Stereoselective and Site-Specific Allylic Alkylation of Amino Acids and Small Peptides via a Pd/Cu Dual Catalysis
We report a stereoselective and site-specific allylic alkylation of Schiff base activated amino acids and small peptides via a Pd/Cu dual catalysis. A range of noncoded α,α-dialkyl α-amino acids were easily synthesized in high yields and with excellent enantioselectivities (up to >99% ee). Furthermore, a direct and highly stereoselective synthesis of small peptides with enantiopure α-alkyl or α,α-dialkyl α-amino acids residues incorporated at specific sites was accomplished using this dual catalyst system.
Conformations in the Solid State and Solubility Properties of Protected Homooligopeptides of Glycine and β-Alanine
IR spectroscopic conformational analyses of Boc-Glyn-OBzl (n=3-7) and Boc-(β-Ala)n-OBzl (n=3-8) were performed in the solid state, suggesting the occurrence of the β-sheet structure in the higher oligomers (n=5-8).Solubility data ind