185812-86-6Relevant articles and documents
Synthesis and Structural Characterisation of : A Tetrahedral Palladium Cluster with a μ3-Methylidyne Ligand
Burrows, Andrew D.,Mingos, D. Michael P.,Menzer, Stephan,Vilar, Ramon,Williams, David J.
, p. 2107 - 2108 (1995)
The compound has been synthesised from (dba = dibenzylideneacetone), P(t-Bu)3 and CHCl3 and characterised spectroscopically and by single-crystal X-ray analysis; it undergoes substitution reactions with Br(1-) and tertiary phosphines and is a catalyst for the polymerisation of ethyne.
Synthesis and structural characterisation of [Pd2(μ-Br)2(PBut3)2], an example of a palladium(I)-palladium(I) dimer
Vilar, Ramon,Mingos, D. Michael P.,Cardin, Christine J.
, p. 4313 - 4314 (1996)
The syntheses, spectroscopic characterisation and in one case (X = Br) the single-crystal structure of the novel PdI-PdI dimers [Pd2(μ-X)2(PBut3)2] (X = Br or I) have been determined; preliminary results on their reactions with CO, H2, CNC6H3Me2 and C2H2 have also been obtained.
PROCESS
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, (2018/05/16)
The present invention provides a process for the preparation of a complex of formula (I): comprising the step of reacting Pd(diolefin)X2 or PdX2 and PR1 R2R3 in a solvent to form the complex of formula (I), wherein the process is carried out in the absence of a base, the molar ratio of Pd(diolefin)X2 : PR1 R2R3 or PdX2 : PR1 R2R3 is greater than 1 : 1.1, up to about 1 :2.5; each X is independently a halide; and R1, R2 and R3 are independently selected from the group consisting of tert-butyl and isopropyl.
Ex situ generation of stoichiometric HCN and its application in the Pd-catalysed cyanation of aryl bromides: Evidence for a transmetallation step between two oxidative addition Pd-complexes
Kristensen, Steffan K.,Eikeland, Espen Z.,Taarning, Esben,Lindhardt, Anders T.,Skrydstrup, Troels
, p. 8094 - 8105 (2017/11/27)
A protocol for the Pd-catalysed cyanation of aryl bromides using near stoichiometric and gaseous hydrogen cyanide is reported for the first time. A two-chamber reactor was adopted for the safe liberation of ex situ generated HCN in a closed environment, which proved highly efficient in the Ni-catalysed hydrocyanation as the test reaction. Subsequently, this setup was exploited for converting a range of aryl and heteroaryl bromides (28 examples) directly into the corresponding benzonitriles in high yields, without the need for cyanide salts. Cyanation was achieved employing the Pd(0) precatalyst, P(tBu)3-Pd-G3 and a weak base, potassium acetate, in a dioxane-water solvent mixture. The methodology was also suitable for the synthesis of 13C-labelled benzonitriles with ex situ generated 13C-hydrogen cyanide. Stoichiometric studies with the metal complexes were undertaken to delineate the mechanism for this catalytic transformation. Treatment of Pd(P(tBu)3)2 with H13CN in THF provided two Pd-hydride complexes, (P(tBu)3)2Pd(H)(13CN), and [(P(tBu)3)Pd(H)]2Pd(13CN)4, both of which were isolated and characterised by NMR spectroscopy and X-ray crystal structure analysis. When the same reaction was performed in a THF : water mixture in the presence of KOAc, only (P(tBu)3)2Pd(H)(13CN) was formed. Subjection of this cyano hydride metal complex with the oxidative addition complex (P(tBu)3)Pd(Ph)(Br) in a 1 : 1 ratio in THF led to a transmetallation step with the formation of (P(tBu)3)2Pd(H)(Br) and 13C-benzonitrile from a reductive elimination step. These experiments suggest the possibility of a catalytic cycle involving initially the formation of two Pd(ii)-species from the oxidative addition of LnPd(0) into HCN and an aryl bromide followed by a transmetallation step to LnPd(Ar)(CN) and LnPd(H)(Br), which both reductively eliminate, the latter in the presence of KOAc, to generate the benzonitrile and LnPd(0).
