728-86-9Relevant articles and documents
Synthesis, coordination and catalytic use of phosphinoferrocene ligands bearing 6-phospha-2,4,6-trioxaadamantane P-donor moieties
?těpni?ka, Petr,Císa?ová, Ivana,Horky, Filip
, (2021/11/11)
1,1’-Bis(diphenylphosphino)ferrocene (dppf) and structurally related ferrocene bis-phosphines are indispensable ligands for coordination chemistry and catalysis. This contribution focuses on the coordination behaviour and catalytic properties of two dppf congeners bearing 1,3,5,7-tetramethyl-2,4,6-trioxa-8-phosphatricyclo[3.3.1.13,7]decane-8-yl groups (CgP) as the P-donor moieties, viz. Ph2PfcCgP (1) and its semi-homologous counterpart Ph2PfcCH2CgP (2; fc = ferrocene-1,1’-diyl). In reactions with a PdCl2 source, compound 1 produced exclusively the cis-chelate complex [PdCl2(1-κ2P,P’)], while the homologated ligand 2 afforded a complex mixture of compounds which equilibrated upon heating in methanol in favour of the symmetrical dimeric complex trans-[(μ-2)PdCl2]2 as a mixture of racemic and meso isomers. Notably, in aqueous Pd-catalysed cyanation of aryl bromides and Suzuki-Miyaura-type cross-coupling of benzoyl chlorides with boronic acids producing benzophenones, catalysts generated in situ from bis-phosphine 1 and Pd(II) sources were often more active than their counterparts resulting from dppf and 2.
C(acyl)-C(sp2) and C(sp2)-C(sp2) Suzuki-Miyaura cross-coupling reactions using nitrile-functionalized NHC palladium complexes
?akir, Sinem,Karabiyik, Hande,Kavukcu, Serdar Batikan,Rethinam, Senthil,Türkmen, Hayati
, p. 37684 - 37699 (2021/12/09)
Application of N-heterocyclic carbene (NHC) palladium complexes has been successful for the modulation of C-C coupling reactions. For this purpose, a series of azolium salts (1a-f) including benzothiazolium, benzimidazolium, and imidazolium, bearing a CN-substituted benzyl moiety, and their (NHC)2PdBr2 (2a-c) and PEPPSI-type palladium (3b-f) complexes have been systematically prepared to catalyse acylative Suzuki-Miyaura coupling reaction of acyl chlorides with arylboronic acids to form benzophenone derivatives in the presence of potassium carbonate as a base and to catalyse the traditional Suzuki-Miyaura coupling reaction of bromobenzene with arylboronic acids to form biaryls. All the synthesized compounds were fully characterized by Fourier Transform Infrared (FTIR), and 1H and 13C NMR spectroscopies. X-ray diffraction studies on single crystals of 3c, 3e and 3f prove the square planar geometry. Scanning Electron Microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), metal mapping analyses and thermal gravimetric analysis (TGA) were performed to get further insights into the mechanism of the Suzuki-Miyaura cross coupling reactions. Mechanistic studies have revealed that the stability and coordination of the complexes by the CN group are achieved by the removal of pyridine from the complex in catalytic cycles. The presence of the CN group in the (NHC)Pd complexes significantly increased the catalytic activities for both reactions.
Palladium-Catalyzed Aminocarbonylation of Aryl Halides with N,N-Dialkylformamide Acetals
Hirata, Shuichi,Osako, Takao,Uozumi, Yasuhiro
, (2021/10/05)
We developed a protocol for the palladium-catalyzed aminocarbonylation of aryl halides using less-toxic formamide acetals as bench-stable aminocarbonyl sources under neutral conditions. Various aryl (including heteroaryl) halides reacted with N,N-dialkylformamide acetals in the presence of a catalytic amount of tris(dibenzylideneacetone)dipalladium(0)-chloroform adduct and xantphos to give the corresponding aromatic carboxamides at 90–140 °C without any activating agents or bases in up to quantitative chemical yield. This protocol was applied to aryl bromides, aryl iodides, and trifluoromethanesulfonic acid, as well as to relatively less-reactive aryl chlorides. A wide range of functionalities on the aromatic ring of the substrates were tolerated under the aminocarbonylation conditions. The catalytic aminocarbonylation was used to prepare the insect repellent N,N-diethyl-3-methylbenzamide as well as a synthetic intermediate of the dihydrofolate reductase inhibitor triazinate.
