| Abstract
| - A pyridoxamine equivalent, 9-aminothioxanthene 10,10-dioxide, has been designed that is capableof affording transamination in good to excellent yields of natural as well as artificial amino acids.Amidines and guanidines in catalytic amounts were capable of performing [1,3]-proton transfer inthe imines under mild conditions, whereas various simple amines failed. The use of chiral catalystsresulted in modest asymmetric induction (ee ≤ 45%). The electronic dependence in para-substitutedphenyl glyoxylate imines, isotope effects, and computational studies support a stepwise, bifunctionalmechanism for amidine and guanidine catalysts. Attempts toward an autocatalytic model systemare described.
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