Dawn Wong - Catalytic asymmetric synthesis of protected tryptophan regioisomers

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      Publication Details (including relevant citation   information):

      Carlier, P. R.; Lam, P. C.-H.; Wong, D. M.  Catalytic asymmetric synthesis of protected tryptophan   regioisomers.

      Journal of Organic Chemistry 2002, 67,   6256 -6259.

      PMID: 12182675. http://dx.doi.org/10.1021/jo025964i



      Tryptophan 1 (Trp) is superior to all other   naturally occurring peptide residues in its ability to bind   cations (the cation- 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.

      Address (URL): http://dx.doi.org/10.1021/jo025964i