73664-46-7Relevant academic research and scientific papers
N-Acetyl-N,N-dipyrid-2-yl (cyclooctadiene) rhodium (I) and iridium (I) complexes: Synthesis, X-ray structures, their use in hydroformylation and carbonyl hydrosilylation reactions and in the polymerization of diazocompounds
Bantu, Bhasker,Wurst, Klaus,Buchmeiser, Michael R.
, p. 5272 - 5278 (2008/02/13)
The synthesis of novel N-acetyl-N,N-dipyrid-2-yl complexes of RhI and IrI, i.e. [RhCl(CH3CONPy2)(COD)] (1) and [IrCl(CH3CONPy2)(COD)] (2), respectively, is described. Upon prolonged treatment in CH2Cl2 at room temperature, complex 1 is transformed into a cationic Rh-complex, i.e. [Rh(CH3CONPy2)(COD)+RhCl2(COD)-] (1a). Compound 1a crystallizes in the monoclinic space group P21/c, complex 2 crystallizes in the triclinic space group P over(1, ?). Compound 1 was investigated for its catalytic activity in the hydroformylation of cyclooctene as well as of 1-octene. In addition, 1 was used in various carbonyl hydrosilylation reactions of both aldehydes and ketones. There, turn-over numbers up to 50 000 and yields in the range of 85-100% were observed. Finally, compound 1 was successfully used for the polymerization of N2CHCOOEt yielding highly stereoregular poly(ethoxycarbonylcarbene) with Mw = 67 000 g/mol and a polydispersity index (PDI) of 2.59.
Access to well-defined heterogeneous catalytic systems via ring-opening metathesis polymerization (ROMP): Applications in palladium(II)-mediated coupling reactions
Buchmeiser, Michael R.,Wurst
, p. 11101 - 11107 (2007/10/03)
The preparation of a new heterogeneous palladium(II)-based catalyst and its homogeneous analogue and their use for Heck-type, alkyne and amine couplings are described. The heterogeneous catalytic system is based on a polymer-bound dichloropalladium di(pyrid-2-yl)amide and was prepared via ring-opening metathesis copolymerization of norborn-2-ene-5-(N,N-di(pyrid-2-yl))carbamide with 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exoendo-dimethanonaphthalene and subsequent loading of the resulting resin with palladium(II) chloride. The heterogeneous catalyst is air, moisture, and temperature stable up to 150 °C and highly active (94-99% yields) in the vinylation of aryl iodides and aryl bromides (Heck-type couplings) with turn-over numbers (TONs) of up to 210000. Even higher TON's (up to 350000) may be achieved in the arylation of alkynes. High yields (≤95%) and TONs (≤24000) may additionally be achieved in the tetrabutylammonium bromide (TBAB) assisted vinylation of aryl chlorides. Moderate yields (1/n, a = 835.0(1) pm, b = 1494.3(4) pm, c = 1199.3(2) pm, α = 90°, β = 109.05(2)°, γ = 90°, Z = 4. It served as a model compound for the elucidation of the actual geometry of the catalytic species. The unstrained geometry of 2 with almost ideal angles and bond lengths explaines the high stability of the catalytic center. The significantly higher catalytic activity of the heterogeneous system compared to the homogeneous one suggests well-defined ligand-bound catalytic sites rather than polymer-supported palladium colloids.
