Use of Base Metals in Suzuki Coupling
Mechanism + Description
Use of base metal complexes to replace Pd – mechanism as for Pd coupling
General comments
A number of precious and base metals have been reported to replace Pd in the Suzuki reaction. These include Ru, Ni, Fe and Cu. Nickel is probably the most studied replacement metal. Base metals are typically used at higher loadings than Pd metal complexes. This is adequately compensated for by their much lower cost, increased abundance, and lower life cycle impact.
A degree of caution needs to be exercised when working with base metals and other reaction conditions claiming to be 'metal free' since the Pd contamination of equipment, even at very low ppm levels, or other added inorganic reagents can produce an active catalyst for Suzuki reactions.
Key references
Relevant Scale-Up Examples with Scheme
Org. Process Res. Dev. 2013, 17, 97−107
Experimental
48 kg scale