N fmoc protected amino acids

1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate (HATU), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium fluorophosphate (HBTU) and N-Fmoc-protected amino acids were obtained from Iris Biotech GmbH. Piperidine, diisopropylcarbodiimide (DIC), N-hydroxybenzotriazole (HOBt), MPAA (97%, MPAA), 3-mercaptopropionic acid (MPA), tris(2-carboxyethyl)phosphine hydrochloride (≥98%, TCEP·HCl), thiophenol, triisopropylsilane (TIS), guanidine hydrochloride (≥99%, Gn·HCl), hydrochloric acid (reagent grade, 37%), and sodium hydroxide (pellets, 97%) as well as other reagents were purchased from Sigma Aldrich, Acros Organics or Merck and were of the purest grade available. Peptide synthesis grade N,N-dimethylformamide (DMF), dichloromethane, diethyl ether, acetonitrile, heptane, LC-MS-grade acetonitrile (0.1% TFA), LC-MS grade water (0.1% TFA), N,N-diisopropylethylamine (DIEA), acetic anhydride (Ac₂O), and trifluoroacetic acid (TFA) were purchased from Biosolve and Fisher-Chemical. NovaSyn TGR solid support was purchased from Sigma Aldrich. Bis(2-sulfenylethyl)amino trityl 1% divinylbenzene cross-linked polystyrene solid support (SEA PS) was produced on demand by Roowin. Solvents and reagents were used as received.

2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium fluorophosphate (HBTU) and N-Fmoc protected amino acids were obtained from Iris Biotech GmbH. 4-Mercaptophenylacetic acid (97%, MPAA), 3-mercaptopropionic acid (MPA), tris(2-carboxyethyl)phosphine hydrochloride (≥98%, TCEP), thiophenol, triisopropylsilane (TIS), guanidine hydrochloride (≥99%), sodium phosphate dibasic dihydrate (≥99%), hydrochloric acid (reagent grade, 37%), and sodium hydroxide (pellets, 97%) were purchased from Sigma-Aldrich. All other reagents were purchased from Acros Organics or Merck and were of the purest grade available. Peptide synthesis grade N,N-dimethylformamide, dichloromethane, diethylether, acetonitrile, heptane, LC–MS-grade acetonitrile (0.1% TFA), LC–MS-grade water (0.1% TFA), N,N-diisopropylethylamine (DIEA), and acetic anhydride were purchased from Biosolve and Fisher-Chemical. Trifluoroacetic acid (TFA) was obtained from Biosolve. Decane (synthesis grade) was purchased from Merck. Solvents and reagents were used as received. Water was purified with a Milli-Q UltraPure Water Purification System.