223674-40-6

Upstream product

• 17498-50-9 L-valine hydrochloride 
• 86123-10-6 Fmoc-D-Phe-OH 
• 72-18-4 L-valine 
• 84890-98-2 Fmoc-Phe-O-COO-isoBu 
• 35661-40-6 N-Fmoc L-Phe 
• 103321-57-9 2S-flouren-9-ylmethoxycarbonylamino-3-phenylpropionyl chloride 
• 6306-52-1 L-valine methylester hydrochloride 
• 827018-98-4 Fmoc-Phe-Val-OMe 

Relevant academic research and scientific papers

Site-selective C(sp3)-H functionalization of di-, tri-, and tetrapeptides at the N-terminus

Although the syntheses of novel and diverse peptides rely mainly on traditional coupling using unnatural amino acids, postsynthetic modification of peptides could provide a complementary method for the preparation of nonproteinogenic peptides. Site select

α-N-Protected dipeptide acids: A simple and efficient synthesis via the easily accessible mixed anhydride method using free amino acids in DMSO and tetrabutylammonium hydroxide

The importance of dipeptides both in medicinal and pharmacological fields is well documented and many efforts have been made to find simple and efficient methods for their synthesis. For this reason, we have investigated the synthesis of α-N-protected dipeptide acids by reacting the easily accessible mixed anhydride of α-N-protected amino acids with free amino acids under different reaction conditions. The combination of TBA-OH and DMSO has been found to be the best to overcome the low solubility of amino acids in organic solvents. Under these experimental conditions, the homogeneous phase condensation reaction occurs rapidly and without detectable epimerization. The present method is also applicable to side-chain unprotected Tyr, Trp, Glu, and Asp but not Lys. This latter residue is able to engage two molecules of mixed anhydride giving the corresponding isotripeptide. Moreover, the applicability of this protocol for the synthesis of tri- and tetrapeptides has been tested. This approach reduces the need for protecting groups, is cost effective, scalable, and yields dipeptide acids that can be used as building blocks in the synthesis of larger peptides.

Convenient peptide synthesis without protection of C-Terminals

Condensation of carboxylic acids 1 and 5 with unprotected α-amino acids 2 via activation by ethyl chloroformate and triethylamine proceeded effectively to afford the corresponding amides in 5099% yields. Tripeptide 7c was obtained in 42% yield from the dipeptide 6c in a similar manner.

Alternative and chemoselective deprotection of the α-amino and carboxy functions of N-Fmoc-amino acid and N-Fmoc-dipeptide methyl esters by modulation of the molar ratio in the AlCl3/N,N-dimethylaniline reagent system

The amino and carboxy functions in N-Fmoc-α-amino acid and N-Fmoc-peptide methyl esters can be alternatively and chemoselectively deprotected by treatment with the reagent system AlCl3/N,N- dimethylaniline (DMA). The chemoselectivity of the process is controlled by modulating the relative molar ratio of the Lewis acid and DMA. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.