6637-33-8Relevant academic research and scientific papers
Selective synthesis of 2-indolyl-3-oxoindolines or 2-(2-aminophenyl)quinolines through Cu(II)- or Bi(III)-catalyzed tunable dimerizations of 2-alkynylanilines
Jia, Ruixue,Li, Bin,Zhang, Xinying,Fan, Xuesen
supporting information, p. 6810 - 6815 (2020/09/15)
A novel and selective synthesis of 2-indolyl-3-oxoindolines or 2-(2-aminophenyl)quinolines through tunable dimerizations of 2-alkynylanilines is presented. Mechanistically, the formation of 2-indolyl-3-oxoindolines involves a Cu(OAc)2/O2-promoted intramolecular cyclization of 2-alkynylaniline to give the required indole and 3H-indol-3-one intermediates followed by the indolylation of 3H-indol-3-one. On the other hand, the formation of 2-(2-aminophenyl)quinolines is believed to go through a Bi(OTf)3/MesCO2H-catalyzed intermolecular N-nucleophilic addition between two 2-alkynylaniline molecules to give an enamine intermediate followed by its intramolecular C-nucleophilic addition/annulation. Notable features of these new methods include easily obtainable substrates, economical catalysts and oxidant, controllable selectivity, and high versatility toward diverse products.
Unveiling reactive metal sites in a Pd pincer MOF: Insights into Lewis acid and pore selective catalysis
Reiner, Benjamin R.,Kassie, Abebu A.,Wade, Casey R.
supporting information, p. 9588 - 9595 (2019/07/09)
A porous Zr metal-organic framework, 1-PdBF4 [Zr6O4(OH)4(OAc)2.4{(PNNNP)Pd(MeCN)}2.4(BF4)2.4; PNNNP = 2,6-(HNPAr2)2C5H3N; Ar = p-C6H4CO2-], has been synthesized via postsynthetic oxidative I-/BF4- ligand exchange using NOBF4. 1-PdBF4 enjoys markedly superior catalytic activity and recyclability to its trifluoracetate-exchanged analogue, 1-PdTFA, for the intramolecular cyclization of o-alkynyl anilines and the carbonyl-ene cyclization of citronellal. Moreover, 1-PdBF4 demonstrates a rare example of pore selective catalysis for the cyclization of 2-ethynyl aniline.
Tunable synthesis of indolo[3,2- c]quinolines or 3-(2-Aminophenyl)Quinolines via aerobic/anaerobic dimerization of 2-alkynylanilines
Jia, Ruixue,Li, Bin,Liang, Rong,Zhang, Xinying,Fan, Xuesen
supporting information, p. 4996 - 5001 (2019/07/03)
In this paper, an unprecedented selective synthesis of indolo[3,2-c]quinoline or 3-(2-aminophenyl)quinoline derivatives through Rh(III)-catalyzed stepwise dimerization of 2-alkynylanilines under aerobic or anaerobic conditions is presented. Notably, hexafluoroisopropanol is found to be a crucial solvent and promoter for the success of these reactions. In addition, the utility of the products thus obtained was showcased by their facile transformations into the pharmaceutically and photophysically significant naphthyridine derivatives.
Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air
Yao, Song,Zhou, Kaijing,Wang, Jiabing,Cao, Hongen,Yu, Lei,Wu, Jianzhang,Qiu, Peihong,Xu, Qing
supporting information, p. 2945 - 2951 (2017/07/24)
By using air as the superior oxidant, a highly atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles. Effectively working as the promoter in the alcohol oxidation, nitrile hydration, and cyclocondensation steps, CsOH is the best base for the reaction. A similar method can also be extended to the synthesis of substituted quinolines starting from methyl ketones instead of nitriles.
Revisiting the Gold-Catalyzed Dimerization of 2-Ethynylanilines: A Room-Temperature and Silver-Free Protocol for the Synthesis of Multifunctional Quinolines
Praveen, Chandrasekar,Perumal
, p. 855 - 864 (2016/03/15)
A room temperature and silver-free protocol for the formation of quinolines from 2-ethynylanilines through a dimerization event was achieved using a dinuclear gold catalyst, Au2(BIPHEP)(NTf2)2. The reaction is inherently modular, allowing for the incorporation of peripheral substituents at any site of the quinoline product. The reaction is readily applied to other heterocyles also as exemplified by the preparation of naphthyridines. Competition reactions to determine the reactivity of dissimilar alkynes demonstrated that the product ratio of dimerization vs intermolecular addition is rather dependent on the electronic nature of aryl substituent on the alkynes. However, control experiments with substrates possessing internal alkynes resulted in cycloisomerization instead of expected dimerization, which is indicative of possible steric influence of the alkyne terminus in the reaction outcome.
