Improvement of the catalytic efficiency of Suzuki-Miyaura reaction depending on the numbering-up flow reactors

• The self-supporting catalyst of poly(bulky N-heterocyclic carbene) was prepared. • Its average molecular weight was greatly increased to improve its separability. • This catalyst showed excellent catalytic activity and stability in continuous flow reactor. • The catalytic efficiency was greatly improved depending on the numbering-up of reactors with a parallel connection. The increasing demands for the greener synthesis and the higher efficient strategy for the Suzuki–Miyaura reaction have motivated the development of new catalysts and processes due to its important application in pharmaceutics, petrochemicals, organic synthesis, polymer, etc. fields. In this work, different designs of numbering-up reactors were employed for the catalysis of Suzuki–Miyaura reaction based on a self-supporting palladium catalyst. Compared with the conventional tank reactor, the catalytic efficiency was improved more than 5 times depending on the numbering-up of reactors with a parallel connection. Furthermore, the influence of the different connection models on the catalysis was carefully compared. The high catalytic activity, good adaptability, and non-leakage of palladium bestowed upon this strategy with great potential in the large-scale application of the Suzuki-Miyaura reaction. Moreover, the synthesis of a self-supporting palladium catalyst (P(b-NHC-Pd)) with high molecular weight was presented. From the catalytic kinetics analysis, the activation energy of this catalyst decreased by 37% compared with that of tetrakis(triphenylphosphine)palladium. Thus, this self-supporting catalyst is highly promising for operation in a continuous flow reactor due to its high catalytic activity, excellent separability, and high stability. .