C-C bond formation catalyzed heterogeneously by nickel-on-graphite (Ni/Cg)

Area of Science:

• * Inorganic Chemistry
• * Organic Synthesis
• * Catalysis

Background:

• * Transition metal catalysis is crucial for forming carbon-carbon bonds.
• * Nickel catalysts offer a cost-effective alternative to precious metals.
• * Heterogeneous catalysts are desirable for ease of separation and recycling.

Purpose of the Study:

• * To investigate the catalytic activity of nickel(II) on graphite (Ni/Cg) for cross-coupling reactions.
• * To compare the performance and chemoselectivity of Ni/Cg with nickel on charcoal (Ni/C).
• * To explore the potential of Ni/Cg as an efficient heterogeneous catalyst.

Main Methods:

• * Preparation and activation of nickel(II) on graphite (Ni/Cg) catalyst.
• * Heterogeneous catalytic cross-coupling reactions using aryl halides/tosylates with various organometallic reagents (boronic acids, vinylalanes, vinylzirconocenes).
• * Comparative analysis of Ni/Cg and Ni/C catalysts, including assessment of chemoselectivity.

Main Results:

• * Ni/Cg demonstrates effective heterogeneous catalysis for cross-coupling reactions.
• * The study uncovered unusual chemoselectivities when comparing Ni/Cg with the Ni/C analogue.
• * Both catalysts facilitate couplings with aryl halides/tosylates and diverse nucleophiles.

Conclusions:

• * Inexpensive Ni/Cg is a viable and easily activated heterogeneous catalyst for cross-coupling.
• * Significant differences in chemoselectivity exist between Ni/Cg and Ni/C, offering distinct synthetic opportunities.
• * Ni/Cg presents a promising alternative for sustainable and efficient cross-coupling catalysis.