The 2005 Bower Award in science presented to Henri B. Kagan

Abstract

The scientific theme for the 2005 Bower Award was Chemistry, specifically the field of Catalysis. The Franklin Institute, Philadelphia, Pennsylvania, awarded the 2005 Bower Award and Prize for achievement in Science to Henri B. Kagan for his seminal discovery of fundamental chemical principles that explain the impact of catalyst shape on its effectiveness in controlling chemical reactions, thus greatly simplifying the manufacture of pharmaceutically important compounds. Henri Kagan is widely recognized as a pioneer in the field of asymmetric catalysis. Starting in the early 1970s, his reports of the synthesis of the chiral bidentate diphosphine ligand and the demonstration of its use with soluble rhodium compounds to catalyze the efficient production of large enantiomeric excesses of chiral molecules in asymmetric hydrogenations has had far reaching effects on research in the field asymmetric catalysis. The concept of using chiral bidentate ligands of C2 symmetry has led the way for numerous developments in asymmetric catalysis. Later in 1986 his introduction of the concept and investigations into “nonlinear effects in asymmetric synthesis” using catalysts with chiral ligands that were not optically pure challenged the widely accepted assumption that the enantiomeric excess which is possible correlates linearly with the optical purity of the chiral ligands. He reported the first example in asymmetric catalysis where the optical purity of the product significantly exceeded the optical purity of the chiral ligand.