936-58-3Relevant articles and documents
Visible Light-Promoted Recyclable Carbon Nitride-Catalyzed Dioxygenation of β,γ-Unsaturated Oximes
Fu, Xiao-Yang,Si, Ya-Feng,Qiao, Li-Peng,Zhao, Yu-Fen,Chen, Xiao-Lan,Yu, Bing
supporting information, p. 574 - 580 (2021/11/13)
A visible-light-induced dioxygenation of β,γ-unsaturated oximes for the synthesis of diverse useful isoxazolines bearing a hydroxyl moiety was developed by employing graphitic carbon nitride (g-C3N4) as a heterogeneous photocatalyst under an air atmosphere. Noted that, the eminent advantages of this metal-free protocol include step economy, easy operation, a recyclable photocatalyst, external reductant-/oxidant-free and mild reaction conditions. Additionally, mechanistic studies indicated hydroxyl radical was generated under the photocatalysis of g-C3N4.
Chiral bipyridine-annulated bicyclo[3.3.1]nonane N-oxide organocatalysts for stereoselective allylation and hydrosilylation reactions
?eimyt?, Simona,Ston?ius, Sigitas
supporting information, (2020/12/21)
The synthesis of chiral C2-symmetric bis(bipyridine N,N′-dioxide) and bis(bipyridine N-monooxide) derivatives featuring bipyridine-annulated bicyclo[3.3.1]nonane framework is reported. The new Lewis basic bipyridine N,N′-dioxides exhibited good
Emergence of Highly Enantioselective Catalytic Activity in a Helical Polymer Mediated by Deracemization of Racemic Pendants
Ikai, Tomoyuki,Ando, Mitsuka,Ito, Masaki,Ishidate, Ryoma,Suzuki, Nozomu,Maeda, Katsuhiro,Yashima, Eiji
supporting information, p. 12725 - 12735 (2021/08/24)
Any polymers composed of racemic repeating units are obviously optically inactive and hence chiral functions, such as asymmetric catalysis, will not be expected at all. Contrary to such a preconceived notion, we report an unprecedented helical polymer-based highly enantioselective organocatalyst prepared by polymerization of a racemic monomer with no catalytic activity. Both the right- and left-handed helical poly(biarylylacetylene)s (PBAs) composed of dynamically racemic 2-arylpyridyl-N-oxide monomer units with N-oxide moieties located in the vicinity of the helical polymer backbone can be produced by noncovalent interaction with a chiral alcohol through deracemization of the biaryl pendants. The macromolecular helicity and the axial chirality induced in the PBAs are retained ("memorized") after complete removal of the chiral alcohol. Accordingly, the helical PBAs with dual static memory of the helicity and axial chirality show remarkable enantioselectivity (86% ee) for the asymmetric allylation of benzaldehyde. The enantioselectivity is slightly lower than that (96% ee) of the homochiral PBAs prepared from the corresponding enantiopure (R)- and (S)-monomers, but is comparable to that (88% ee) of the helical PBA composed of nonracemic monomers of ca. 60% ee.
Nickel-Catalyzed Reductive Allylation of Aldehydes with Allyl Acetates
Suzuki, Hiroyuki,Yamaguchi,Itoh, Akichika
, p. 1489 - 1494 (2020/12/13)
Carbonyl allylation reactions constitute an important step in the formation of carbon-carbon reactions, and involve various related reactions that chiefly use allylmetal reagents. This report presents a nickel-catalyzed carbonyl allylation reaction using allyl acetate, which produces homoallyl alcohols in moderate to good yields, as an efficient methodology under reductive coupling conditions.
Catalytic Photoredox Allylation of Aldehydes Promoted by a Cobalt Complex
Gualandi, Andrea,Rodeghiero, Giacomo,Perciaccante, Rossana,Jansen, Thomas Paul,Moreno-Cabrerizo, Cristina,Foucher, Charles,Marchini, Marianna,Ceroni, Paola,Cozzi, Pier Giorgio
supporting information, p. 1105 - 1111 (2021/01/04)
The preparation of homoallylic alcohols by addition of organometallic allyl compounds to carbonyls is an important strategy in organic chemistry. Allylating organometallic cobalt species can be generated employing stoichiometric quantities of Zn acting as reductant. To avoid the employment of stoichiometric amount of Zn, we have developed an allylation reaction of aromatic and aliphatic aldehydes promoted by photoredox catalysis in the presence of a cobalt complex, and we present herein a full account of our research. In the presence of the abundant CoBr2 (10 mol %), 4,4′-di-tert-butyl-2,2′-dipyridyl (dtbbpy, 10 mol %), allyl acetate (3 equiv.), [Ir(dtbbpy)(ppy)2]PF6 (ppy=2-phenylpyridine, 2 mol %), and N,N-diisopropylethylamine (4 equiv.), an allylation of aldehydes is taking place, in moderate to good yields. Substrates scope, limitations, and photophysical investigations of this new process are reported. (Figure presented.).
