118474-95-6

Upstream product

• 10065-72-2 L-Alanine methyl ester 
• 103321-57-9 2S-flouren-9-ylmethoxycarbonylamino-3-phenylpropionyl chloride 
• 126727-04-6 2-(9-fluorenylmethoxycarbonylamino)-3-phenylpropionic acid 
• 2491-20-5 L-alanine methyl ester hydrochloride 
• 35661-40-6 N-Fmoc L-Phe 
• 1359014-85-9 N-Fmoc-Phe-SPh 
• 29022-11-5 N-(fluoren-9-ylmethoxycarbonyl)glycine 
• 93644-94-1 (S)-methyl 2-(1H-imidazole-1-carboxamido)propanoate 
• 1436573-47-5 N-fmoc-L-phenylalanyl-N-methyl-4-nitrobenzenesulfonamide 

Downstream Products

• 118474-96-7 {(S)-1-[((S)-2-Hydroxy-1-methyl-ethylamino)-methyl]-2-phenyl-ethyl}-carbamic acid 9H-fluoren-9-ylmethyl ester 
• 189455-66-1 Fmoc-Phe-Ala-OH 
• 1349173-20-1 Fmoc-Phe-D-Ala-OSu 
• 1349173-19-8 Fmoc-Phe-Ala-OSu 

Relevant academic research and scientific papers

Eco-friendly synthesis of peptides using fmoc-amino acid chlorides as coupling agent under biphasic condition

Background: Agro-waste derived solvent media act as a greener process for the peptide bond formation using Nα-Fmoc-amino acid chloride and amino acid ester salt with in situ neutralization and coupling under biphasic condition. The Fmoc-amino acid chlorides are prepared by the reported procedure of freshly distilled SOCl2 with dry CH2Cl2. The protocol found many added ad-vantages such as neutralization of amino acid ester salt and not required additional base for the neu-tralization, and directly coupling take place with Fmoc-amino acid chloride gave final product dipeptide ester in good to excellent yields. The protocol occurs with complete stereo chemical integrity of the configuration of substrates. Here, we revisited Schotten-Baumann condition, instead of using inorganic base. Objective: To develop green protocol for the synthesis of peptide bond using Fmoc-amino acid chloride with amino acid esters salt. Methods: The final product isolated is analyzed in several spectroscopic and analytical techniques such as FT-IR,1H-,13C-NMR, Mass spectrometry and RP-HPLC to check stereo integrity and puri-ty of the product. Conclusion: The present method developed greener using natural agro-waste (lemon fruit shell ash) derived solvent medium for the reaction and not required chemical entity.

Iterative design of a biomimetic catalyst for amino acid thioester condensation

Herein, the design of a catalyst that combines lessons learned from peptide biosynthesis, enzymes, and organocatalysts is described. The catalyst features a urea scaffold for carbonyl recognition and elements of nucleophilic catalysis. In the presence of 10 mol % of the organocatalyst, the rate of peptide bond formation is accelerated by 10000-fold over the uncatalyzed reaction between Fmoc-amino acid thioesters and amino acid methyl esters.

General, Mild, and Metal-Free Synthesis of Phenyl Selenoesters from Anhydrides and Their Use in Peptide Synthesis

A mild, practical, and simple procedure for phenyl selenoesters synthesis from several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.

An efficient mechanochemical synthesis of amides and dipeptides using 2,4,6-trichloro-1,3,5-triazine and PPh3

A rapid, facile, and efficient mechanochemical synthesis of amides from carboxylic acids has been developed through an in situ acid activation with 2,4,6-trichloro-1,3,5-triazine and a catalytic amount of PPh3. Under room temperature solvent-drop grinding of the reactants in the presence of an inorganic base, a variety of carboxylic acids including aromatic acids, aliphatic acids, and N-protected α-amino acids undergo amidation to afford amides in moderate to excellent yields. The method is also compatible with Fmoc, Cbz, and Boc protecting groups which yields protected optically active dipeptides without detectable racemization.

Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o -NosylOXY): A recyclable coupling reagent for racemization-free synthesis of peptide, amide, hydroxamate, and ester

Ubiquitousness of amide and ester functionality makes coupling reactions extremely important. Although numerous coupling reagents are available, methods of preparation of the common and efficient reagents are cumbersome. Those reagents generate a substantial amount of chemical waste and lack recyclability. Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o-NosylOXY), the first member of a new generation of coupling reagents, produces byproducts that can be easily recovered and reused for the synthesis of the same reagent, making the method more environmentally friendly and cost-effective. The synthesis of amides, hydroxamates, peptides, and esters using this reagent is described. The synthesis of the difficult sequences, for example, the islet amyloid polypeptide (22-27) fragment (with a C-terminal Gly, H-Asn-Phe-Gly-Ala-Ile-Leu-Gly-NH 2) and acyl carrier protein (65-74) fragment (H-Val-Gln-Ala-Ala-Ile- Asp-Tyr-Ile-Asn-Gly-OH), following the solid-phase peptide synthesis (SPPS) protocol and Amyloid β (39-42) peptide (Boc-Val-Val-IIe-Ala-OMe), following solution-phase strategy is demonstrated. Remarkable improvement is noticed with respect to reaction time, yield, and retention of stereochemistry. A mechanistic investigation and recyclability are also described.

