The addition of aryl halides to tetrakis(triphenylphosphine)palladium(0)

Kinetic Data for the Transmetalation/Reductive Elimination in Palladium‐Catalyzed Suzuki–Miyaura Reactions: Unexpected Triple Role of Hydroxide Ions Used as Base

“…Indeed, the exact positions of the two equilibria that regulate the ratios (1 Z,Br ; Z = CN, F, H), [10] and the dimeric complex…”

“…(Z = H, OMe) obtained during our mechanistic work on the palladium-catalyzed homocoupling of arylboronic acids in the presence of dioxygen, [9] and in the absence of any kinetic data on the transmetalation step in the literature, we decided to investigate the kinetics of the reaction of arylboronic acids Ar'B(OH) 2 with isolated trans-[ArPdXA C H T U N G T R E N N U N G (PPh 3 ) 2 ] complexes (X = I, Br, Cl) [10] in the presence of a base such as OH À . The investigations presented and discussed in the present work have been performed not under stoichiometric conditions of reagents with respect to trans-[ArPdXA C H T U N G T R E N N U N G (PPh 3 ) 2 ] complexes, but always in the presence of large excesses of Ar'B(OH) 2 (from 10 to 30 equiv) and base, to mimic the catalytic reaction conditions (from 10 to 3.3 mol % catalyst, respectively).…”

Pushing the Synthetic Limit: Polyphenylene Dendrimers with “Exploded” Branching Units—22‐nm‐Diameter, Monodisperse, Stiff Macromolecules

“…The cycle was repeated to obtain 4-bromo-4''-iodo-2,5-dimethyl-1,1':4',1''-terphenyl (4). The aryl iodide was treated with trimethylsilylacetylene under Sonogashira/ Hagihara conditions [13] to afford 5. The final step was the twofold Suzuki coupling of the remaining aryl bromide with 3,4-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-2,5-diphenylcyclopentadienone to furnish 6.…”

Dual Effect of Halides in the Stille Reaction: In Situ Halide Metathesis and Catalyst Stabilization

“…For 4 a a substantially faster transmetallation rate was observed than for 4 b, supporting our hypothesis ( Figure S2 in the Supporting Information). [14] The similar behavior of phenyl complexes [Pd II X(Ph)-A C H T U N G T R E N N U N G (PPh 3 ) 2 ] (6 a: X= Cl; 6 b: X= I) [15] (6 a more reactive than 6 b, see Figure S4 …”