28635-78-1

Upstream product

• 122237-16-5 DC-FM-bar-Phe-Leu-O-t-Bu 
• 29842-94-2 (S)-tert-butyl 2-((S)-2-(((benzyloxy)carbonyl)amino)-3-phenylpropanamido)-4-methylpentanoate 
• 134982-29-9 TCBOC-Phe-Leu-OtBu 
• 84891-01-0 Fmoc-Phe-Leu-OtBu 
• 116864-70-1 Noc-Phe-Leu-OtBu 
• 3303-55-7 L-Phe-Leu 
• 115-11-7 isobutene 
• 1161-13-3 N-Cbz-L-Phe 
• 21691-53-2 L-leucine tert-butyl ester 
• 35661-40-6 N-Fmoc L-Phe 
• 2748-02-9 L-leucine tert-butyl ester hydrochloride 
• 63-91-2 L-phenylalanine 
• 100167-06-4 TCBOC-Phe-OH 
• 122236-89-9 DC-FM-bar-Phe-OH 

Downstream Products

• 77426-95-0 Z-Gly-Gly-Phe-Leu-O-t-butyl 
• 138850-03-0 Cbz-Leu-Leu-Phe-Leu-OtBu 
• 138850-04-1 Cbz-Val-Leu-Phe-Leu-OtBu 
• 58822-25-6 Leu-enkephalin 
• 116264-39-2 (S)-2-{(S)-2-[2-(4-Methoxy-benzylsulfanyl)-ethylamino]-3-phenyl-propionylamino}-4-methyl-pentanoic acid tert-butyl ester 
• 123167-99-7 (S)-2-{(S)-2-[2-(2,7-Di-tert-butyl-10,10-dioxo-9,10-dihydro-10λ⁶-thioxanthen-9-ylmethoxycarbonylamino)-acetylamino]-3-phenyl-propionylamino}-4-methyl-pentanoic acid tert-butyl ester 
• 82362-18-3 Z-Gly-Phe-Leu-OBu^t 
• 81678-16-2 leucine enkephalin acetate 
• 77426-98-3 Gly-Gly-Phe-Leu-OBu^t 
• 427881-22-9 (S)-2-[(S)-2-(2-{2-[(S)-2-Amino-3-(4-tert-butoxy-phenyl)-propionylamino]-acetylamino}-acetylamino)-3-phenyl-propionylamino]-4-methyl-pentanoic acid tert-butyl ester 
• 89137-25-7 (S)-2-((S)-2-{2-[2-(9H-Fluoren-9-ylmethoxycarbonylamino)-acetylamino]-acetylamino}-3-phenyl-propionylamino)-4-methyl-pentanoic acid tert-butyl ester 
• 138372-38-0 Fmoc-Tyr(OBu^t)-Gly-Gly-Phe-Leu-OBu^t 
• 149204-99-9 Fmoc-Gly-L-Phe-L-Leu-OtBu 
• 122269-93-6 DC-FM-bar-Tyr(t-Bu)-Gly-Gly-Phe-Leu-O-t-Bu 

Relevant academic research and scientific papers

Peptide Bond Formation of Amino Acids by Transient Masking with Silylating Reagents

A one-pot peptide bond-forming reaction has been developed using unprotected amino acids and peptides. Two different silylating reagents, HSi[OCH(CF3)2]3 and MTBSTFA, are instrumental for the successful implementation of this approach, being used for the activation and transient masking of unprotected amino acids and peptides at C-termini and N-termini, respectively. Furthermore, CsF and imidazole are used as catalysts, activating HSi[OCH(CF3)2]3 and also accelerating chemoselective silylation. This method is versatile as it tolerates side chains that bear a range of functional groups, while providing up to >99% yields of corresponding peptides without any racemization or polymerization.

Naphthoquinones as covalent reversible inhibitors of cysteine proteases—studies on inhibition mechanism and kinetics

The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4‐naphthoquinones with a dipeptidic recognition motif (HN‐L‐Phe‐L‐Leu‐OR) in the 2‐position and an electron‐withdrawing group (EWG) in the 3‐positio

Stereocontrolled [11C]Alkylation of N-Terminal Glycine Schiff Bases To Obtain Dipeptides

The use of various quaternary ammonium salts as chiral phase-transfer catalysts allowed effective and stereoselective radiochemical [11C]alkylation to obtain functionalized dipeptides. We herein report a broadly applicable procedure for the asymmetric [11C]alkylation of dipeptides to give labeled N-terminal peptides by using different [11C]alkyl halides. Contended stereoselectivities of the reactions were observed by using 11C-labeled alkyl halides, [11C]methyl iodide and [11C]benzyl iodide, and diastereomeric ratios with different specialized catalysts of 95:5 and 90:10 were achieved, respectively. Accordingly, the straightforward synthesis of enantioenriched compounds should play a vital role in peptide-based radiopharmaceutical development and positron emission tomography imaging.

