Microballs Containing Ni(0)Pd(0) Nanoparticles for Highly Selective Micellar Catalysis in Water

Abstract

Both Ni(0) complexes and nanoparticles (NPs) are unstable in water, which poses a significant hindrance to their application in aqueous synthetic catalysis. To overcome these barriers, ligated Ni(0) nanoparticles (diameter <1 nm) containing a minimum amount of Pd(0) in the microballs formed of amphiphile PS-750-M are developed and applied in the highly selective carbamate cleavage. Selectivity and functional group tolerance are thoroughly investigated. Control experiments revealed the importance of an individual component of the nanocatalyst. Use of our proline-based amphiphile PS-750-M is critical for achieving microball architecture, the stability of nanoparticles, and desired catalytic activity. Once formed, microballs can be isolated and stored at ambient temperature. Catalyst is thoroughly characterized by Xray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, thermogravimetric analysis, infrared, and cyclic voltammetry. For selective catalysis, zero oxidation state of both Ni and Pd is crucial. On the basis of catalyst characterization and control experiments, the plausible reaction mechanism is proposed.

Metal–Micelle Cooperativity: Phosphine Ligand-Free Ultrasmall Palladium(II) Nanoparticles for Oxidative Mizoroki–Heck-type Couplings in Water at Room Temperature

“…With our technology, these substrates react cleanly to afford desired products due to the very mild conditions. This transformation is functional group tolerant and is compatible with nitro (10,12,17,19,31) and reactive fluoro groups (3,18). The trifluoromethyl group was also well-tolerated (6, 9, 14, 21), as were substrates containing heterocyclic moieties, including benzofuranyl (8,24) and thiophenyl (11).…”

“…Water is a safe, stable, inexpensive, and naturally abundant solvent. , However, in organic synthesis, it is predominantly used for reaction work-ups rather than as an alternative solvent. − Nonetheless, it has many exciting features to offer better and cleaner chemistry for green chemical synthesis. − The very forward-thinking statement by Sheldon more than a decade ago, “the best solvent is no solvent, but if a solvent is needed, then water has a lot to recommend it”, has experimentally been proven correct for many areas of chemistry. ,− For example, micellar catalysis, a significant enabler of chemistry in water, has been applied to many diverse classes of organic chemistry reactions, often with improved reactivity and/or selectivity compared to their organic solvent enabled counterparts. − …”

Sustainability as a Trigger for Innovation!

“…[38] These conditions resulted in a broad substrate scope in a series of highly selective and sustainable cross-couplings transformations, such as Buchwald-Hartwig, Sonogashira or Suzuki-Miyaura (Scheme 9). [39]…”

Selective catalysis in a cellular microenvironment—a living cell catalytic system with intracellular nanopalladium for olefin hydrogenation

“…For example, nanopalladium is loaded into the pores of MOFs, [3][4][5][6][7][8][9][10][11][12] or into the channels of molecular sieves, [13][14][15] or into the apo-ferritin cage, 16 so as to form a selective catalytic system with the action of a carrier. [17][18][19] Although the selectivity of these catalytic systems did improve significantly, they struggle to compete with self-reproducible, green synthetic and recyclable biocatalysts. The living cell itself is a natural catalytic system, including the intracellular enzymes and the cell membrane.…”