61946-90-5Relevant academic research and scientific papers
Design and synthesis of sinomenine isoxazole derivatives via 1,3-dipolar cycloaddition reaction
Pan, Hongmei,Lu, Tong,Wu, Xuedan,Gu, Chengwen,Tao, Naili,Zhang, Biao,Wang, Ao,Chen, Guangmei,Zhang, Kehua,Cheng, Jie,Jin, Jie
supporting information, p. 2360 - 2364 (2019/11/11)
A novel structure of sinomenine isoxazole derivatives is synthesised from sinomenine hydrochloride and aromatic aldehydes and requires six steps. 19 target compounds have been obtained in good yields. The sinomenine hydrochloride transforms to 4-alkynyl sinomenine, which is a key intermediate product to synthesise the target sinomenine isoxazole compounds, after a neutralisation reaction with ammonia and substitution reaction with 3-chloropropyne. Another key intermediate product is 1,3-dipole, which can be obtained from aromatic aldehyde. After treatment with hydroxylamine hydrochloride and then sodium carbonate solution, aromatic aldehyde is converted to aldehyde oxime, which reacts with N-chlorosuccinimide (NCS) to afford aryl hydroximino chloride. 1,3-Dipole is eventually formed in situ while triethylamine (TEA) in DMF is added dropwise. Then 4-alkynyl sinomenine is added to provide the sinomenine isoxazole derivative via 1,3-dipolar cycloaddition reaction as the key step. All the target compounds are characterised by melting point, 1H NMR, 13C NMR, HRMS and FT-IR spectroscopy.
Copper-catalysed synthesis of 3,5-disubstituted isoxazoles enabled by pyridinyl benzimidazol (PBI) as a bidentate N-chelating ligand under mild conditions
Khalifeh, Reza,Shahriarpour, Fatemeh,Sharghi, Hashem,Aberi, Mahdi
, p. 813 - 821 (2018/03/01)
In this paper, we introduced pyridinyl benzimidazol (PBI) as an easy-to-handle and bidentate N-chelating ligand that promote clean synthesis of 3,5-disubstituted isoxazoles in the presence of copper acetate as catalyst. This catalytic approach initiates with the hydroxyamination of aldehydes followed by chlorination and then generation of nitrile oxide which subsequently undergoes click-type [3?+?2]-dipolar cycloaddition with alkynes to give isoxazoles. This method provides an alternative green process to construct isoxazole derivatives.
Easy Access to 1-Amino and 1-Carbon Substituted Isoquinolines via Cobalt-Catalyzed C - H/N - O Bond Activation
Muralirajan, Krishnamoorthy,Kuppusamy, Ramajayam,Prakash, Sekar,Cheng, Chien-Hong
supporting information, p. 774 - 783 (2016/03/09)
A green atom-economical method for the synthesis of highly functionalized 1-amino and 1-carbon substituted isoquinolines from the reaction of N′-hydroxybenzimidamides and aryl ketoximes, respectively, with alkynes via pentamethylcyclopentadienylcobalt(III)-catalyzed C - H/N - O bond activation is described. The external oxidant-free annulation reaction uses the =NOH moiety in N′-hydroxybenzimidamides or N-aromatic ketone oximes as the directing group and internal oxidant. This first row transition metal-catalyzed annulation serves as an efficient alternative for the synthesis of isoquinolines, as water is the only by-product and expensive noble metals such as rhodium(III), iridium(III), palladium(II), and ruthenium(II) are not required. The reaction proceeds via C - H activation, alkyne insertion, reductive elimination, and N - O activation.
Side-chain prototropic tautomerism of 4-hydroxyfuroxans in methylation reactions
Fershtat, Leonid L.,Epishina, Margarita A.,Ovchinnikov, Igor V.,Struchkova, Marina I.,Romanova, Anna A.,Ananyev, Ivan V.,Makhova, Nina N.
supporting information, p. 5685 - 5689 (2016/11/28)
A general and simple method for the preparation of under explored 3-aryl-4-hydroxyfuroxans by nucleophilic substitution of the nitro group in 3-aryl-4-nitrofuroxans using NaOH in H2O-THF has been developed. The methylation of 3-aryl-4-hydroxyfu
1,3-dipolar cycloaddition reaction of nitrile oxides revisited - Unusual side products characterized by 2d NMR
Gucma,Golebiewski
, p. 572 - 578 (2014/06/10)
Cycloaddition of (4-trifluoromethyl)phenylnitrile oxide to N-(4-methoxyphenyl)acrylamide afforded bicyclic tetrahydro-oxazolo-(3,2-b)[1,3] oxazine-2-carboxamide derivative in result of N-acylation of the initially formed cycloadduct by the dipolarophile.
Synthesis and biological activity of 3-substituted isoxazolecarboxamides
Gucma, Miroslaw,Golebiewski, W. Marek
scheme or table, p. 461 - 469 (2011/07/30)
A series of novel 3-substituted isoxazolecarboxamides have been prepared. A key step was 1,3-dipolar cycloaddition of nitrile oxides to α,β-unsaturated esters. Some of these compounds exhibited high fungicidal activities against Alternaria alternata, Botrytis cinerea, Rhizoctonia solani, Fusarium culmorum, and Phytophthora cactorum.
Enantioselective 1,3-dipolar cycloaddition reactions using chiral lanthanide catalysts
Golebiewski, W. Marek,Gucma, Miroslaw
experimental part, p. 1687 - 1693 (2009/09/06)
(Chemical Equation Presented) Regio- and stereoselective 1,3-dipolar cycloaddition of nitrile oxides to internal 2-pentenols, α,β- unsaturated esters and amides catalyzed by R-(+) BINOL-lanthanide complexes affords corresponding 3-aryl-2-isoxazolines with
Synthesis and reactivity of carbohydroximoyl azides: I. Aliphatic and aromatic carbohydroximoyl azides and 5-substituted 1-hydroxytetrazoles based thereon
Tselinskii,Mel'nikova,Romanova
, p. 430 - 436 (2007/10/03)
Chlorination of 1-hydroxyiminopentane gave 1-chloro-1-nitrosopentane which reacted with sodium azide in DMF to form pentanohydroximoyl azide. The azidation of benzohydroximoyl chlorides was always accompanied by decomposition to benzonitriles. Treatment of carbohydroximoyl azides in ether with gaseous hydrogen chloride afforded 5-butyl-and 5-aryl-1-hydroxytetrazoles which reacted with acetic anhydride to form the corresponding acetates.
