59-31-4Relevant academic research and scientific papers
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.
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.
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
supporting information, 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.
A photochemical C=C cleavage process: Toward access to backbone N-formyl peptides
Ball, Zachary T.,Wang, Haopei
supporting information, p. 2932 - 2938 (2022/01/12)
Photo-responsive modifications and photo-uncaging concepts are useful for spatiotemporal control of peptides structure and function. While side chain photo-responsive modifications are relatively common, access to photo-responsive modifications of backbone N-H bonds is quite limited. This letter describes a new photocleavage pathway, affording N-formyl amides from vinylogous nitroaryl precursors under physiologically relevant conditions via a formal oxidative C=C cleavage. The N-formyl amide products have unique properties and reactivity, but are difficult or impossible to access by traditional synthetic approaches.
Identification of N-acyl quinolin-2(1H)-ones as new selective agents against clinical isolates of Acanthamoeba keratitis
Abad-Grillo, Teresa,Lorenzo-Morales, Jacob,McNaughton-Smith, Grant,Freijo, Mónica Blanco,López-Arencibia, Atteneri,Pi?ero, José E.,Reyes-Batlle, María
, (2020/04/08)
A collection of N-substituted quinolin-2(1H)-ones were screened against a panel of clinically relevant protozoa (Leishmania, Trypanosoma and Acanthamoeba). Three quinolin-2(1H)-one compounds were identified as selective anti-Acanthamoeba agents. Further assessment revealed that these compounds were active against both trophozoite and cyst forms of A. castellanii Neff, and caused protozoa death via apoptosis. The data presented herein identify N-acyl quinolin-2(1H)-ones as a promising new class of selective anti-Acanthamoeba agents.
Palladium-Catalyzed Hydroxylation of Aryl Halides with Boric Acid
Song, Zhi-Qiang,Wang, Dong-Hui
supporting information, p. 8470 - 8474 (2020/11/18)
Boric acid, B(OH)3, is proved to be an efficient hydroxide reagent in converting (hetero)aryl halides to the corresponding phenols with a Pd catalyst under mild conditions. Various phenol products were obtained in good to excellent yields. This transformation tolerates a broad range of functional groups and molecules, including base-sensitive substituents and complicated pharmaceutical (hetero)aryl halide molecules.
Multi-Functional Oxidase Activity of CYP102A1 (P450BM3) in the Oxidation of Quinolines and Tetrahydroquinolines
Li, Yushu,Wong, Luet L.
, p. 9551 - 9555 (2019/08/06)
Tetrahydroquinoline, quinoline, and dihydroquinolinone are common core motifs in drug molecules. Screening of a 48-variant library of the cytochrome P450 enzyme CYP102A1 (P450BM3), followed by targeted mutagenesis based on mutation-selectivity correlations from initial hits, has enabled the hydroxylation of substituted tetrahydroquinolines, quinolines, and 3,4-dihydro-2-quinolinones at most positions around the two rings in good to high yields at synthetically relevant scales (1.5 g L?1 day?1). Other oxidase activities, such as C?C bond desaturation, aromatization, and C?C bond formation, were also observed. The enzyme variants, with mutations at the key active site residues S72, A82, F87, I263, E267, A328, and A330, provide direct and sustainable routes to oxy-functionalized derivatives of these building block molecules for synthesis and drug discovery.
