France, Oct. 7 -- Many molecules can exist in two mirror-image forms, but in nature only one form often predominates - a phenomenon known as homochirality. Chemists have long struggled to explain how this happens.

Kagan and Soai's discoveries helped show how chemical reactions can be steered towards one molecular form rather than the other, work that has proved important in fields including pharmaceutical manufacturing, the Nobel committee said.

"They have enabled chemists to drive chemical reactions that lead to homochirality," the jury added.

One area of this field, asymmetric catalysis, had already been recognised with a Nobel Prize in 2001.

Kagan, professor emeritus at Paris-Saclay University, was not among the recipients then des...