William S. Knowles

α-Amino acids by catalytic asymmetric hydrogenation

Abstract Over the past decade the field of asymmetric hydrogenation has proliferated. It is now one of the best understood catalytic reactions. Enantiomeric excesses greater than 95% can be achieved with α-acylaminoacrylic acids, amino acid precursors. Excellent enantioselectivity can also be obtained with other prochiral olefins.

Use of X-ray Crystal Structure in the Study of Asymmetric Catalysis

A considerable number of efficient asymmetric hydrogenation catalysts based on complexes of rhodium and a chiral bisphosphine have been reported. These are highly effective only on enamide precursors of α-amino acids or other closely related systems capable of chelating with the metal. Examination of x-ray crystal structures of the metal complexes has indicated that all these diverse structures may be working by a common mechanism.

Synthesis & characterization of N-amino-glyphosate as a potent analog inhibitor of E. coli EPSP synthase

Abstract All previous attempts to identify glyphosate analogs which retain their potency against the known biological target, EPSP synthase, have been unsuccessful. Consequently, the glyphosate binding site was thought to be extremely specific in this system. Here we report the novel N-amino glyphosate analog 3 as the first successful modification of the glyphosate skeleton which exhibits inhibitor properties comparable to glyphosate.