Structurally Diverse Bench-Stable Nickel(0) Pre-Catalysts: A Practical Toolkit for In Situ Ligation Protocols

Area of Science:

• Organometallic Chemistry
• Catalysis
• Organic Synthesis

Background:

• Nickel catalysis is a rapidly growing field in organic synthesis.
• Development of well-defined nickel precatalysts is crucial for advancing this area.
• Bench-stable and reactive nickel complexes are highly sought after.

Purpose of the Study:

• To synthesize and characterize novel, bench-stable, 18-electron, zero-valent nickel-olefin complexes.
• To investigate the structural, bonding, and electronic properties of these complexes.
• To evaluate their efficacy as precatalysts in various nickel-catalyzed reactions.

Main Methods:

• Synthesis of Ni(COD)(L) complexes where L = quinone, cyclopentadienone, thiophene-S-oxide, and fulvene.
• Characterization using NMR, IR, single-crystal X-ray diffraction, cyclic voltammetry, and TGA.
• Computational analysis including Natural Bond Orbital (NBO) analysis.

Main Results:

• Ten novel, bench-stable, 18-electron, zero-valent nickel-olefin complexes were successfully prepared.
• Detailed structural, bonding, and electronic properties were elucidated through comprehensive characterization.
• The complexes demonstrated competence as precatalysts in diverse nickel-catalyzed transformations.

Conclusions:

• The synthesized nickel-olefin complexes represent a valuable toolkit of precatalysts for organic synthesis.
• Their bench stability and tunable reactivity offer significant advantages for various catalytic applications.
• This work expands the scope of accessible nickel precatalysts, facilitating further innovation in catalysis.