Direct Entry to Peptidyl Ketones via SmI<sub>2</sub>-Mediated C−C Bond Formation with Readily Accessible <i>N</i>-Peptidyl Oxazolidinones
作者:Tina Mittag、Kasper L. Christensen、Karl B. Lindsay、Niels Christian Nielsen、Troels Skrydstrup
DOI:10.1021/jo702286b
日期:2008.2.1
[GRAPHICS]In this work, a new method for the preparation of peptidyl ketones is presented employing a SmI2/H2O-mediated coupling of N-peptidyl oxazolidinones with electron-deficient alkenes. The requisite peptide imides were easily prepared by solution-phase peptide synthesis starting from an N-acyl oxazolidinone derivative of an amino acid. Importantly, they could be used directly in the C-C bond-forming step without the need for further functionalization. Coupling of these peptide derivatives with a second peptide possessing an N-terminal acryloyl group leads to ketomethylene isosteres of glycine-containing peptides. This method represents an alternative means for ligating two small peptides through a C-C bond-forming step.
Expanding the Scope of the Acyl-Type Radical Addition Reactions Promoted by SmI<sub>2</sub>
作者:Jakob Karaffa、Karl B. Lindsay、Troels Skrydstrup
DOI:10.1021/jo061299s
日期:2006.10.1
N-Acyl oxazolidinones of simple carboxylic acids and amino acids were observed to undergo successful SmI2-promoted couplings with substituted acrylamides and acrylates, affording a variety of functionalized γ-ketoamides and -esters with yields attaining 85%. As many of these reductive couplings were previously found to be ineffective employing the corresponding 4-pyridylthio esters, the applicability