Did you know that more than half of the drugs currently in use are chiral, potentially resulting in two different responses in the body? Chiral compounds are pairs of molecules that are mirror images of each other, just like a person’s right and left hand. Since the body interacts with each molecule differently, a chiral drug may produce the desired effects from one molecule, along with an unwanted side effect from its mirror image. It would be much safer and more efficient to make pure compounds without forming their unnecessary mirrored versions that only go to waste, but such selective synthesis has remained one of the most difficult challenges in drug discovery.