24469-50-9Relevant academic research and scientific papers
Synthesis of boronophenylalanine-like aza-amino acids for boron-containing azapeptide precursors
Miyata, Kota,Narita, Airi,Fujisawa, Ryota,Roppongi, Makoto,Ito, Satoshi,Shingo, Tamesue,Oba, Toru
, (2020)
Aza-amino acids and an azapeptide with a boron-containing substituent were developed for the first time. We synthesized p-boronophenylalanine (BPA)-like aza-amino acid (aza-BPA) and its analogs in which the α-carbon of the peptide is replaced by nitrogen and the boronate ester is situated at the ortho, meta, or para position of the phenyl group. The N- and C-terminals of aza-BPA were linked to α-amino acids to afford an α/aza/α-tripeptide. These compounds are expected to be used in boron neutron capture therapy, chemotherapy, and synthesis of functional materials.
Copper-catalyzed N-arylation of carbamate-protected hydrazones with organobismuthanes
Starkov, Pavel,Zemskov, Ivan,Sillard, Rannar,T?ubrik, Olga,M?eorg, Uno
, p. 1155 - 1157 (2007)
Efficient copper(II) acetate-catalyzed N-arylation of carbamate-protected hydrazones was achieved under mild reaction conditions with organobismuthanes.
Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
supporting information, (2021/04/02)
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
Synthesis of Macrocycles Derived from Substituted Triazines
Yepremyan, Akop,Mehmood, Arshad,Asgari, Parham,Janesko, Benjamin G.,Simanek, Eric E.
, p. 241 - 246 (2018/12/11)
A triazine ring derivatized with morpholine, an N-alkyl-N′-BOC-hydrazine (alkyl=isopropyl or benzyl) and the diethylacetal of glycinylpropionaldehyde undergoes spontaneous dimerization in good yields upon acid-catalyzed deprotection. The resulting 24-member macrocycles can be characterized by NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction. In the solid state, both homodimers adopt a taco-like conformation. Although each shows π–π stacking between the triazine rings, different patterns of hydrogen bonds emerge. The crystal structure of the isopropyl dimer shows that it includes two molecules of trifluoracetic acid per macrocycle. The trifluoroacetate anion charge balances the protonated triazines, which engage in bifurcated hydrogen bonds with the carbonyl acceptor of the distant glycine. This carbonyl also forms a hydrogen bond with the NH of the proximate glycine. The crystal structure of the benzyl derivative does not include trifluoracetic acid. Instead, two hydrogen bonds form, each between a glycine NH and the lone pair of the C=N nitrogen of the hydrazine group. In the solid state, both molecules present the alkyl side chains and morpholine groups in close proximity. A heterodimer is accessible in approximately statistical yields—along with both homodimers—by mixing the two protected monomers prior to subjecting them to deprotection.
Regiocontrolled and Stereoselective Syntheses of Tetrahydrophthalazine Derivatives using Radical Cyclizations
Zhang, Wei,Mo, Jia Yi,He, Weiying,Kennepohl, Pierre,Sammis, Glenn M.
supporting information, p. 976 - 980 (2019/01/04)
Tetrahydrophthalazine derivatives have found important applications in pharmaceutical research, but existing synthetic methods are unable to access them regio- and stereoselectively. Here, a new approach is presented that addresses these challenges by utilizing a 6-endo-trig radical cyclization in the key step. The desired tetrahydrophthalazines can be accessed in high yields (55–98 %) and high diastereoselectivities for the trans-product (>95:5) starting either from readily accessible hydrazones, or from the corresponding aldehydes and substituted Boc-hydrazides in a one-pot process. The synthetic versatility of the tetrahydrophthalazine core was demonstrated by its straightforward conversion to dihydro-phthalazines, phthalazines, or pyrazolo dione derivatives. Furthermore, the N?N bond was reduced to afford a new route to 1,4-diamines.
