Di‐μ‐Bromobis(tri‐ t ‐Butylphosphino)Dipalladium(I)

[185812-86-6]] C24H54Br2P2Pd2 (MW 777.28) InChI = 1S/2C12H27P.2BrH.2Pd/c2*1-10(2,3)13(11(4,5)6)12(7,8)9;;;;/h2*1-9H3;2*1H;;/q;;;;2*+1/p-2 InChIKey = TTXZLVYSSFAHEL-UHFFFAOYSA-L Physical Data: dark greenish blue microcrystals–color slightly varies depending on the crystalline nature and particle size. Solubility: soluble in THF, toluene, CH2Cl2, and CHCl3. Insoluble in alcohols. Commercial Availability: Johnson Matthey (multigram to kilogram–trade name Pd-113), Alfa Asear, and Strem for catalog quantities. Major Applications: cross-coupling catalysis, especially C–N/S coupling, Suzuki coupling, cyanation, α-arylation of ketones, esters, and amides, α-vinylation, and diasteroselective α-arylation. Synthesis: The original milligram to gram synthesis is reported in the literature with modest to moderate yield.1 Caution! scale-up using the reported procedures may result in poor quality or completely decomposed material. This might be due to the temperature and air sensitivity of the product in the solution phase. Characterization: 31P NMR: (δ) ppm: 87.0 in C6D6 1H NMR: (δ) ppm: 1.33 (singlet; upon expansion, it appears as a distorted triplet) in C6D6. Molecular Structure: the X-ray molecular structure is reported in the literature.1 Stability: sensitive to air and moisture. Compound in contact with oxygen forms an oxygen-inserted product with elimination of H2 (eq 1).2 (1) Applications in Organic Synthesis/Catalysis: from an academic and industrial perspective, [Pd(μ-Br)(t-Bu3P)]2, commonly known as Pd(I) dimer, is a unique coupling catalyst in terms of ease of activation, presumably to a highly active “12-electron Pd(0)” species, (t-Bu3P)Pd(0). Therefore, [Pd(μ-Br)(t-Bu3P)]2 is kinetically more active than the known “14-electron Pd(0)” catalyst, (t-Bu3P)2Pd(0), or the in situ Pd(0) catalyst formed by reacting Pd2dba3 with the pyrophoric t-Bu3P. The major applications are highlighted in the following.