Photocatalytic Umpolung Synthesis of Nucleophilic π-Allylcobalt Complexes for Allylation of Aldehydes
Shi, Caizhe,Li, Fusheng,Chen, Yuqing,Lin, Shuangjie,Hao, Erjun,Guo, Zhuowen,Wosqa, Urwa Tul,Zhang, Dandan,Shi, Lei
, p. 2992 - 2998 (2021/03/09)
The concept of "umpolung"reactivity of π-allylmetal complexes has been developed as a powerful method for the allylation of aldehydes. This paper describes the photocatalytic umpolung strategy for the synthesis of nucleophilic allylcobalt complexes through a single-electron-transfer (SET) process. This strategy enables the metallaphotoredox allylation of carbonyls with allyl acetate using organic N,N-diisopropylethylamine as the terminal reductant bypassing the use of a stoichiometric amount of metals. Ultraviolet-visible spectroscopy was used to monitor the redox changes of cobalt in the reaction.
Indium-mediated allylation of carbonyl compounds in deep eutectic solvents
González-Gallardo, Nerea,Saavedra, Beatriz,Guillena, Gabriela,Ramón, Diego J.
, (2021/08/26)
This study describes, for the first time, the in situ generation of indium organometallic reagents in environmentally friendly deep eutectic solvents (DESs). The allylation process of different carbonyl compounds is achieved mediated by indium metal and u
Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2)?H Bonds
Chang, Xiao-Yong,Chen, Ji-Jun,Gu, Qiang-Shuai,Jiang, Sheng-Peng,Li, Zhong-Liang,Liu, Lin,Liu, Xiao-Dong,Liu, Xin-Yuan,Su, Xiao-Long,Wang, Fu-Li,Yang, Chang-Jiang,Ye, Liu
supporting information, p. 380 - 384 (2020/10/30)
The development of enantioconvergent cross-coupling of racemic alkyl halides directly with heteroarene C(sp2)?H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)?H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α-chiral alkylated azoles, such as 1,3,4-oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4-triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)?H bond and the involvement of alkyl radical species under the reaction conditions.
Remote Arylative Substitution of Alkenes Possessing an Acetoxy Group via β-Acetoxy Elimination
Kakiuchi, Fumitoshi,Kochi, Takuya,Kumagai, Takaaki,Muto, Kazuma
supporting information, p. 24500 - 24504 (2021/10/19)
Palladium-catalyzed remote arylative substitution was achieved for the reaction of arylboronic acids with alkenes possessing a distant acetoxy group to provide arylation products having an alkene moiety at the remote position. The use of β-acetoxy elimination as a key step in the catalytic cycle allowed for regioselective formation of unstabilized alkenes after chain walking. This reaction was applicable to various arylboronic acids as well as alkene substrates.
Structure-Activity Studies of Truncated Latrunculin Analogues with Antimalarial Activity
Varghese, Swapna,Rahmani, Rapha?l,Drew, Damien R.,Beeson, James G.,Baum, Jake,Smith, Brian J.,Baell, Jonathan B.
, p. 679 - 693 (2020/11/30)
Malarial parasites employ actin dynamics for motility, and any disruption to these dynamics renders the parasites unable to effectively establish infection. Therefore, actin presents a potential target for malarial drug discovery, and naturally occurring actin inhibitors such as latrunculins are a promising starting point. However, the limited availability of the natural product and the laborious route for synthesis of latrunculins have hindered their potential development as drug candidates. In this regard, we recently described novel truncated latrunculins, with superior actin binding potency and selectivity towards P. falciparum actin than the canonical latrunculin B. In this paper, we further explore the truncated latrunculin core to summarize the SAR for inhibition of malaria motility. This study helps further understand the binding pattern of these analogues in order to develop them as drug candidates for malaria.
