7451-73-2Relevant academic research and scientific papers
Visible-Light Mediated Tryptophan Modification in Oligopeptides Employing Acylsilanes
Reimler, Jannik,Studer, Armido
supporting information, p. 15392 - 15395 (2021/10/04)
A method for the selective tryptophan modification and labelling of tryptophan-containing peptides is described. Photoirradiation of acylsilanes generates reactive siloxycarbenes which undergo H?N-insertion into the indole moiety of tryptophan to give stable silyl protected hemiaminals. This method is successfully applied to chemically modify various tryptophan containing oligopeptides. The method enables the selective introduction of alkynes to peptides that are eligible for further alkyne-azide click chemistry. In addition, the dansyl fluorophore can be conjugated to a peptide using this approach.
En Route to a Heterogeneous Catalytic Direct Peptide Bond Formation by Zr-Based Metal-Organic Framework Catalysts
Conic, Dragan,De Azambuja, Francisco,Harvey, Jeremy N.,Loosen, Alexandra,Parac-Vogt, Tatjana N.,Van Den Besselaar, Maxime
, p. 7647 - 7658 (2021/06/30)
Peptide bond formation is a challenging, environmentally and economically demanding transformation. Catalysis is key to circumvent current bottlenecks. To date, many homogeneous catalysts able to provide synthetically useful methods have been developed, while heterogeneous catalysts remain largely restricted to the studies addressing the prebiotic formation of peptides. Here, the catalytic activity of Zr6-based metal-organic frameworks (Zr-MOFs) toward peptide bond formation is investigated using dipeptide cyclization as a model reaction. Unlike previous catalysts, Zr-MOFs largely tolerate water, and reactions are carried out under ambient conditions. Notably, the catalyst is recyclable and no additives to activate the COOH group are necessary, which are common limitations of previous methods. In addition, a broad reaction scope tolerates substrates with bulky and Lewis basic groups. The reaction mechanism was assessed by detailed mechanistic and computational studies and features a Lewis acid activation of carboxylate groups by Zr centers toward amine addition in which an alkoxy ligand on adjacent Zr sites assists in lowering the barrier of key proton transfers. The proposed concepts were also used to study the formation of intermolecular peptide bond formation. While intrinsic challenges associated with the catalyst structure and water removal limit a more general intermolecular reaction scope under current conditions, the results suggest that further design of Zr-MOF catalysts could render these materials broadly useful as heterogeneous catalysts for this challenging transformation.
Water-Tolerant and Atom Economical Amide Bond Formation by Metal-Substituted Polyoxometalate Catalysts
De Azambuja, Francisco,Parac-Vogt, Tatjana N.
, p. 10245 - 10252 (2019/11/03)
A simple, safe, and inexpensive amide bond formation directly from nonactivated carboxylic acids and free amines is presented in this work. Readily available Zr(IV)- and Hf(IV)-substituted polyoxometalates (POM) are shown to be catalysts for the amide bond formation reaction under mild conditions, low catalyst loading, and without the use of water scavengers, dry solvents, additives for facilitating the amine attack, or specialized experimental setups commonly employed to remove water. Detailed mechanistic investigations revealed the key role of POM scaffolds which act as inorganic ligands to protect Zr(IV) and Hf(IV) Lewis acidic metals against hydrolysis and preserve their catalytic activity in amide bond formation reactions. The catalysts are compatible with a range of functional groups and heterocycles useful for medicinal, agrochemical, and material chemists. The robustness of the Lewis acid-POM complexes is further supported by the catalyst reuse without loss of activity. This prolific combination of Zr(IV)/Hf(IV) and POMs inaugurates a powerful class of catalysts for the amide bond formation, which overcomes key limitations of previously established Zr(IV)/Hf(IV) salts and boron-based catalysts.
Oxidative couplings on tryptophan-based diketopiperazines leading to fused and bridged chemotypes
Mendive-Tapia, Lorena,Albornoz-Grados, Arantxa,Bertran, Alexandra,Albericio, Fernando,Lavilla, Rodolfo
supporting information, p. 2740 - 2743 (2017/03/10)
New chemotypes are obtained from tryptophan-containing diketopiperazines through selective C-C or C-N intramolecular oxidative couplings. The choice of the oxidant source dictates the outcome of the reaction.
AGRICULTURAL CHEMICAL CONTAINING 2,5-DIKETOPIPERAZINE DERIVATIVE AS ACTIVE INGREDIENT
-
Paragraph 0033, (2013/06/05)
Disclosed herein is an agricultural agent containing a 2,5-diketopiperazine derivative capable of controlling plant diseases and promoting plant growth or an agriculturally acceptable salt thereof as an active ingredient.
Three types of induced tryptophan optical activity compared in model dipeptides: Theory and experiment
Hudecová, Jana,Horní?ek, Jan,Budě?ínsky, Milo?,?ebestík, Jaroslav,?afa?ík, Martin,Zhang, Ge,Keiderling, Timothy A.,Bou?, Petr
, p. 2748 - 2760 (2012/10/08)
The tryptophan (Trp) aromatic residue in chiral matrices often exhibits a large optical activity and thus provides valuable structural information. However, it can also obscure spectral contributions from other peptide parts. To better understand the indu
An efficient green synthesis of proline-based cyclic dipeptides under water-mediated catalyst-free conditions
Thajudeen, Habeebullah,Park, Kyungseok,Moon, Surk-Sik,Hong, In Seok
scheme or table, p. 1303 - 1305 (2010/04/29)
l-Proline-based cyclic dipeptides were synthesized from N-Boc-protected dipeptide methyl esters under catalyst-free condition using water as a solvent. One-pot deprotection and cyclization have been used as the key steps, providing an efficient and environmentally friendly approach. Clean reaction conditions, easy isolation, and good yields of cyclic dipeptides are the salient features of the proposed methodology.
Microwave-assisted synthesis of 2,5-piperazinediones under solvent-free conditions
Lopez-Cobenas, Alberto,Cledera, Pilar,Sanchez, J. Domingo,Lopez-Alvarado, Pilar,Ramos, M. Teresa,Avendano, Carmen,Menendez, J. Carlos
, p. 3412 - 3422 (2007/10/03)
A general, efficient and environmentally friendly procedure for the synthesis of 2,5-piperazinediones is described, involving the microwave irradiation of N-Boc dipeptide esters. Georg Thieme Verlag Stuttgart.
2-PHENOXY- AND 2-PHENYLSULFOMAMIDE DERIVATIVES WITH CCR3 ANTAGONISTIC ACTIVITY FOR THE TREATMENT OF ASTHMA AND OTHER INFLAMMATORY OR IMMUNOLOGICAL DISORDERS
-
Page/Page column 44-45, (2008/06/13)
The present invention relates to a benzenesulfonamide derivative of formula (I), which is useful as an active ingredient of pharmaceutical preparations. The benzenesulfonamide derivatives of the present invention have CCR3 (CC type chemokine receptor) ant
PIPERAZINE SUBSTITUTED ARYL BENZODIAZEPINES AND THEIR USE AS DOPAMINE RECEPTOR ANTAGONISTS FOR THE TREATMENT OF PSYCHOTIC DISORDERS
-
Page/Page column 43; 45, (2010/02/07)
Described herein are antipyschotic compounds of formula (I) wherein, A is an optionally benzo-fused five or six member aromatic ring having zero to three hetero atoms independently selected from N, O, and S; Alk is (C1-4) alkylene optionally substituted w
