16714-25-3Relevant academic research and scientific papers
Evidence of a Nitrene Tunneling Reaction: Spontaneous Rearrangement of 2-Formyl Phenylnitrene to an Imino Ketene in Low-Temperature Matrixes
Nunes, Cláudio M.,Knezz, Stephanie N.,Reva, Igor,Fausto, Rui,McMahon, Robert J.
, p. 15287 - 15290 (2016)
Triplet 2-formyl phenylnitrene was generated by photolysis of 2-formyl phenylazide isolated in Ar, Kr, and Xe matrixes and characterized by IR, UV-vis, and EPR spectroscopies. Upon generation at 10 K, the triplet nitrene spontaneously rearranges in the dark to singlet 6-imino-2,4-cyclohexadien-1-ketene on the time scale of several hours. The intramolecular [1,4] H atom shift from the nitrene to the imino ketene occurs by tunneling, on the triplet manifold, followed by intersystem crossing. This case constitutes the first direct evidence of a tunneling reaction involving a nitrene.
Synthesis of 3-Aryl-2-nitroindoles by Palladium-Catalyzed CH-Activation Reactions
Ivanov, Anton,Iaroshenko, Viktor O.,Villinger, Alexander,Langer, Peter
, p. 2285 - 2287 (2015)
3-Aryl-2-nitroindoles were prepared via CH-activation reactions of N-methyl-2-nitroindole.
A simple synthesis of 2-{2-[(arylmethylidene)amino]-indazol-3-yl}malonate esters
Kuznetsova, Lyubov I.,Chagarovskiy, Alexey O.,Levina, Irina I.,Rybakov, Victor B.,Ivanova, Olga A.,Trushkov, Igor V.
, p. 555 - 561 (2020)
[Figure not available: see fulltext.] A method was developed for the synthesis of dimethyl {2-[(arylmethylidene)amino]-2H-indazol-3-yl}malonates on the basis of a Knoevenagel condensation between 2-azidobenzaldehyde and dimethyl malonate, followed by treatment of the obtained adduct with aromatic aldehydes in the presence of polymer-supported triphenylphosphine. It was shown that the interaction of the synthesized Schiff bases with Corey ylide provided a route for the synthesis of 2-(aziridin-1-yl)indazoles.
Indolidenes and Indolidenium Intermediates in the Synthesis of Cyclopent[b]indoles: Mechanistic Studies on Intramolecular Cyclizations
Feldman, Ken S.,Gonzalez, Inanllely Y.,Glinkerman, Christopher M.
, p. 11849 - 11862 (2015)
Tetracyclic products featuring predominantly a trans-hexahydroindane unit annelated onto the C(2)/C(3) positions of indole can be accessed by intramolecular cyclocondensation of tethered alkenyl sulfides with either indolidene or indolidenium cation intermediates. Studies with geometrically pure E- and Z-alkenyl sulfide isomers reveal a likely dichotomy of reaction paths that provide mixtures of both regioisomers and stereoisomers of the hexahydroindane adducts.
Novel substituted triazolo benzodiazepine scaffolds to explore chemical space
Abeykoon, Gayan A.,Sahn, James J.,Martin, Stephen F.
, (2021/02/16)
Efficient and concise routes to sets of novel triazolo-1,4-benzodiazepine scaffolds that are suitably functionalized for diversification at three positions to explore three-dimensional space with different substituents are described. One approach to these scaffolds features a simplified multicomponent assembly process to give an intermediate azido alkyne that undergoes a facile Huisgen dipolar cycloaddition. The triazolo-1,4-benzodiazepines thus produced may be endowed with aryl halide, secondary amino, alcohol, aldehyde or carboxylic acid groups as functional handles for orthogonal derivatization reactions. Modification of this approach enabled the facile synthesis of the related triazolo-1,4-benzodiazepin-6-ones, also bearing three functional handles. These convenient protocols were used to prepare multi-gram quantities of benzodiazepine analogs as precursors for generating compound libraries for screening campaigns.
Iron-Catalyzed Radical Activation Mechanism for Denitrogenative Rearrangement Over C(sp3)–H Amination
Roy, Satyajit,Das, Sandip Kumar,Khatua, Hillol,Das, Subrata,Singh, Krishna Nand,Chattopadhyay, Buddhadeb
supporting information, p. 8772 - 8780 (2021/03/16)
An iron-catalyzed denitrogenative rearrangement of 1,2,3,4-tetrazole is developed over the competitive C(sp3)–H amination. This catalytic rearrangement reaction follows an unprecedented metalloradical activation mechanism. Employing the developed method, a wide number of complex-N-heterocyclic product classes have been accessed. The synthetic utility of this radical activation method is showcased with the short synthesis of a bioactive molecule. Collectively, this discovery underlines the progress of radical activation strategy that should find wide application in the perspective of medicinal chemistry, drug discovery and natural product synthesis research.