Ynamides as Racemization-Free Coupling Reagents for Amide and Peptide Synthesis

A highly efficient, two-step, one-pot synthetic strategy for amides and peptides was developed by employing ynamides as novel coupling reagents under extremely mild reaction conditions. The ynamides not only are effective for simple amide and dipeptide synthesis but can also be used for peptide segment condensation. Importantly, no racemization was detected during the activation of chiral carboxylic acids. Excellent amidation selectivity toward amino groups in the presence of -OH, -SH, -CONH2, ArNH2, and the NH of indole was observed, making the protection of these functional groups unnecessary in amide and peptide synthesis.

Synthesis of IB-01212 by multiple N-methylations of peptide bonds

There are many natural peptides with multiple N-methylamino acids that exhibit potent attractive biological activities. N-methylation of a peptide bond(s) is also one of the standard approaches in medicinal chemistry of bioactive peptides, to improve the

The 2-(triphenylsilyl)ethoxycarbonyl-("Tpseoc"-) group: A new silicon-based, fluoride cleavable oxycarbonyl protecting group highly orthogonal to the Boc-, Fmoc- and Cbz-groups

Starting from 2-(triphenylsilyl)ethanol a new oxycarbonyl protecting group cleavable by fluoride ion induced Peterson-elimination has been developed. Known 2-(triphenylsilyl)ethanol has been prepared from commercially available triphenylvinylsilane by a hydroboration-oxidation sequence using the sterically hindered borane reagent 9-BBN. The silyl alcohol was subsequently transformed into its chloroformate, imidazolylcarboxylic acid ester and p-nitrophenyl carbonate and used in standard protocols for the formation of carbamates and carbonates. The Tpseoc group proved to be highly resistant against acidic conditions applied in removal of tert-butyl esters and the t-Boc-group. It also withstood catalytic hydrogenation, treatment with morpholine, methylhydrazine and Pd-reagents/allyl-scavanger combinations, conditions required to cleave Cbz-, Fmoc-, phthalimide- and Alloc-groups. The Tpseoc-group is cleaved upon treatment with TBAF/CsF at 0 °C or r.t. with cleavage times reaching from 10 min. to 24 h. Its orthogonality, ease of cleavage and UV-detectability makes the Tpseoc-group a promising alternative to other widely used silicon based amine protecting groups like the Teoc- and SES-groups.

Highly stereoselective peptide modifications through Pd-catalyzed allylic alkylations of chelated peptide enolates

Deprotonation of peptides in the presence of zinc chloride gives rise to highly reactive nucleophiles that can be subjected to palladium-catalyzed allylic alkylation reactions. Excellent diastereoselectivities are obtained that are nearly independent of the allylic substrate used. By using this protocol, highly functionalized side chains can also be incorporated in excellent yields and selectivities. The stereochemicaloutcome of the reaction is exclusively controlled by the peptide chain as long as terminal π-allyl-palladium complexes are involved. Probably, there is a threefold coordination, at least, ofthe deprotonated peptide chain to the chelating zinc ion. In such metal peptide complexes, one face of the generated enolate is shielded by the side chain of the adjacent amino acid, thus directing the electrophilic attack onto the opposite face. This behavior explains why an S amino acid always generates an R amino acid (and the other way round).

Magnesium/hydrazinium monoformate: A new hydrogenation method for removal of some commonly used protecting groups in peptide synthesis

Removal of some commonly used protecting groups in peptide synthesis by catalytic transfer hydrogenation employing hydrazinium monoformate and magnesium is described. This method is equally competitive with other methods in deblocking most of the commonly used protecting groups in peptide synthesis. tert-Butyl derived and base labile protecting groups were completely stable under these conditions. The use of Mg/NH2-NH2·HCOOH makes this a rapid, low-cost alternative to palladium and reduces the work-up to a simple and extraction operation.

Total Masking -Gly Bonds by Highly Lipophilic and Chromophoric Ferrocenylmethyl Residue in Peptide Syntheses of Hexaglycine and Leu-Enkephalin

Highly lipophilic and chromophoric ferrocenylmethyl residue is applied to syntheses of peptides hexaglycine and Leu-enkephalin, masking therein all -Gly bonds.Thereby Fem groups influence properties of Fem-peptide derivatives advantageously both in chemosyntheses and cleaning operations, leading to constantly high yields et each step.Despite of its volumous dimension the Fem residue can be introduced into each peptide bond of oligoglycine by succeeding one another of building blocks of H-Fem-Gly-OMe.Strong alkaline conditions during the hydrolyses of methyl esters occurring several times in peptide derivatives do not influence the Gly-Gly-bond at all.Total protected derivatives BOC-(Fem-Gly-)6-OMe and BOC-Tyr(t-Bu)-(Fem-Gly-)2Phe-Leu-OtBu even are soluble in hexane/ethylacetate (1:1).

The catalytic formation of peptide bonds with carbohydrate protein conjugates of proteases [CPC (proteases)]

This paper describes the use of carbohydrate protein conjugates of proteases [CPC(proteases)] for the catalytic formation of peptide bonds. We have found that CPC(proteases) are stable in organic solvents and perform at truly catalytic levels and have dem