13481-33-9Relevant academic research and scientific papers
Highly chemoselective deoxygenation of N-heterocyclic: N -oxides under transition metal-free conditions
Kim, Se Hyun,An, Ju Hyeon,Lee, Jun Hee
supporting information, p. 3735 - 3742 (2021/05/04)
Because their site-selective C-H functionalizations are now considered one of the most useful tools for synthesizing various N-heterocyclic compounds, the highly chemoselective deoxygenation of densely functionalized N-heterocyclic N-oxides has received much attention from the synthetic chemistry community. Here, we provide a protocol for the highly chemoselective deoxygenation of various functionalized N-oxides under visible light-mediated photoredox conditions with Na2-eosin Y as an organophotocatalyst. Mechanistic studies imply that the excited state of the organophotocatalyst is reductively quenched by Hantzsch esters. This operationally simple technique tolerates a wide range of functional groups and allows high-yield, multigram-scale deoxygenation. This journal is
Photo-redox catalyzed dehydrazinative acylation of N-heterocycles: Via Minisci reaction
Hafeez, Saira,Saeed, Aamer
, p. 38683 - 38689 (2021/12/20)
Visible light-induced acylation of heteroaromatic compounds have been achieved using benzoyl hydrazides as an efficient acyl source under mild reaction conditions. The photo-redox catalyzed oxidative cleavage of hydrazides leads to in situ formation of ac
Acyl Radicals from Terminal Alkynes: Photoredox-Catalyzed Acylation of Heteroarenes
Sultan, Shaista,Rizvi, Masood Ahmad,Kumar, Jaswant,Shah, Bhahwal Ali
supporting information, p. 10617 - 10620 (2018/07/31)
A photoredox-mediated acylation reaction of electron deficient heteroarenes with terminal alkynes is reported. The method relies on oxidative cleavage of phenylacetylenes for generation of acyl radicals as a key enabling feature. The reaction is regiosele
Oxidant-Controlled C-sp2/sp3-H Cross-Dehydrogenative Coupling of N-Heterocycles with Benzylamines
Sharma, Rohit,Abdullaha, Mohd,Bharate, Sandip B.
, p. 9786 - 9793 (2017/09/23)
Oxidant controlled ionic liquid mediated cross-dehydrogenative coupling (CDC) of benzylamines with N-heterocycles having sp2 or sp3 carbon resulted in the formation of C-benzoylated or alkenylated products. Benzoylation of N-heterocycles occurs via (NH4)2S2O8 catalyzed benzoyl radical formation. An oxidative alkenylation of N-heterocycles having C-sp3 carbon (2-methylaza-arenes) occurs via deamination of benzylamine followed by C-sp3-H bond activation in high stereoselectivity. Both benzoylation and alkenylation protocols are metal-free, green, simple, efficient, and tolerate a wide variety of functional groups.
TBHP/TFA mediated oxidative cross-dehydrogenative coupling of N-heterocycles with aldehydes
Chen, Jiayu,Wan, Miao,Hua, Jing,Sun, Yi,Lv, Zheng,Li, Wei,Liu, Lei
, p. 11561 - 11566 (2015/12/04)
An effective and metal-free oxidative cross-dehydrogenative coupling (CDC) of N-heterocycles with diverse aldehydes has been established in the presence of TBHP/TFA. The scope with respect to aldehyde and N-heterocycle components is broad, allowing facile synthesis of a broad range of structurally diverse C1-acyl substituted heterocycles in good efficiency.
Gold-Catalyzed Ring Expansion of Alkynyl Heterocycles through 1,2-Migration of an Endocyclic Carbon-Heteroatom Bond
Chen, Ming,Sun, Ning,Xu, Wei,Zhao, Jidong,Wang, Gaonan,Liu, Yuanhong
supporting information, p. 18571 - 18575 (2016/01/26)
A mild and efficient gold-catalyzed oxidative ring-expansion of a series of alkynyl heterocycles using pyridine-N-oxide as the oxidant has been developed, which affords highly valuable six- or seven-membered heterocycles with wide functional group toleration. The reaction consists of a regioselective oxidation and a chemoselective migration of an endocyclic carbon-heteroatom bond (favored over C-H migration) with the order of migratory aptitude for carbon-heteroatom bonds being C-S>C-N>C-O. In the absence of an oxidant, polycyclic products are readily constructed through a ring-expansion/Nazarov cyclization reaction sequence.
Regiospecific benzoylation of electron-deficient n -heterocycles with methylbenzenes via a minisci-type reaction
Ali, Wajid,Behera, Ahalya,Guin, Srimanta,Patel, Bhisma K.
, p. 5625 - 5632 (2015/06/16)
A regioselective cross-dehydrogenative coupling between electron-deficient N-heterocycles (isoquinoline, quinolines, and quinoxalines) and methylbenzenes leading to regiospecific C-aroylation has been accomplished using AlCl3 as the catalyst in
A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
Mamedov, Vakhid A.,Zhukova, Nataliya A.,Syakaev, Victor V.,Gubaidullin, Aidar T.,Beschastnova, Tat'Yana N.,Adgamova, Dil'Bar I.,Samigullina, Aida I.,Latypov, Shamil K.
supporting information, p. 1403 - 1416 (2013/02/23)
A highly efficient and versatile method for the synthesis of quinoxaline derivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange, conformational, and/or tautomeric exchanges between several forms for most of the bis-benzimidazolylquinoxalines signals of bridged and neighboring carbon atoms and the hydrogen atoms of the neighboring carbon atoms of benzimidazole fragments in the NMR spectra are broadened. The conjugation between the benzimidazole fragments and the quinoxaline core of the molecules is increased from the quinoxaline derivative (10c) to its thiadiazol[f]- (17) and pyrrolo[a]-(19) annulated derivatives, resulting in a greater planarity of the molecule as a whole.
Organocatalytic C-H bond arylation of aldehydes to bis-heteroaryl ketones
Toh, Qiao Yan,McNally, Andrew,Vera, Silvia,Erdmann, Nico,Gaunt, Matthew J.
supporting information, p. 3772 - 3775 (2013/04/24)
An organocatalytic aldehyde C-H bond arylation process for the synthesis of complex heteroaryl ketones has been developed. By exploiting the inherent electrophilicity of diaryliodonium salts, we have found that a commercial N-heterocyclic carbene catalyst promotes the union of heteroaryl aldehydes and these heteroaromatic electrophile equivalents in good yields. This straightforward catalytic protocol offers access to ketones bearing a diverse array of arene and heteroarene substituents that can subsequently be converted into molecules displaying structural motifs commonly found in medicinal agents.
Acetonitrile Derivatives as Carbonyl Synthons. One-Pot Preparation of Diheteroaryl Ketones via a Strategy of Sequential SNAr Substitution and Oxidation
Yin, Zhiwei,Zhang, Zhongxing,Kadow, John F.,Meanwell, Nicholas A.,Wang, Tao
, p. 1364 - 1367 (2007/10/03)
The anion of 2-aryl acetonitrile derivatives reacted with a variety of heteroaryl chlorides or bromides in an SNAr manifold to afford intermediate anions which were susceptible to oxidation. The addition of sodium peroxide and aqueous NH4OAc solution effected oxidation to afford aryl heteroaryl ketones in good yields. Aryl acetonitrile derivatives are thus umpolung-type synthons of the corresponding aryl carbonyl functionality.
