Karl Barry Sharpless

Karl Barry Sharpless (born April 28, 1941) is an American chemist. He is a two-time Nobel laureate in Chemistry known for his work on stereoselective reactions and click chemistry.

Sharpless developed stereoselective oxidation reactions, and showed that the formation of an inhibitor with femtomolar potency can be catalyzed by the enzyme acetylcholinesterase, beginning with an azide and an alkyne. He discovered several chemical reactions which have transformed asymmetric synthesis from science fiction to the relatively routine, including aminohydroxylation, dihydroxylation, and the Sharpless asymmetric epoxidation.

In 2001 he was awarded a half-share of the Nobel Prize in Chemistry for his work on chirally catalyzed oxidation reactions (Sharpless epoxidation, Sharpless asymmetric dihydroxylation, Sharpless oxyamination).

In 2002, he was elected as member of the European Academy of Engineering.

In 2019, Sharpless was awarded the Priestley medal, the American Chemical Society's highest honor, for "the invention of catalytic, asymmetric oxidation methods, the concept of click chemistry and development of the copper-catalyzed version of the azide-acetylene cycloaddition reaction.". He received the Gold Medal of the American Institute of Chemists in 2023.