493-62-9Relevant academic research and scientific papers
Highly efficient modular metal-free synthesis of 3-substituted 2-quinolones
Aksenov, Alexander V.,Smirnov, Alexander N.,Aksenov, Nicolai A.,Aksenova, Inna V.,Bijieva, Asiyat S.,Rubin, Michael
, p. 9786 - 9788 (2014)
A modular approach to 3-substituted 2-quinolones via a cascade annulation reaction between 4-nitroketones and hydrazines has been developed.
Direct Palladium-Catalyzed β-Arylation of Lactams
Chen, Ming,Liu, Feipeng,Dong, Guangbin
, p. 3815 - 3819 (2018)
A direct and catalytic method is reported here for β-arylation of N-protected lactams with simple aryl iodides. The transformation is enabled by merging soft enolization of lactams, palladium-catalyzed desaturation, Ar?X bond activation, and aryl conjugate addition. The reaction is operated under mild reaction conditions, is scalable, and is chemoselective. Application of this method to concise syntheses of pharmaceutically relevant compounds is demonstrated.
Synthesis, photophysical properties, and application of o - And p -amino green fluorescence protein synthetic chromophores
Chen, Yi-Hui,Lo, Wei-Jen,Sung, Kuangsen
, p. 301 - 310 (2013)
The o- and p-amino green-fluorescence-protein synthetic chromophores (GFPSCs) were synthesized from the corresponding o- and p-nitro protecting group. Among the four protecting groups of the o-amino group, the o-nitro protecting group is the only choice to synthesize the o-amino GFPSCs. The first singlet excited states of o- and p-amino GFPSCs carry significant charge-transfer character through the mechanism of photoinduced charge transfer (PCT). The o-amino GFPSCs can serve as wavelength-ratiometric fluorescence sensors that selectively recognize Cr3+ in aqueous medium through a PCT mechanism.
Dehalogenation and barbier-type hydroxyalkylation of π-deficient haloheterocycles using indium
Fukuda, Eri,Takahashi, Yukiko,Hirasawa, Natsumi,Sugimoto, Osamu,Tanji, Ken-Ichi
, p. 1163 - 1170 (2009)
The reaction of π-deficient haloheterocycles with indium metal in water gave corresponding dehalogenated heterocycles. The use of diluted hydrochloric acid instead of water accelerated the reductive reactivity of indium metal. Furthermore, Barbier-type additions proceeded by reactions of α-iodoheterocycles with indium in the presence of pivalaldehyde.
Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis
Zhou, Min-Jie,Zhang, Lei,Liu, Guixia,Xu, Chen,Huang, Zheng
supporting information, p. 16470 - 16485 (2021/10/20)
The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.
Iron-Catalyzed ?±,?-Dehydrogenation of Carbonyl Compounds
Zhang, Xiao-Wei,Jiang, Guo-Qing,Lei, Shu-Hui,Shan, Xiang-Huan,Qu, Jian-Ping,Kang, Yan-Biao
supporting information, p. 1611 - 1615 (2021/03/03)
An iron-catalyzed α,β-dehydrogenation of carbonyl compounds was developed. A broad spectrum of carbonyls or analogues, such as aldehyde, ketone, lactone, lactam, amine, and alcohol, could be converted to their α,β-unsaturated counterparts in a simple one-step reaction with high yields.
Efficient visible light mediated synthesis of quinolin-2(1H)-ones from quinolineN-oxides
Bhuyan, Samuzal,Chhetri, Karan,Hossain, Jagir,Jana, Saibal,Mandal, Susanta,Roy, Biswajit Gopal
supporting information, p. 5049 - 5055 (2021/07/29)
Quinolin-2(1H)-ones are one of the important classes of compounds due to their prevalence in natural products and in pharmacologically useful compounds. Here we present an unconventional and hitherto unknown photocatalytic approach to their synthesis from easily available quinoline-N-oxides. This reagent free highly atom economical photocatalytic method, with low catalyst loading, high yield and no undesirable by-product, provides an efficient greener alternative to all conventional synthesis reported to date. The robustness of the methodology has been successfully demonstrated with easy scaling up to the gram scale.
Manganese-Promoted Regioselective Direct C3-Phosphinoylation of 2-Pyridones
Chantarojsiri, Teera,Kittikool, Tanakorn,Phakdeeyothin, Kunita,Yotphan, Sirilata
supporting information, p. 3071 - 3078 (2021/07/22)
A highly efficient and regioselective manganese-induced radical oxidative direct C?P bond formation between 2-pyridones and secondary phosphine oxides was developed. The C3-selective phosphinoylation was conveniently achieved through a combination of substoichiometric manganese and persulfate oxidant under mild conditions. Various 3-phosphinoylated pyridone products can be obtained in moderate to high yields. Preliminary mechanistic studies suggest that the reaction is likely to involve a radical pathway induced by catalytically active Mn3+ species.
Solvent-Dependent Cyclization of 2-Alkynylanilines and ClCF2COONa for the Divergent Assembly of N-(Quinolin-2-yl)amides and Quinolin-2(1 H)-ones
Wang, Ya,Zhou, Yao,Ma, Xingxing,Song, Qiuling
, p. 5599 - 5604 (2021/08/01)
Herein, we present an expedient Cu-catalyzed [5 + 1] cyclization of 2-alkynylanilines and ClCF2COONa to divergent construction of N-(quinolin-2-yl)amides and quinolin-2(1H)-ones by regulating the reaction solvents. Notably, nitrile acts as a solvent and performs the Ritter reactions. ClCF2COONa is used as a C1 synthon in this transformation, which also represents the first example for utilization of ClCF2COONa as an efficient desiliconization reagent. The current protocol involves in situ generation of isocyanide, copper-activated alkyne, Ritter reaction and protonation.
Facile N-Formylation of Amines on Magnetic Fe3O4?CuO Nanocomposites
Datta Khanal, Hari,Mishra, Kanchan,Rok Lee, Yong
, p. 4477 - 4484 (2021/08/30)
A facile, eco-friendly, efficient, and recyclable heterogeneous catalyst is synthesized by immobilizing copper impregnated on mesoporous magnetic nanoparticles. The surface chemistry analysis of Fe3O4?CuO nanocomposites (NCs) by XRD and XPS demonstrates the synergistic effect between Fe3O4 and CuO nanoparticles, providing mass-transfer channels for the catalytic reaction. TEM images clearly indicate the impregnation of CuO onto mesoporous Fe3O4. This hydrothermally synthesized eco-friendly and highly efficient Fe3O4?CuO NCs are applied as a magnetically retrievable heterogeneous catalyst for the N-formylation of wide range of aliphatic, aromatic, polyaromatic and heteroaromatic amines using formic acid as a formylating agent at room temperature. The catalytic activity of the NCs for N-formylation is attributable to the synergistic effect between Fe3O4 and CuO nanoparticles. The N-formylated product is further employed for the synthesis of biologically active quinolone moieties.
