Continuous Flow Synthesis of Metal-NHC Complexes*.

Area of Science:

• Organometallic Chemistry
• Sustainable Synthesis
• Flow Chemistry

Background:

• Late-transition metal complexes are vital in catalysis, medicinal chemistry, and materials science.
• Sustainable and mild synthetic routes are highly desirable for preparing these valuable compounds.
• Current methods often require harsh conditions or less environmentally friendly solvents.

Purpose of the Study:

• To report a continuous flow preparation of copper (Cu^I), gold (Au^I), and palladium (Pd^II) N-heterocyclic carbene (NHC) complexes.
• To demonstrate a sustainable and mild synthetic approach using readily available reagents.
• To showcase the scalability of the developed flow process.

Main Methods:

• Utilized cuprate, aurate, and palladate species in a continuous flow reactor.
• Employed technical grade acetone as the reaction solvent.
• Investigated reactions under extremely mild conditions.

Main Results:

• Successfully synthesized Cu^I, Au^I, and Pd^II-NHC complexes via continuous flow.
• All reactions proceeded efficiently under mild conditions.
• Demonstrated the scalability with a multigram-scale synthesis of [Cu(IPr)Cl].

Conclusions:

• Continuous flow synthesis offers a sustainable and attractive method for preparing late-transition metal-NHC complexes.
• The developed process is efficient, mild, and scalable, utilizing common solvents.
• This approach facilitates access to important metal complexes for various applications.