Inverse peptide synthesis via activated α-aminoesters

A mild, practical, and simple procedure for peptide-bond formation is reported. Instead of activation of the carboxylic acid functionality, the reaction involves an unprecedented use of activated α-aminoesters. The method provides a straightforward entry to dipeptides and was effective when a sensitive cysteine residue was used, as no epimerization was detected in this case. The applicability of this method to iterative peptide synthesis was illustrated by the synthesis of a model tetrapeptide in the challenging reverse N→C direction. How to advance by going into reverse: In a mild and practical procedure for peptide-bond formation, free α-aminoesters were activated by treatment with N,N′-carbonyldiimidazole, instead of activating the carboxylic acid functionality (see scheme). The method provided a straightforward route to dipeptides, and its applicability to iterative peptide synthesis was illustrated by the synthesis of a tetrapeptide in the challenging reverse N→C direction.

Ethyl 2-(tert-butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as coupling reagent for racemization-free esterification, thioesterification, amidation and peptide synthesis

Here we report the synthesis and utility of ethyl 2-(tert- butoxycarbonyloxyimino)-2-cyanoacetate (Boc-Oxyma) as an efficient coupling reagent for racemization-free esterification, thioesterification, amidation reactions and peptide synthesis that uses equimolar amounts of acids and alcohols, thiols, amines or amino acids, respectively. Its application to solid phase as well as solution phase peptide synthesis is also demonstrated and a mechanistic investigation is discussed. Boc-Oxyma is similar to the well known coupling agent COMU {1-[1-cyano-2-ethoxy-2-oxoethylideneaminooxy)- dimethylaminomorpholino] uronium hexafluorophosphate} in terms of its high reactivity and mechanism of action. However, it is not only much easier to prepare, but also to recover and reuse, thereby generating far less chemical waste.

C → N and N → C solution phase peptide synthesis using the N-acyl 4-nitrobenzenesulfonamide as protection of the carboxylic function

In this paper we describe a solution phase peptide synthesis strategy using the 4-nitrobenzenesulfonamido/N-methyl-4-nitrobenzenesulfonamido group as a protecting/activating system of the carboxyl function. The 4- nitrobenzenesulfonamido group is stable during peptide chain elongation (Fmoc chemistry). The N-aminoacyl or N-dipeptidyl-4-nitrobenzensulfonamides, when activated by methylation, can be easily coupled with another amino acid or reconverted into the free-carboxyl function amino acids or peptides. This activatable protecting group allows both the C → N and the N → C direction solution phase peptide synthesis. We also verified that the absolute configuration at the chiral centers does not change during the coupling reactions. This journal is The Royal Society of Chemistry 2013.

AZIRIDINE MEDIATED NATIVE CHEMICAL LIGATION

Improved methods of native chemical ligation are provided. The methods involve reacting a thioacid (e.g. a peptide thioacid) with an aziridinyl compound (e.g. an aziridinyl peptide) under mild conditions without the use of protecting groups, and without requiring that a cysteine residue be present in the ligation product. Initial coupling of the thioacid and the aziridinyl compound yields a ligation product which contains an aziridinyl ring. Subsequent opening of the aziridinyl ring (e.g. via a nucleophilic attack) produces a linearized and modified ligation product.

Characterization of Nα-Fmoc-protected dipeptide isomers by electrospray ionization tandem mass spectrometry (ESI-MSn): Effect of protecting group on fragmentation of dipeptides

A series of positional isomeric pairs of Fmoc-protected dipeptides, Fmoc-Gly-Xxx-OY/Fmoc-Xxx-Gly-OY (Xxx = Ala, Val, Leu, Phe) and Fmoc-Ala-Xxx-OY/Fmoc-Xxx-Ala-OY (Xxx = Leu, Phe) (Fmoc = [(9-fluorenylmethyl) oxy]carbonyl) and Y = CH3/H), have been characterized and differentiated by both positive and negative ion electrospray ionization ion-trap tandem mass spectrometry (ESI-IT-MSn). In contrast to the behavior of reported unprotected dipeptide isomers which mainly produce y 1+ and/or a1+ ions, the protonated Fmoc-Xxx-Gly-OY, Fmoc-Ala-Xxx-OY and Fmoc-Xxx-Ala-OY yield significant b 1+ ions. These ions are formed, presumably with stable protonated aziridinone structures. However, the peptides with Gly- at the N-terminus do not form b1+ ions. The [M + H]+ ions of all the peptides undergo a McLafferty-type rearrangement followed by loss of CO2 to form [M + H-Fmoc + H]+. The MS3 collision-induced dissociation (CID) of these ions helps distinguish the pairs of isomeric dipeptides studied in this work. Further, negative ion MS 3 CID has also been found to be useful for differentiating these isomeric peptide acids. The MS3 of [M-H-Fmoc + H]- of isomeric peptide acids produce c1-, z1 - and y1- ions. Thus the present study of Fmoc-protected peptides provides additional information on mass spectral characterization of the dipeptides and distinguishes the positional isomers. Copyright