Journal of Organic Chemistry 2002-08-23

Catalytic asymmetric synthesis of protected tryptophan regioisomers.

Paul R Carlier, Polo C-H Lam, Dawn M Wong

文献索引：J. Org. Chem. 67 , 6256, (2002)

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摘要

Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-pi interaction). In an effort to expand the toolbox of Trp-like amino acids, in this note we report catalytic asymmetric syntheses of Trp regioisomers 2a-e, where the alanine unit is attached not to C-3 of indole but to C-2, C-4, C-5, C-6, or C-7. Excellent asymmetric induction is obtained in each case (generally >97% ee). Ab initio calculations suggest that the indole nuclei of 2a-e will bind Na(+) with the same affinity as that of Trp.