101697-56-7Relevant academic research and scientific papers
Peptide Synthesis by Prior Thiol Capture. 1. A Convenient Synthesis of 4-Hydroxy-6-mercaptodibenzofuran and Novel Solid-Phase Synthesis of Peptide-Derived 4-(Acyloxy)-6-mercaptodibenzofurans
Kemp, D. S.,Galakatos, Nicholas George
, p. 1821 - 1829 (2007/10/02)
Peptide bond formation by intramolecular acyl transfer across a rigid template is outlined.The template precursor 6-hydroxy-4-mercaptodibenzofuran (3) is obtained from 4-methoxydibenzofuran by metalation with n-butyllithium, oxidation with elemental sulfur, and demethylation.Routes to 4-(acyloxy)-6-mercaptodibenzofurans 4 are reported.Esters 4 derived from simple urethane N-blocked α-amino acids are conveniently prepared by direct acylation of 6-hydroxy-4-(methoxycarbonyldithio)dibenzofuran (12), followed by reduction with tri-n-butylphosphine.Esters 4 derived from the C-terminal carboxyl groups of peptides are prepared by a novel variant of conventional solid-phase peptide synthesis in which the chain elongation steps are carried out on the 4-((α-aminoacyl)oxy)-6-dibenzo-furanyldithio function linked through the disulfide to a polymeric support.At the completion of the elongation steps, release of 4 from the resin is achieved by reduction of the disulfide bond with tri-n-butylphosphine.
Peptide Synthesis by Prior Thiol Capture. 2. Design of Templates for Intramolecular O,N-Acyl Transfer. 4,6-Disubstituted Dibenzofurans as Optimal Spacing Elements
Kemp, D. S.,Galakatos, Nicholas G.,Bowen, Benjamin,Tan, Kenneth
, p. 1829 - 1838 (2007/10/02)
A central feature of the strategy for amide bond formation by prior thiol capture is an intramolecular acyl transfer across a template that links the phenolic ester function of one peptide with an unsymmetrical disulfide involving the side chain of the N-terminal cysteine residue of a second peptide.The structures of the 4-hydroxy-6-mercaptodibenzofuran (3) and 4-hydroxy-6-mercaptophenoxythiin (4) are established by 1H NMR spectra of deuterated dibenzofuran and phenoxythiin derivatives.On the basis of the criterion of effective molarity, a dibenzofuran template for intramolecular acyl transfer is shown to be approximately 2 orders of magnitude more efficient than a phenoxythiin.An effective local concentration of ca. 5 M and a Hammett ρ value of 2.6 are observed for the intramolecular acyl-transfer reaction 1 -> 2.
Peptide Synthesis by Prior Thiol Capture. 4. Amide Bond Formation: The Effect of Side-Chain Substituent on the Rates of Intramolecular O,N-Acyl Transfer
Kemp, D. S.,Galakatos, Nicholas G.,Dranginis, Stanley,Ashton, Christopher,Fotouhi, Nader,Curran, Timothy P.
, p. 3320 - 3324 (2007/10/02)
The effects of varying steric bulk of the side chain substituent of the acylating agent on rate of the amide bond forming step of the dibenzofuran-based thiol capture strategy were determined from rates of intramolecular isomerization of methyl S-4-(N-be