A Ruthenium Catalyst with Unprecedented Effectiveness for the Coupling Cyclization of - Amino Alcohols and Secondary Alcohols
Pan, Bing,Liu, Bo,Yue, Erlin,Liu, Qingbin,Yang, Xinzheng,Wang, Zheng,Sun, Wen-Hua
, p. 1247 - 1253 (2016/02/18)
The ruthenium complex (8-(2-diphenylphosphinoethyl)aminotrihydroquinolinyl)(carbonyl)(hydrido)ruthenium chloride exhibited extremely high efficiency toward the coupling cyclization of -amino alcohols with secondary alcohols. The corresponding products, pyridine or quinoline derivatives, are obtained in good to high isolated yields. On comparison with literature catalysts whose noble-metal loading with respect to -amino alcohols reached 0.5-1.0 mol % for Ru and a record lowest of 0.04 mol % for Ir, the current catalyst achieves the same efficiency with a loading of 0.025 mol % for Ru. The mechanism of acceptorless dehydrogenative condensation (ADC) was proposed on the basis of DFT calculations; in addition, the reactive intermediates were determined by GC-MS, NMR, and single-crystal X-ray diffraction. The catalytic process is potentially suitable for industrial applications.
Regioselective Synthesis of C-3-Functionalized Quinolines via Hetero-Diels-Alder Cycloaddition of Azadienes with Terminal Alkynes
Saunthwal, Rakesh K.,Patel, Monika,Verma, Akhilesh K.
, p. 6563 - 6572 (2016/08/16)
A highly efficient metal and protection-free approach for the regioselective synthesis of C-3-functionalized quinolines from azadienes (in situ generated from 2-aminobenzyl alcohol) and terminal alkynes through [4 + 2] cycloaddition has been developed. An unprecedented reaction of 2-aminobenzyl alcohol with 1,3- and 1,4-diethynylbenzene provided the C-3 tolylquinolines via [4 + 2] HDA and oxidative decarboxylation. The -NH2 group directed mechanistic approach was well supported by the control experiments and deuterium-labeling studies and by isolating the azadiene intermediate. The reactivity and selectivity of unprotected azadiene in metal-free base-assisted hetero-Diels-Alder reaction is exploited to quickly assemble an important class of C-3-functionalized quinolines, which are difficult to access.
A Sc(OTf)3-catalyzed cascade reaction of o-aminoacetophenone with methanamine: Construction of dibenzo[b,h][1,6]naphthyridine derivatives
Mao, Dan,Tang, Jun,Wang, Wenbo,Liu, Xin,Wu, Shengying,Yu, Jianjun,Wang, Limin
supporting information, p. 2122 - 2128 (2015/03/05)
An unexpected Sc(OTf)3-catalyzed and air-mediated cascade reaction of o-aminoacetophenones with methanamines was discovered as an efficient synthetic approach to a novel class of fluorescent fused-four-ring dibenzo[b,h][1,6]naphthyridine derivatives. Two possible mechanisms of the reaction were proposed. The photophysical properties of the dibenzo[b,h][1,6]naphthyridine 1a were initially considered. This journal is
Metal-free aerobic one-pot synthesis of substituted/annulated quinolines from alcohols via indirect Friedl?nder annulation
Anand, Namrata,Koley, Suvajit,Ramulu, B. Janaki,Singh, Maya Shankar
supporting information, p. 9570 - 9574 (2015/09/28)
Metal-free, operationally simple, and highly efficient one-pot aerobic process for the synthesis of functionalized/annulated quinolines is devised from easily available 2-aminobenzyl alcohol/2-aminobenzophenones and alkyl/aryl alcohols for the first time. The process involves two sequential reactions, namely in situ aerial oxidation of alcohols to the corresponding aldehydes/ketones followed by Friedl?nder annulation.
Synthesis of polysubstituted analogues of the 4-methyl-2-phenylquinoline
Al-Qahtani,Al-Turki,Khan,Mousa,Alkhathlan
, p. 6055 - 6058 (2013/07/26)
A simple and convenient synthetic method for the direct synthesis of a series of polysubstituted analogues of the putative antifungal agent 4-methyl-2-phenylquinoline, a mimic of the natural bioactive 4-methoxy-2-phenylquinoline is reported.
