Tris(dibenzylideneacetone)dipalladium(0)
{{chembox
|Verifiedfields = changed
|Watchedfields = changed
|verifiedrevid = 429834506
| Name=Tris(dibenzylideneacetone){{shy}}dipalladium(0)
|ImageFile1 = Pd2(dba)3.png
|ImageFile2 = Tris(dibenzylideneacetone)dipalladium(0)-3D-balls.png
| ImageFile3 = File:Tris(dibenzylideneacetone)dipalladium(0).jpg
|IUPACName = Tris(dibenzylideneacetone)dipalladium
|OtherNames = Pd2(dba)3
|Section1={{Chembox Identifiers
|CASNo_Ref = {{cascite|correct|CAS}}
|CASNo =51364-51-3
|PubChem = 9811564
}}
|Section2={{Chembox Properties
|C=51 | H=42 | O=3 | Pd=2
|MeltingPtC = 152 to 155
}}
}}
Tris(dibenzylideneacetone)dipalladium(0) or [Pd2(dba)3] is an organopalladium compound. The compound is a complex of palladium(0) with dibenzylideneacetone (dba). It is a dark-purple/brown solid, which is modestly soluble in organic solvents. Because the dba ligands are easily displaced, the complex is used as a homogeneous catalyst in organic synthesis.
Preparation and structure
First reported in 1970,{{cite journal | last1 = Takahashi | first1 = Y. | last2 = Ito | first2 = Ts. | last3 = Sakai | first3 = S. | last4 = Ishii | first4 = Y. | title = A novel palladium(0) complex; bis(dibenzylideneacetone)palladium(0) | journal = Journal of the Chemical Society D: Chemical Communications | pages = 1065 | year = 1970 | doi = 10.1039/C29700001065 | issue = 17}} it is prepared from dibenzylideneacetone and sodium tetrachloropalladate. Because it is commonly recrystallized from chloroform, the complex is often supplied as the adduct [Pd2(dba)3·CHCl3].Jiro Tsuji and Ian J. S. Fairlamb "Tris(dibenzylideneacetone)dipalladium–Chloroform" E-EROS, 2008. {{doi|10.1002/047084289X.rt400.pub2}} The purity of samples can be variable.Zalesskiy, S. S., Ananikov, V. P., "Pd2(dba)3 as a Precursor of Soluble Metal Complexes and Nanoparticles: Determination of Palladium Active Species for Catalysis and Synthesis", Organometallics 2012, 31, 2302. {{doi|10.1021/om201217r}}
In [Pd2(dba)3], the pair of Pd atoms are separated by 320 pm but are tied together by dba units.{{cite journal | last1 = Pierpont | first1 = Cortlandt G. | last2 = Mazza | first2 = Margaret C. | title = Crystal and molecular structure of tris(dibenzylideneacetone)dipalladium(0) | journal = Inorg. Chem. | volume = 13 | pages = 1891 | year = 1974 | doi = 10.1021/ic50138a020 | issue = 8}} The Pd(0) centres are bound to the alkene parts of the dba ligands.
Applications
[Pd2(dba)3] is used as a source of soluble Pd(0), in particular as a catalyst for various coupling reactions. Examples of reactions using this reagent are the Negishi coupling, Suzuki coupling, Carroll rearrangement, and Trost asymmetric allylic alkylation, as well as Buchwald–Hartwig amination.{{cite book | last = Hartwig | first = J. F. | title = Organotransition Metal Chemistry, from Bonding to Catalysis | publisher = University Science Books | place = New York | year = 2010 | isbn = 978-1-891389-53-5}}
Related Pd(0) complexes are [Pd(dba)2]John R. Stille, F. Christopher Pigge, Christopher S. Regens, Ke Chen, Adrian Ortiz and Martin D. Eastgate "Bis(dibenzylideneacetone)palladium(0)"
E-eros. 2013. {{doi|10.1002/047084289X.rb138.pub3}} and tetrakis(triphenylphosphine)palladium(0).