38259-63-1Relevant academic research and scientific papers
Regioselective Synthesis of Trisubstituted Quinoxalines Mediated by Hypervalent Iodine Reagents
Ito, Ryota,Miura, Kasumi,Suzuki, Noriyuki,Suzuki, Yumiko,Takehara, Ren
, p. 16892 - 16900 (2021/12/06)
A facile and regioselective synthesis of quinoxalines, an important motif in medicinal chemistry and materials sciences, was developed. Despite their prospective utility, the regioselective preparation of trisubstituted quinoxalines has not been previously established. In the reported system, hypervalent iodine reagents catalyzed the annulation between α-iminoethanones ando-phenylenediamines in a chemo/regioselective manner to afford trisubstituted quinoxalines. Excellent regioselectivities (6:1 to 1:0) were achieved using [bis(trifluoroacetoxy)iodo]benzene and [bis(trifluoroacetoxy)iodo]pentafluorobenzene as annulation catalysts.
Copper-mediated regioselective efficient direct ortho-nitration of anilide derivatives
Reddy Depa, Manmohan,Potla, Suneetha,Narkhede, Umesh C.,Jadhav, Vinod D.,Vidavalur, Siddaiah
supporting information, (2020/07/20)
The mild and readily available Cu(NO3)2 mediated ortho nitration of anilides with broad substrate using K2S2O8 as an oxidant in the absence of any other metal catalyst and nitrating agent under mild conditions was reported for the first time.
Synthesis of Structurally Diverse Benzotriazoles via Rapid Diazotization and Intramolecular Cyclization of 1,2-Aryldiamines
Faggyas, Réka J.,Sloan, Nikki L.,Buijs, Ned,Sutherland, Andrew
supporting information, p. 5344 - 5353 (2019/05/21)
An operationally simple method has been developed for the preparation of N-unsubstituted benzotriazoles by diazotization and intramolecular cyclization of a wide range of 1,2-aryldiamines under mild conditions, using a polymer-supported nitrite reagent and p-tosic acid. The functional group tolerance of this approach was further demonstrated with effective activation and cyclization of N-alkyl, -aryl, and -acyl ortho-aminoanilines leading to the synthesis of N1-substituted benzotriazoles. The synthetic utility of this one-pot heterocyclization process was exemplified with the preparation of a number of biologically and medicinally important benzotriazole scaffolds, including an α-amino acid analogue.
Copper-catalyzed mild nitration of protected anilines
Hernando, Elier,Castillo, Rafael R.,Rodríguez, Nuria,G?mez Arrayás, Ram?n,Carretero, Juan C.
supporting information, p. 13854 - 13859 (2016/02/18)
A practical copper-catalyzed direct nitration of protected anilines, by using one equivalent of nitric acid as the nitrating agent, has been developed. This procedure features mild reaction conditions, wide structural scope (with regard to both N-protecting group and arene substitution), and high functional-group tolerance. Dinitration with two equivalents of nitric acid is also feasible. Practical and reliable: A Cu-catalyzed selective nitration of para- and ortho-substituted aniline derivatives by using one equivalent of HNO3 has been developed that produces water as the only stoichiometric byproduct (see scheme; PG=protecting group). This method is compatible with strongly electron-deficient substrates, enabling dinitration (by using 2.0 equiv of HNO3). This method allows for a rapid access to relevant nitrogen-containing heterocyclic architectures.
Reaction of N-Aryl- and N-Alkyl-benzimidoyl Chlorides with Silver Nitrate
Iley, Jim,Carvalho, Emilia,Norberto, Fatima,Rosa, Eduarda
, p. 281 - 290 (2007/10/02)
N-Arylbenzimidoyl chlorides, in which the N-aryl group is unsubstituted at the ortho- and para-positions, react with AgNO3 to yield N-(nitroaryl)benzamides, in which the NO2 group resides in the ortho- or para-position.N-Arylbenzimidoyl chlorides, in which the N-aryl ring is 2,4,6-trisubstituted, react with AgNO3 to yield the corresponding N-aryl-N-nitrobenzamides.The formation of both types of product can be explained by the intermediacy of an O-nitro imidate.Spectroscopic and chemical evidence is presented for the formation of this intermediate in the reaction of N-(2,4,6-trisubstituted phenyl)benzimidoyl chlorides with AgNO3.Rearrangement of the O-nitro imidate is unimolecular and intramolecular.The rate of rearrangement is independent of the substituent in the C-aryl ring, but increases with the electon-withdrawing ability of the substituents in the N-aryl ring.A mechanism is proposed in which the imidoyl chloride reacts with AgNO3 to produce first a nitrilium ion which goes on to form an O-nitro imidate that subsequently rearranges via a homolytic cleavage of the O-NO2 bond.The ortho:para ratios of N-(nitroaryl)benzamides obtained in the present work indicate that O-nitro imidates are not responsible for the high 1/2ortho:para ratios sometimes observed in the nitration of anilides.N-Alkylbenzimidoyl chlorides react with AgNO3 to form the corresponding N-nitro- and N-nitrosobenzamides.The mechanism of formation of the N-alkyl-N-nitrobenzamide arises from a pathway analogous to that for N-aryl-N-nitrobenzamides, involving a nitrilium ion that gives rise to an O-nitro imidate.The evidence for the formation of the N-nitrosobenzamide points to an alternative reaction of the imidoyl chloride with AgNO3.One possible mechanism for this reaction is described.
