Mechanistic Insight into the Nickel‐Catalyzed Cross‐Coupling of Aryl Phosphates with Arylboronic Acids: Potassium Phosphate is Not a Spectator Base but is Involved in the Transmetalation Step in the Suzuki–Miyaura Reaction

Abstract

Spectator or actor? Density functional theory calculations were performed to examine the role of the base in the nickel‐catalyzed cross‐coupling of aryl phosphates with arylboronic acids. Potassium phosphate was found to not act as a spectator base but was involved in the transmetalation step, as shown by a lower barrier than that of a base‐free process, owing to the activation of the carbonboron bond by the base. Further experimental observations support the theoretical findings.

Decarbonylative organoboron cross-coupling of esters by nickel catalysis

“…At first, Na 2 CO 3 reacts with the oxidative addition intermediate C with almost no energy barrier, and leads to the formation of the unprecedented Ni-[NaCO 3 NaOPh] cluster complex D ( Fig. 2b ) 24 25 35 36 37 . Overall reaction, C +Na 2 CO 3 → D , is found to be exergonic by 22.2 kcal mol −1 .…”

Highly bulky and stable geometry-constrained iminopyridines: Synthesis, structure and application in Pd-catalyzed Suzuki coupling of aryl chlorides

“…We noticed that water could promote the conversion of chlorobenzene to 62% which might be due to the better solubility of the base in toluene/H 2 O (2.5:1) mixed solvents ( Table 3 , entry 1). Bases have been proven to play an important role in Suzuki coupling reactions [ 74 ]. Then, in mixed solvents, various bases were examined ( Table 3 , entries 1–10).…”

A Green Alternative for the Conversion of Arylboronic Acids/Esters into Phenols Promoted by a Reducing Agent, Sodium Sulfite

“…Phosphate anion is able to coordinate to arylboronic acids, the former and the latter act as Lewis's base and acid respectively. This complex improves the leaving character of the boronic group . Within the scope of this study, a new modification was developed by the addition of K 3 PO 4 in the reaction.…”