Effective microwave-assisted approach to 1,2,3-triazolobenzo-diazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition
Mazur, Maryna O.,Zhelavskyi, Oleksii S.,Zviagin, Eugene M.,Shishkina, Svitlana V.,Musatov, Vladimir I.,Kolosov, Maksim A.,Shvets, Elena H.,Andryushchenko, Anna Yu,Chebanov, Valentyn A.
supporting information, p. 678 - 687 (2021/04/09)
A novel catalyst-free synthetic approach to 1,2,3-triazolobenzodiazepinones has been developed and optimized. The Ugi reaction of 2-azidobenzaldehyde, various amines, isocyanides, and acids followed by microwave-assisted intramolecular azide–alkyne cycloaddition (IAAC) gave a series of target heterocyclic compounds in moderate to excellent yields. Surprisingly, the normally required ruthenium-based catalysts were found to not affect the IAAC, only making isolation of the target compounds harder while the microwave-assisted catalyst-free conditions were effective for both terminal and non-terminal alkynes.
Regio- and Stereoselective Cascade of β,γ-Unsaturated Ketones by Dipeptided Phosphonium Salt Catalysis: Stereospecific Construction of Dihydrofuro-Fused [2,3-b] Skeletons
Chen, Yayun,He, Jiajia,Jiang, Chunhui,Ren, Xiaoyu,Su, Zhishan,Wang, Tianli,Xiao, Kai,Zhang, Hongkui,Zhuang, Cheng
supporting information, p. 19860 - 19870 (2021/08/06)
Chiral (dihydro)furo-fused heterocycles are significant structural motifs in numerous natural products, functional materials and pharmaceuticals. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we develop an effective, modular method by a dipeptide-phosphonium salt-catalyzed regio- and stereoselective cascade reaction of readily available linear β,γ-unsaturated ketones with aromatic alkenes, affording a wide variety of structurally fused heterocyclic molecules in high yields with excellent stereoselectivities. Moreover, mechanistic investigations revealed that the bifunctional phosphonium salt controlled the regio- and stereoselectivities of this cascade reaction, particularly proceeding through the initial ketone α-addition followed by O-participated substitution; and the multiple hydrogen-bonding interactions between Br?nsted acid moieties of catalyst and nitro group of aromatic alkene were crucial in asymmetric induction. Given the generality, versatility, and high efficiency of this method, we anticipate that it will have broad synthetic utilities.
One-pot, two-step synthesis of 3,4-dihydroquinazoline-2(1H)-thiones from o-azidobenzenealdehydes, aryl amines and carbon disulfide
Zhang, Wensheng,Li, Yan,Zhou, Hongyan,Su, Xiaoli,Zhang, Xiaofeng,Zhang, Wei
supporting information, (2021/09/02)
A one-pot, two-step method was developed for the synthesis of 3-aryl-3,4-dihydroquinazoline-2(1H)-thiones involving the reductive amination of o-azidobenzaldehydes and aryl amines followed by the Staudinger-aza-Wittig reaction with CS2.
1H-1,2,3-triazole embedded Isatin-Benzaldehyde-bis(heteronuclearhydrazones): design, synthesis, antimycobacterial, and cytotoxic evaluation
Johansen, Matt D.,Kremer, Laurent,Kumar, Sumit,Kumar, Vipan,Preeti,Sharma, Bharvi
, (2021/12/09)
Rapid growth of global drug-resistant tuberculosis and urgent requirement for short treatment regimens is stimulating the need for discovery of new TB drugs. In this work, we report the design, synthesis and in vitro antimycobacterial evaluation of a library of isatin-derived bis(heteronuclear hydrazones). Evaluation results revealed that the inclusion of isoniazid core into 1H-1,2,3-triazole tethered isatin-benzaldehydes improved the antimycobacterial activity on tuberculosis mc26230 strain and significantly reduced the cytotoxicity against Vero cells. However, the introduction of semicarbazones/thiosemicarbazones or pyrazine-2-carbohydrazide produced the opposite effects. The compounds with isoniazid and polar-donating groups at the C-5 position of isatin emerged as the most promising conjugates with MIC99?=?0.36?μg/ml. The most active compounds were non-cytotoxic to Vero cells (IC50>100?μg/ml) with selectivity indices >277.
