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Primary Amine and Solvent-Induced Polymerizations of L- or D,L-Phenylalanine N-Carboxyanhydride

✍ Scribed by Hans R. Kricheldorf; Colin v. Lossow; Gert Schwarz

Publisher
John Wiley and Sons
Year
2005
Tongue
English
Weight
168 KB
Volume
206
Category
Article
ISSN
1022-1352

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✦ Synopsis

Abstract

Summary: Benzylamine, hexylamine and aniline‐initiated polymerizations of D,L‐phenylalanine and L‐phenylalanine N‐carboxyanhydride (D,L‐Phe‐NCA and L‐Phe‐NCA) were performed in various solvents. The isolated polypeptides were characterized by MALDI‐TOF mass spectroscopy. Exclusively linear polypeptides having one amide and one amino endgroup were found, when the polymerizations were conducted in a closed reaction vessel with dioxane or sulfolane as reaction media. Traces of water competed with aniline as initiator, when the reaction vessel was closed with a drying tube. In N,N‐dimethylformamide (DMF) formyl endgroups were formed at polymerization temperatures of 60 °C. In DMF and N‐methylpyrrolidone, cyclic oligo‐ and polypeptides were formed by a solvent‐induced polymerization initiated by zwitterions, which may compete with the primary amine‐initiated polymerizations.

MALDI‐TOF mass spectrum of a poly(D,L‐phenylalanine) polymerized in NMP without addition of an initiator.

magnified imageMALDI‐TOF mass spectrum of a poly(D,L‐phenylalanine) polymerized in NMP without addition of an initiator.

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