88489-27-4

Upstream product

• 2666-93-5 (S)-Leu-OMe 
• 2480-93-5 Boc-Orn(Z)-OH 
• 7517-19-3 methyl (L)-leucinate hydrochloride 

Downstream Products

• 88489-29-6 H-L-Orn(Z)-L-Leu-OMe*TFA 
• 914955-67-2 Boc-D-Phe-ψ[(E)-C(CH3)=CH]-Ala-Val-Orn(Cbz)-Leu-OMe 

Relevant academic research and scientific papers

4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium Toluene-4-sulfonate (DMT/NMM/TsO?) Universal Coupling Reagent for Synthesis in Solution

4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TsO?), a representative member of the inexpensive and environmentally-friendly N-triazinylammonium family of sulfonates, has been found to be a very effective coupling reagent for the synthesis of amides, esters and peptides in solution. This study confirms the usefulness of DMT/NMM/TsO? for peptide synthesis in solution, starting from Z-, Fmoc-, and Boc-protected substrates as well as unnatural building blocks. Peptide synthesis with DMT/NMM/TsO? produced high yields, with high crude product purity and low risk of racemization. In all cases, stoichiometric amounts of reagents were used and the standard synthetic procedure, without the need for time-consuming optimization stages or expensive chromatographic purification. DMT/NMM/TsO? was also found to be very useful for the synthesis of oligopeptides using a fragment coupling strategy.

Trisubstituted (E)-alkene dipeptide isosteres as β-turn promoters in the gramicidin S cyclodecapeptide scaffold

(Chemical Equation Presented) A concise synthesis of a gramicidin S analogue with trisubstituted (E)-alkene dipeptide isostere (TEADI) replacements at both D-Phe-Pro positions was realized. Conformational analysis demonstrated that TEADIs can serve as typ

N-triazinylammonium tetrafluoroborates. A new generation of efficient coupling reagents useful for peptide synthesis

A new generation of triazine-based coupling reagents (TBCRs), designed according to the concept of "superactive esters", was obtained by treatment of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) chloride with lithium or silver tetrafluoroborate. The structure of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium tetrafluoroborate was confirmed by X-ray diffraction. Activation of carboxylic acids by using this reagent proceeds via triazine "superactive ester". The coupling reagent was successfully used for the synthesis of Z-, Boc-, and Fmoc-protected dipeptides derived from natural and unnatural sterically hindered amino acids and for fragment condensation, in 80-100% yield and with high enantiomeric purity. The manual SPPS of the ACP(65-74) peptide fragment (H-Val-Gln-Ala-Ala- lle-Asp-Tyr-Ile-Asn-Gly-OH) proceeded significantly faster than with TBTU or HATU, as well as the automated SPPS of the same fragment gave a purer product than by using TBTU or PyBOP. The reagent was also demonstrated to be efficient in on-resin head-to-tail cyclization of constrained cyclopeptides, in SPPS synthesis of Aib peptides, and in the synthesis of esters from appropriate acids, alcohols, and phenols. The high efficiency and versatility of this new generation of TBCRs confirm, for the first time, the usefulness of the concept of "superactive esters" in rational design of the structure of coupling reagents.

Facile synthesis of (2R,3R)-phenylalanine-2,3-d2 and NMR study on deuterated gramicidin S1)

(2R,3R)-Phenylalanine-2,3-d2 (D-Phe(*)) was synthesized through catalytic reduction of cyclo-(Z)-2,3-dehydrophenylalanyl-D-alanyl-) under an atmosphere of 2H2 and successive acid hydrolysis in the yield of 80% in high chiral induction. The D-Phe* thus obtained was used for synthesis of [D-Phe *4,4'] gramidicin S (GS*) gramidicin S (GS*). The 1H NMR spectrum of GS* in DMSO-d6 showed a sharp singlet at 2.98 ppm for the (3S)-proton of D-Phe* residue. It has been proposed that among rotamers of D-Phe aromatic side chain in GS the one with κ1 = 180° is predominant. The present observation provides sound evidence for assignments of D-Phe β-protons based on the proposal. (2R,3R)-phenylalanine-2,3-d//2 (d-Phe*) was synthesized through catalytic reduction of cyclo(-(Z)-2,3-dehydrophenylalanyl-D-alanyl-) under an atmosphere of **2H//2 and successive acid hydrolysis in the yield of 80% in high chiral induction. The D-Phe* thus obtained was used for synthesis of left bracket D-Phe***4**,**4** prime right bracket gramicidin S (GS*). The **1H NMR spectrum of GS* in DMSO-d//6 showed a sharp singlet at 2. 98 ppm for the (3S)-proton of D-Phe* residue. It has been proposed that among rotamers of D-Phe aromatic side chain in GS the one with // kappa //1 equals 180 degree is predominant. The present observation provides sound evidence for assignments of D-Phe beta -protons based on the proposal.

FACILE SYNTHESIS OF (2R,3R)-PHENYLALANINE -2,3-d2 AND ITS APPLICATION TO CONFORMATIONAL ANALYSIS OF GRAMICIDIN S

(2R,3R)-Phenylalanine-2,3-d2 was synthesized in a good yield through catalytic reduction of cyclo(-2,3-dehydrophenylalanyl-D-alanyl-) under an atmosphere of 2H2 and successive acid hydrolysis, and the amino acid was used t