On the role of metal contaminants in catalyses with FeCl3.

Metal catalysis has a dominant role in modern organic chemistry. In particular, crosscoupling reactions allow bond formations, which have previously been impossible to perform.[1] Precious metal catalysts dominate the field, but alternative systems based on nickel and copper salts have also, historically, been important. In particular, recent systems based on these metals have been described that provide products in a highly efficient manner.[2]