532-96-7Relevant academic research and scientific papers
Synthesis of 3 H-1,2,4-Triazol-3-ones via NiCl2-Promoted Cascade Annulation of Hydrazonoyl Chlorides and Sodium Cyanate
Du, Shiying,Yang, Zuguang,Tang, Jianhua,Chen, Zhengkai,Wu, Xiao-Feng
supporting information, p. 2359 - 2363 (2021/04/05)
A nickel-promoted cascade annulation reaction for the facile synthesis of 3H-1,2,4-triazol-3-ones from readily available hydrazonoyl chlorides and sodium cyanate has been developed. The transformation occurs through a cascade nickel-promoted intermolecular nucleophilic addition-elimination process, intramolecular nucleophilic addition, and a hydrogen-transfer sequence. The method has been successfully applied for the construction of the core skeleton of the angiotensin II antagonist.
Regioselective Decarboxylative Cycloaddition Route to Fully Substituted 3-CF3-Pyrazoles from Nitrilimines and Isoxazolidinediones
Tian, Yu-Chen,Li, Jun-Kuan,Zhang, Fa-Guang,Ma, Jun-An
supporting information, p. 2093 - 2097 (2021/03/15)
1,4-Diaryl-5-carboxamido substituted 3-trifluoromethylpyrazoles are obtained with exclusive regioselectivity under transition-metal-free conditions. This decarboxylative [3+2] cycloaddition protocol was enabled by employing trifluoromethyl nitrilimines as 1,3-dipoles, and isoxazolidinediones as CO2-masked alkynyl dipolarophiles. The applicability of this method is further manifested by its compatibility with difluoromethyl, alkyl, aryl, and heteroaryl nitrilimines, as well as the preparation of 4-carboxylic amido analogue of drug Celebrex. (Figure presented.).
Hydrogen peroxide based oxidation of hydrazines using HBr catalyst
Du, Wanting,Ma, Zichao,Shao, Liming,Wang, Jian
, (2021/11/18)
Azo compounds (RN = NR′) are an important class of organic molecules that find wide application in organic synthesis. Herein, we report an efficient, practical and metal-free oxidation of hydrazines (RNH-NHR’) to azo compounds using 5 mol% HBr and hydrogen peroxide as terminal oxidant. This new method has been demonstrated by 40 examples with excellent yields. In addition, we showcased two examples of the one-pot sequential reactions involving our hydrazine oxidation/hydrolysis/Heck reaction or Cu-catalyzed N-arylation with aryl boronic acid. The distinct advantages of this protocol include metal-free catalysis, waste prevention, and easy operation.
From Phenylhydrazone to 1H-1,2,4-Triazoles via Nitrification, Reduction and Cyclization
Hao, Liqiang,Wang, Guodong,Sun, Jian,Xu, Jun,Li, Hongshuang,Duan, Guiyun,Xia, Chengcai,Zhang, Pengfei
supporting information, p. 1657 - 1662 (2020/03/19)
Herein we report an annulation of phenylhydrazone via a tandem nitrification, reduction, cyclization protocol employing cobalt nitrate and 1,2-dichloroethane to produce substituted 1H-1,2,4-triazoles. Notably, 1,2-dichloroethane serves both the solvent and a hydrogen source for transfer hydrogenation. This methodology works under mild conditions, providing a direct approach for the synthesis of 1H-1,2,4-triazoles. (Figure presented.).
Copper-Catalyzed Tandem Dehydrocyanation and [3+2] Cyclo-addition Reactions of Phenacylmalononitriles: Regioselective Synthesis of Functionalized 4-Benzoyl-5-cyanopyrazoles under Mild Conditions
Khaledian, Omid,Yavari, Issa
, p. 1379 - 1386 (2020/04/27)
A novel copper-catalyzed [3+2] cycloaddition reaction with concomitant in situ generation of benzoylacrylonitriles and nitrile imines from phenacylmalononitriles and hydrazonoyl chlorides, respectively, is reported. The reaction was performed using copper(I) chloride as catalyst and N-methylimidazole as a clean complexing agent/weak base to afford the functionalized 4-benzoyl-5-cyanopyrazoles in moderate to good yields and excellent regioselectivity under ambient conditions. This method provides rapid access to a wide range of highly functionalized 4-benzoyl-5-cyanopyrazoles.
