3D Printed Palladium Catalyst for Suzuki‐Miyaura Cross‐coupling Reactions

Abstract

Selective laser sintering (SLS) 3d printing was utilized to manufacture a solid catalyst for Suzuki-Miyaura cross-coupling reactions from polypropylene as a base material and palladium nanoparticles on silica (SilicaCat Pd 0 R815-100 by SiliCycle) as the catalytically active additive. The 3d printed catalyst showed similar activity to that of the pristine powdery commercial catalyst, but with improved practical recoverability and reduced leaching of palladium into solution. Recycling of the printed catalyst led to increase of the induction period of the reactions, attributed to the pseudo-homogeneous catalysis. The reaction is initiated by oxidative addition of aryl iodide to palladium nanoparticles, resulting in formation of soluble molecular species, which then act as the homogeneous catalyst. SLS 3d printing improves handling, overall practicality and recyclability of the catalyst without altering the chemical behaviour of the active component.

Recent Advances in 3D Printing of Structured Materials for Adsorption and Catalysis Applications

“…A relatively new style of 3D printing and comparable to polymer fiber wet-spinning processes, matrix incorporation is defined here as the suspension of the active material within an inert stabilizer. Here, it is worth drawing a distinction between adsorbents and catalysts, as the former has traditionally been suspended within an inert polymer matrix, such as torlon, , while the latter has been suspended in a silica or silicon carbide matrix. − Generally speaking, this type of printing has been used to enhance mechanical strength or overcome rheological limitations, such as in the cases of 3D-printed polymer/zeolites or polymer/MOFs, or to tune hierarchal porosity and active site accessibility, such as in the case of 3D-printed catalysts.…”

A tertiary phosphine oxide ligand-based recyclable system for the Suzuki–Miyaura and Negishi reactions: evidence for pseudo-homogeneous catalysis

“…27 A Suzuki–Miyaura reaction between 4-iodotoluene and phenylboronic acid was conducted under standard conditions and allowed to stir for three hours, the reaction was then filtered and allowed to stir for a further 21 hours (24 hours total). 28 From the precipitate, black palladium species were observable suggesting the formation of nanocomposites, surprisingly the reaction still proceeded to completion suggesting that even after filtration catalytically active Pd species remain present in solution ( i.e. homogenous reactivity).…”

An Imidazole‐Rich Pd(II)‐Polymer Pre‐catalyst for the Suzuki‐Miyaura Coupling: Stability Influenced by Dissolved Oxygen and Reactants Concentration

“…In principle, this could be attributed to an induction period where the catalytic species Pd(0) are formed as suggested for several Pd(II) pre-catalysts. [25,26,64] However, a different explanation is given. Although no protons are exchanged during the reaction, it is known that the base plays an important role in the SM reaction and is generally accepted that À OH ions can accelerate the transmetallation step.…”