. Recrystallization from chloroform displaces the uncoordinating dba with chloroform to give the title reagent as deep purple needles.  

Sources of Palladium(O). Many reactions are catalyzed by Pd catalysts. The Pd catalysts are prepared in two ways. One common method for generation of Pd species involves in situ reduction of Pd salts, most conveniently palladium(II) acetate. An alternative involves the use of air-stable, commercially available Pd2(dba)3 as a Pd catalyst with or without added phosphine. The dba ligand is displaced by the addition of phosphine ligands (eq 1). Some reactions catalyzed with and without added phosphine ligands are described below. 

Coupling of Enol Triflates with Organotin Reagents. Coupling of an enol triflate with (Z)-1 -propenyltri-n-butyltin proceeds smoothly using Pd2(dba 3 as a catalyst in the absence of a phosphine ligand (eq 5).  

Ene Reactions. An intramolecular palladium-ene reaction that proceeds smoothly using Pd2(dba)3 in the presence of triph-enylphosphine is shown in eq 2.  

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Pd2(dba)3 CHCI3, [tris(dibenzylideneacetone)dipalladium-(chloroform)], HCO2H, 74-100% yield. "... 

For additional discussion about palladium-catalyzed coupling reactions, see also those entries dealing with organopalladium catalysis (e.g. tetrakis(triphenylphosphine)palladium(0), tris-(dibenzylideneacetone)dipalladium-chloroform, and ( )-l-tri-methylsilyl-2-trimethylstannylethylene. 

Related Reagents. Palladium(II) Acetate palladium(II) Chloride l,P-Bis(diphenylphosphino)ferrocene Triphenylphosphine Tris(dibenzylideneacetone)dipalladium-Chloroform. 

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