[GRAPHICS]Pure alpha -azido acids were prepared using an efficient diazo transfer method followed by buffered workup, These building blocks were used to prepare small peptides on Wang resin by two approaches, Peptides prone to diketopiperazine formation were prepared in good yields by coupling acids to resin bound iminophosphoranes during Fmoc-Wang synthesis, The iminophosphoranes can also be hydrolyzed under neutral conditions to provide unprotected amines ready for further coupling.
Orthogonally Protected Cyclo-β-tetrapeptides as Solid-Supported Scaffolds for the Synthesis of Glycoclusters
作者:Pasi Virta、Marika Karskela、Harri Lönnberg
DOI:10.1021/jo052348o
日期:2006.3.1
4-methyltrityl (Mtt) and 1-methyl-1-phenylethyl protections (PhiPr) exposes the β-amino and carboxyl terminus, respectively, and on-resin cyclization then gives the desired orthogonally protected cyclo-β-tetrapeptides (1 and 2). The α-amino groups, bearing the Fmoc and Alloc protections and the azide mask, allow stepwise orthogonal derivatization of these solid-supported cyclo-β-tetrapeptide cores (1 and 2). This
Solid-Phase Staudinger Ligation from a Novel Core-Shell-Type Resin: A Tool for Facile Condensation of Small Peptide Fragments
作者:Hanyoung Kim、Jin Ku Cho、Saburo Aimoto、Yoon-Sik Lee
DOI:10.1021/ol0530629
日期:2006.3.1
[reaction: see text] Solid-phase Staudinger ligation of small peptides was performed on a novel core-shell-type resin. Solid-phase Staudinger ligation was mediated by synthetic solid-supported phosphinothiol, which was readily prepared by a straightforward synthetic route. This protocol afforded final peptide products in excellent yields and purities and thus could provide the opportunity to facilitate