Polymer-Bound Triarylphosphine-Iodine Complexes, Convenient Coupling Reagent Systems in Peptide Synthesis

Abstract

N-protected α-amino acids are readily coupled with α-aminoacyl esters by polystyryl diphenylphosphine-iodine complex in very high yields and without detectable racemization. Protecting groups of general use for both amine and carboxyl functions, as well as the common side-chain-function protecting groups, are well tolerated under our experimental conditions. The workup is very easy since the only byproduct formed is a polymer-linked phosphine oxide that is simply filtered off to achieve the coupling product.