Atom-Efficient, Palladium-Catalyzed Stille Coupling Reactions of Tetraphenylstannane with Aryl Iodides or Aryl Bromides in Polyethylene Glycol 400 (PEG-400)

Recent advances in transition metal-catalysed cross-coupling of (hetero)aryl halides and analogues under ligand-free conditions

The formation of new bonds is pivotal in organic chemistry and a prerequisite to life because it allows the construction of complex molecules from simple precursors.

A Highly Efficient and Recyclable Pd(Pph3)4/Peg-400 System for Stille Cross-Coupling Reactions of Organostannanes with Aryl Bromides

Pd(PPh3)4 in PEG-400 is shown to be a highly efficient catalyst for the Stille cross-coupling reactions of various organotin compounds with aryl bromides. The reaction could be conducted at 80 °C using NaOAc as base, yielding a variety of biaryls, alkynes and alkenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and the Pd(PPh3)4/PEG-400 system could be easily recycled and reused five times without any significant loss of activity.

A Highly Efficient and Reusable Palladium(II)/Cationic 2,2'-Bipyridyl-Catalyzed Stille Coupling in Water

A water-soluble PdCl₂(NH₃)₂/cationic 2,2'-bipyridyl system was found to be a highly efficient catalyst for Stille coupling of aryl iodides and bromides with organostannanes. The coupling reaction was conducted at 110 °C in water, under aerobic conditions, in the presence of NaHCO₃ as a base to afford corresponding Stille coupling products in good to high yields. When aryltributylstannanes were employed, the reactions proceeded smoothly under a very low catalyst loading (as little as 0.0001 mol %). After simple extraction, the residual aqueous phase could be reused in subsequent runs, making this Stille coupling economical. In the case of tetramethylstannane, however, a greater catalyst loading (1 mol %) and the use of tetraethylammonium iodide as a phase-transfer agent were required in order to obtain satisfactory yields.

Microwave-Assisted Stille Cross-Coupling Reaction Catalysed by in Situ Formed Palladium Nanoparticles

The Stille coupling of organotin compounds with aryl iodides and aryl bromides catalysed by in situ formed nanoparticles from commercially available palladium dichloride in PEG-400 in the presence of DMAP under microwave irradiation has been developed. For tetraphenylstannane, the reaction was carried out in an atom-efficient way, as 4 equiv. of aryl halides coupled effectively with 1 equiv. of tetraphenylstannane to furnish 4 equiv. of the corresponding functionalised biaryls in high yields. Under the same conditions, PhSnBu3 also reacted with aryl halides to produce biphenyls.

The palladium(ii) complex of N,N-diethyl-1-ferrocenyl-3-thiabutanamine: synthesis, solution and solid state structure and catalytic activity in Suzuki–Miyaura reaction

A novel phosphine-free ferrocene-containing Pd complex is an excellent precatalyst for Suzuki–Miyaura coupling.

Bi-functionalized PEG1000 ionic liquid [Imim-PEG1000-TEMPO][CuCl2−]: an efficient and reusable catalytic system for solvent-free aerobic oxidation of alcohols

A reusable catalytic system for efficient aerobic oxidation of alcohols with bi-functionalized PEG₁₀₀₀ ionic liquid [Imim-PEG₁₀₀₀-TEMPO][CuCl₂⁻] was described.

Suzuki-Miyaura reactions catalyzed by C₂-symmetric Pd-multi-dentate N-heterocyclic carbene complexes

Suzuki-Miyaura coupling reactions are promoted by Pd complexes ligated with C₂-symmetric multi-dentate N-heterocyclic carbenes derived in situ from Pd(OAc)₂ and imidazolium salts. Good to excellent yields were obtained for aryl bromides as substrates. Turnover numbers of up to 10⁵ could be achieved with 5 × 10⁻⁴ mol% of Pd(OAc)₂/1 × 10⁻³ mol% NHC precatalyst in 24 h.