Reusable Palladium N-Heterocyclic Tetracarbene for Aqueous Suzuki–Miyaura Cross-Coupling Reaction: Homogeneous Catalysis and Heterogeneous Recovery

Abstract

A pH-responsive Pd(II) N-heterocyclic tetracarbene complex synthesized by a solvothermal method was reported. It can be a highly active reusable catalyst to homogeneously catalyze the Suzuki−Miyaura cross-coupling reaction in water and can be heterogeneously recovered by simply adjusting the pH value of the aqueous reaction media.

Chelating Bis(N‐Heterocyclic Carbene) Palladium‐Catalyzed Reactions

“…An air-a nd moisture-stable monopalladium tetra(NHC) complex, 97 (Figure 16), was prepared by Dong and co-workers from Pd-bis(NHC) precursor under solvothermal conditions. [65] Apart from good activity for ab road substrate scope in aqueous-phase Suzuki-Miyaurar eactions, the recovery and reusability of 97 was highlighted. The complex was soluble in basic reaction media and could be recovered by adjusting the pH to pH 5b yu sing dilute HCl (2 mol L À1 ).…”

“…An air‐ and moisture‐stable monopalladium tetra(NHC) complex, 97 (Figure ), was prepared by Dong and co‐workers from Pd–bis(NHC) precursor under solvothermal conditions . Apart from good activity for a broad substrate scope in aqueous‐phase Suzuki–Miyaura reactions, the recovery and reusability of 97 was highlighted.…”

Application of Biaryl Phosphacycles in Palladium‐Catalysed Suzuki‐Miyaura Cross‐Coupling Reactions of Aryl Chlorides

“…13 C NMR (101 MHz, CDCl 3 ) δ =192.51, 146.00, 137.75, 133.71, 133.63, 130.82, 130.15, 128.80, 128.48, 128.17, 127.82, 127.59, 127.19. 2‐Trifluoromethyl‐biphenyl [94] . 1 H NMR (500 MHz, CDCl 3 ) δ =7.75 (d, J =7.8 Hz, 1H), 7.55 (t, J =7.5 Hz, 1H), 7.46 (t, J =7.6 Hz, 1H), 7.42–7.32 (m, 6H).…”

Heterogeneous catalysis by ultra-small bimetallic nanoparticles surpassing homogeneous catalysis for carbon–carbon bond forming reactions

“…11 To address these challenges, there has been great interest in designing cost-effective heterogeneous catalysts to allow for catalyst isolation and recycling without compromising catalytic activity. 9,12,13 Given the indispensable role of the Suzuki crosscoupling (SCC) reaction in organic synthesis and its simplicity and effectiveness, intense efforts have been directed toward the development of cost-effective heterogeneous catalysts. 3 However, the heterogeneous catalysis mechanism is still a matter of debate.…”