Synthesis of Highly Substituted 1,2-Diazetidin-3-ones, Small-Ring Scaffolds for Drug Discovery
Santos, Marilia S.,Nortcliffe, Andrew,Lewis, William,Bradshaw, Tracey D.,Moody, Christopher J.
supporting information, p. 8325 - 8330 (2018/06/21)
1,2-Diazetidin-3-ones are readily accessible, small ring scaffolds that upon functionalization have the potential to produce diverse 3-dimensional structures for drug discovery. Thus, treatment of diazo hydrazides, obtained from simple hydrazides and malonyl half ester derivatives, followed by diazo transfer, with catalytic amounts of rhodium(II) acetate dimer results in intramolecular carbenoid N?H insertion to give 1,2-diazetidin-3-ones. Although subsequent functionalization reactions could be hampered by the lability of the 4-membered ring, a wide range of new derivatives was available by deprotection at N-1, and subsequent amide or urea formation. The structures of four four-membered rings was confirmed by X-ray crystallography; the compounds showed modest growth inhibitory activity in mammary carcinoma cells.
Towards a general synthesis of di-aza-amino acids containing peptides
Bizet, Faustine,Tonali, Nicolo,Soulier, Jean-Louis,Oliva, Agostino,Kaffy, Julia,Crousse, Benoit,Ongeri, Sandrine
, p. 17062 - 17072 (2018/10/23)
While the incorporation of one aza-amino acid in peptides has been proved to be beneficial for inducing a structure constraint, increasing the resistance towards proteolysis and improving the biological activity, only very rare examples of the incorporation of two or more consecutive aza-amino acids have been reported. In this work, we demonstrate that this fact is probably due to the unsuspected difficulty in synthesizing such peptide analogues, as illustrated by the synthesis of tripeptide derivatives containing two consecutive aza-amino acids. Herein, we report some general guidelines regarding the activation and the coupling of alkyl-hydrazides either mutually or with a natural amino acid, taking into account their nucleophilicity and the nature of their side chains.
Exploration of a Au(i)-mediated three-component reaction for the synthesis of DNA-tagged highly substituted spiroheterocycles
Klika ?kopi?, Mateja,Willems, Suzanne,Wagner, Bernd,Schieven, Justin,Krause, Norbert,Brunschweiger, Andreas
supporting information, p. 8648 - 8654 (2017/10/27)
We demonstrate a Au(i)-mediated three-component reaction to DNA-tagged highly substituted 6-oxa-1,2-diazaspiro[4.4]nonanes from either DNA-coupled aldehydes, hydrazides, or alkynols. The choice of the starting material coupled to the DNA tag was critial for the purity of the product as the DNA-aldehyde conjugate yielded the purest products, whereas the alkynol- and hydrazide conjugates returned complex product mixtures. The reaction was compatible with thymine-, cytosine-, and, surprisingly, with adenine-DNA, while guanine-containing DNA strands were degraded under the reaction conditions.
The continuous-flow synthesis of carbazate hydrazones using a simplified computer-vision controlled liquid–liquid extraction system
O'Brien, Matthew,Cooper, Dennis A.,Mhembere, Panashe
supporting information, p. 5188 - 5191 (2016/11/13)
A computer-vision controlled liquid–liquid extraction system was used in the continuous-flow synthesis of a series of carbazate hydrazones. The system uses open-source software components (Python, OpenCV) and is simpler and potentially more economical, in terms of hardware, than one we have described previously.
Gold-catalyzed three-component spirocyclization: A one-pot approach to functionalized pyrazolidines
Wagner, Bernd,Hiller, Wolf,Ohno, Hiroaki,Krause, Norbert
supporting information, p. 1579 - 1583 (2016/02/10)
An efficient, highly atom economic synthesis of hitherto unknown spirocyclic pyrazolidines in a one-pot process was developed. The gold-catalyzed three-component coupling of alkynols, hydrazines and aldehydes or ketones likely proceeds via cycloisomerization of the alkynol to an exocyclic enol ether and subsequent [3 + 2]-cycloaddition of an azomethine ylide. A library of 29 derivatives with a wide range of functional groups was synthesized in up to 97% yield. With this new method, every position in the final product can be substituted which renders the method ideal for applications in combinatorial or medicinal chemistry.
