Polymerization reaction with diphenylphosphoryl azide. Preparation of poly(α‐amino acid)s by direct polycondensation of α‐amino acids

Abstract

Polypeptides can be prepared by stirring an amino acid solution in the presence of diphenylphosphoryl azide (DPPA) and an adequate tertiary amine. Generally, 1,3 mol of DPPA and 2,3 mol of triethylamine per mol of amino acid gave the best result. Polymerization of various amino acids (Gly, Ala, Leu, Phe, Met, Glu(OBzl), Glu(OMe), Cys(Bzl), Ser(Bzl), His(Bzl), Lys(Z), Arg(Tos), Arg(N02), Arg(Mts), etc.; cf. Tab. 2) in dimethyl sulfoxide, N,N-dimethylformamide, 1,4-dioxane, pyridine, etc. gave the corresponding polypeptides with molecular weights as estimated from their intrinsic viscosities between 3 000 and 16000, in reasonable yields. The purity of the resulting polypeptides was confirmed by IR, elemental analysis and optical rotation measurements of their acid total hydrolysates.

A15N-1H dipolar CSA solid-state NMR study of polymorphous polyglycine (-CO-CD2-15NH-)n

“…The deuteration of the C a position was controlled with IR, Raman and NMR spectroscopy. The glycine was then polymerized in presence of diphenylphosphorylazide [53], following the procedure of the previous works [34,36]. PG I was obtained by evaporation of a solution in trifluoroacetic acid.…”

Controlled/living free‐radical copolymerization of 4‐(azidocarbonyl) phenyl methacrylate with methyl acrylate under 60Co γ‐ray irradiation

“…During the last decades, many acyl azide polymers have been synthesized to be used as the precursors of materials such as polyurethanes, polyureas, and polyamides. Nishi and coworkers4–9 prepared linear polyureas, polyurethanes, and polyamides by acyl azides. Okaniwa et al10 reported a novel one‐pot procedure for the synthesis of dendritic poly(amideurea)s via the Curtis reaction.…”

Synthesis of Copoly(amino acids) as Potential Biomaterials by Diphenyl Phosphoryl Azide

“…INTRODUCTION n a previous article [1], we reported on the direct homopolyconden-I sation of amino acids by the diphenyl phosphoryl azide (DPPA) method, which was proposed by Nishi and co-workers [2][3][4]. The polymerizations of ¡3-benzyl-L-aspartate (Asp.Bz) were carried out in the presence of DPPA and triethylamine (TEA).…”

“…The highest yield and molecular weight of the polymer were obtained from the polymerization at room temperature by using [ [1,3].…”

“…On the whole, a [DPPA]/ [Monomer] of 1.0-1.3 and a [TEA]/[Monomer] of 2.3-3.0 are favorable for Asp.Bz-Phe copolymerization. These observations are in agreement with those reported for the homopolycondensation of Asp.Bz[1] and other amino acids[3].Solvent studies were carried out for the copolymerization of Asp.BzPhe (1:1) using DMF, tetrahydrofuran (THF), dichloromethane (DCM), N,N'-dimethyl sulfoxide (DMSO), and pyridine (Pyr) as solvents…”