“Endangered” Palladium Palladacycles at the ppm level to the rescue
FARBOD A. MOGHADAM, OLIVIA C. LANGNER, BRUCE H. LIPSHUTZ*
*Corresponding author
Department of Chemistry & Biochemistry, University of California, Santa Barbara, USA
Abstract
The world of chemistry is starting to face the inevitable shortage of palladium, the most extensively used transition metal for catalysis in organic synthesis. Rather than searching indefinitely and at great expense for alternative metals that effect the same bond formations, there is another, much more promising approach: develop new technologies that feature Pd catalysis at the ppm level. Such technologies would facilitate bond-forming reactions that are “faster, better, and cheaper”; that offer greater levels of selectivity; and that happen under far milder reaction conditions in the absence of organic solvents. There’s one solution already in hand that meets all of these criteria while respecting the environment: …enter palladacycles, engineered to match the new rules for doing chemistry in water.
Endangered palladium? What does that mean? Are we running out? When did this happen? This can’t be.
Sound familiar? Is this anything close to how you would respond to news that we chemists are contributing at an alarming rate to the world’s shortage of palladium, a precious metal that plays such a huge role in modern catalysis? Can anyone imagine the day when we no longer have enough to assist in the making of pharmaceuticals that save lives every day or that’s required en route to agrochemicals that enable the world to feed its growing population? It’s going to happen… we are going to run out of available Pd, and if not in our or our children’s lifetimes, then, for sure, it is our grandchildren and beyond who will suffer the consequences. It’s not a matter of if but when. Can we live today with this clear understanding of what’s to come tomorrow?
THE PROBLEM
The “endangered” status of palladium has not arisen because we are consuming all of this metal that exists on earth; quite the contrary! The earth is blessed with a virtually unlimited amount of all ...
