190141-88-9

Upstream product

• 13146-23-1 copper(I) phenylacetylide 
• 926906-35-6 trans-Pd(I)(C₆H₄OMe-p)(PMe₃)2 
• 190141-83-4 trans-Pd(C*CPh)(C₆H₄Me-p)(PEt₃)2 

Relevant academic research and scientific papers

Intermolecular alkynyl-ligand migration from aryl-palladium(II) to -platinum(II) complexes with and without a CuI catalyst. Reversible transfer of the alkynyl group between copper(I) and palladium(II) complexes

Alkynyl-ligand transfer from [PdR(OCPh)L2] (R = C6H4Me-p, L = PEt3) to [PtR′(I)L2] (R′ = C6H4OMe-p), to give [PdR(I)L2] and [PtR′(GCPh)L2], has been enhanced to a large extent by addition of CuI, indicating reversible ligand transfer between PdII and CuI complexes.

Preparation and properties of trans-Pd(Ar) (C≡CPh) (PEt3)2. Intermolecular alkynyl ligand transfer between copper(I) and palladium(II) complexes relevant to palladium complex catalyzed cross-coupling of terminal alkyne with haloarene in the presence of CuI cocatalyst

trans-Pd(C6H4Me-p)(I)(PEt3)2 (2a) reacts with [Cu(C≡CPh)(PPh3)]4 (Pd:Cu = 1:1) at room temperature to give the cross-coupling product PhC≡CC6H4Me-P (3a) in 74% yield. Reactions of 2a with [Cu(C≡CPh)(PPh3)I4 at -30 °C as well as of trans-Pd(C6H4X-P)(I)(PEt3)2 (2a, X = Me; 2b, X = OMe; 2c, X = F) with the alkynylcopper complex and additional PPh3 (2 mol/ mol of Cu) at room temperature give mixtures of PhC≡CC6H4X-P (3a, X = Me; 3b, X = OMe; 3c, X = F) and trans-Pd(C6H4X-P)(C≡CPh)(PEt3) 2 (4a, X = Me; 4b, X = OMe; 4c, X = F). Complexes 4a,b have been isolated from the latter reaction mixtures and fully characterized. Pd-C(alkynyl) and Pd-C(aryl) bond distances in 4a are 2.016(8) and 2.062(7) A, respectively. Addition of Cul to a solution of 4a at room temperature causes complete conversion of 4a into 2a and 3a in 1 h. The relative molar ratio between 2a and 4a after reaction for 2 h varies, depending on the amount of added PPh3. Reactions of trans-Pt(C6H4X-p)(I)(PEt3)2 (5b, X = OMe; 5c, X = F) with [Cu(C≡CPh)(PPh3)]4 at room temperature afford trans-Pt(C6H4X-p)(C≡CPh)(PEt3) 2 (6b, X = OMe; 6c, X = F), respectively. Heating an equimolar mixture of 4a and 5b at 35-50 °C leads to inter-metal exchange of the alkynyl and iodo ligands, giving 2a and 6b quantitatively. The reaction follows the kinetics that is first order in concentration of 4a and in that of 5b. The kinetic parameters are obtained as ΔH? = 110 kJ mol-1, ΔS? = -58 J mol-1 deg-1, and ΔG? = 127 kJ mol-1 at 298 K. The alkynyl ligand migration from Pd(II) to Pt(II) is enhanced by addition of a catalytic amount of CuI.