A formal [3+2] cycloaddition reaction of: N -methylimidazole as a masked hydrogen cyanide: Access to 1,3-disubstitued-1 H -1,2,4-triazoles
Yavari, Issa,Khaledian, Omid
supporting information, p. 9150 - 9153 (2020/10/02)
N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C-N bond cleavages. This journal is
Diversity Oriented Clicking (DOC): Divergent Synthesis of SuFExable Pharmacophores from 2-Substituted-Alkynyl-1-Sulfonyl Fluoride (SASF) Hubs
Barrow, Andrew S.,Cheng, Yunfei,Gialelis, Timothy L.,Giel, Marie-Claire,Kitamura, Seiya,Li, Gencheng,Moses, John E.,Ottonello, Alessandra,Sharpless, K. Barry,Smedley, Christopher J.,Wolan, Dennis W.
supporting information, p. 12460 - 12469 (2020/06/10)
Diversity Oriented Clicking (DOC) is a unified click-approach for the modular synthesis of lead-like structures through application of the wide family of click transformations. DOC evolved from the concept of achieving “diversity with ease”, by combining classic C?C π-bond click chemistry with recent developments in connective SuFEx-technologies. We showcase 2-Substituted-Alkynyl-1-Sulfonyl Fluorides (SASFs) as a new class of connective hub in concert with a diverse selection of click-cycloaddition processes. Through the selective DOC of SASFs with a range of dipoles and cyclic dienes, we report a diverse click-library of 173 unique functional molecules in minimal synthetic steps. The SuFExable library comprises 10 discrete heterocyclic core structures derived from 1,3- and 1,5-dipoles; while reaction with cyclic dienes yields several three-dimensional bicyclic Diels–Alder adducts. Growing the library to 278 discrete compounds through late-stage modification was made possible through SuFEx click derivatization of the pendant sulfonyl fluoride group in 96 well-plates—demonstrating the versatility of the DOC approach for the rapid synthesis of diverse functional structures. Screening for function against MRSA (USA300) revealed several lead hits with improved activity over methicillin.
Controlled polymerization of styrene in the presence of Blatter’s radicals
Burdyukova, T. O.,Fedorov, A. Yu.,Grishin, I. D.,Kuznetsova, Yu. L.,Lopatin, M. A.,Malysheva, Yu. B.,Polozov, E. Yu.,Vavilova, A. S.,Zaburdaeva, E. A.
, p. 1470 - 1477 (2020/09/23)
Controlled polymerization of styrene (both self-initiated and initiated with azobisisobutyronitrile) in the presence of Blatter’s radical at 125 °C was studied. When using the radical initiator, there is no induction period. On the basis of UV spectroscopy and MALDI massspectrometry studies, it was established that the Blatter radical is completely consumed at the initial stage of the polymerization, inserting into almost all macromolecules. The prepared polystyrene exhibits the ability to reinitialization in post-polymerization and the synthesis of block copolymers.
Thermally and Magnetically Robust Triplet Ground State Diradical
Gallagher, Nolan,Zhang, Hui,Junghoefer, Tobias,Giangrisostomi, Erika,Ovsyannikov, Ruslan,Pink, Maren,Rajca, Suchada,Casu, Maria Benedetta,Rajca, Andrzej
supporting information, (2019/03/26)
High spin (S = 1) organic diradicals may offer enhanced properties with respect to several emerging technologies, but typically exhibit low singlet triplet energy gaps and possess limited thermal stability. We report triplet ground state diradical 2 with a large singlet-triplet energy gap, ?"EST ≥ 1.7 kcal mol-1, leading to nearly exclusive population of triplet ground state at room temperature, and good thermal stability with onset of decomposition at a160 °C under inert atmosphere. Magnetic properties of 2 and the previously prepared diradical 1 are characterized by SQUID magnetometry of polycrystalline powders, in polystyrene glass, and in other matrices. Polycrystalline diradical 2 forms a novel one-dimensional (1D) spin-1 (S = 1) chain of organic radicals with intrachain antiferromagnetic coupling of J′/k = a14 K, which is associated with the N···N and N···O intermolecular contacts. The intrachain antiferromagnetic coupling in 2 is by far strongest among all studied 1D S = 1 chains of organic radicals, which also makes 1D S = 1 chains of 2 most isotropic, and therefore an excellent system for studies of low-dimensional magnetism. In polystyrene glass and in frozen benzene or dibutyl phthalate solution, both 1 and 2 are monomeric. Diradical 2 is thermally robust and is evaporated under ultrahigh vacuum to form thin films of intact diradicals on silicon substrate, as demonstrated by X-ray photoelectron spectroscopy. Based on C-K NEXAFS spectra and AFM images of the a1.5 nm thick films, the diradical molecules form islands on the substrate with molecules stacked approximately along the crystallographic a-axis. The films are stable under ultrahigh vacuum for at least 60 h but show signs of decomposition when exposed to ambient conditions for 7 h.
Intramolecular Diels-Alder and [3+2] Cycloaddition Reactions in the One-Pot Synthesis of Epoxypyrrolo[3,4-g]indazoles
Alizadeh, Abdolali,Amir Ashjaee Asalemi, Kaveh,Halvagar, Mohammadreza
supporting information, p. 2936 - 2944 (2019/07/22)
A one-pot approach for the synthesis of epoxypyrrolo[3,4- g ]indazoles is presented. The first step was initiated by a three-component reaction of an isocyanide, a dialkyl acetylenedicarboxylate, and 2-furancarboxylic acid, and led to 1,3-dioxoepoxyisoindole, followed by the addition of hydrazonoyl chloride through a [3+2]-cycloaddition reaction in the second step. The key step in the formation of final compound involves a bicyclization strategy through intramolecular Diels-Alder (IMDA) reaction.
