Catalytic Asymmetric Synthesis of Protected Tryptophan Regioisomers
摘要:
Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-a 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.
Catalytic Asymmetric Synthesis of Protected Tryptophan Regioisomers
摘要:
Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-a 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.
ß-aryl and ß-vinyl-αß-didehydro-α-aminoacid derivatives through the palladium-catalysed reaction of aryl and vinyl triflates with methyl α-acetamidoacrylate
Catalytic Asymmetric Synthesis of Protected Tryptophan Regioisomers
作者:Paul R. Carlier、Polo C.-H. Lam、Dawn M. Wong
DOI:10.1021/jo025964i
日期:2002.8.1
Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-a 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.