17572-77-9Relevant academic research and scientific papers
Palladium complex catalyzed acylation of allylic esters with acylstannanes: Complementary method to the acylation with acylsilanes
Obora, Yasushi,Nakanishi, Masafumi,Tokunaga, Makoto,Tsuji, Yasushi
, p. 5835 - 5837 (2002)
Palladium-catalyzed acylation of allylic trifluoroacetates (2) using acylstannanes (1) is reported. The reaction serves as a complementary method to the previously reported acylation with acylsilane (4). In particular, the reaction is profitable in the acylation of unsubstituted allyl trifluoroacetate (2a) and benzoylation of allylic trifluoroacetates to afford synthetically useful β,γ-unsaturated ketones (3) in good yields without undesirable isomerizations.
Base-catalyzed cascade dimerization of γ-aryl-β,γ-enones into acylated terphenyls
Schmidt, Elena Yu.,Tatarinova, Inna V.,Ushakov, Igor A.,Trofimov, Boris A.
, p. 378 - 379 (2016)
4-Aryl-1-(het)arylbut-3-en-1-ones dimerize smoothly in the ButOK/DMSO superbase system at 100?°C for 4 h to afford acylated terphenyls in up to 79% yield. The dimerization is accompanied by elimination of the methylarene molecule.
Samarium dienolate mediated stereoselective synthesis of anti-1,3-diol monoesters via aldol-Tishchenko reaction
Reutrakul, Vichai,Jaratjaroonphong, Jaray,Tuchinda, Patoomratana,Kuhakarn, Chutima,Kongsaeree, Palangpon,Prabpai, Samran,Pohmakotr, Manat
, p. 4753 - 4757 (2006)
The reaction of an (E)-samarium dienolate, generated by the regioselective reductive cleavage of a phenylsulfonyl activated cyclopropyl ketone with samarium(II) iodide, with aliphatic and aromatic aldehydes gives the 2-substituted anti-1,3-diol monoester
Photolysis of acetophenone derivatives with α-cyclopropyl substituents
Ranaweera, Ranaweera A.A. Upul,Weragoda, Geethika K.,Bain, John,Watanabe, Shinji,Abe, Manabu,Gudmundsdottir, Anna D.
, p. 137 - 146 (2015)
Laser flash photolysis of cyclopropyl(phenyl)methanone 6 in argon-saturated methanol yields the triplet ketone (T1K) of 6 that is formed with a rate constant of ～1.7×107s-1 (λmax = 360nm) and has a lifetime of ～1.4 μs. T1K of 6 decays to form ketyl radical 7 (λmax ～300nm), which dimerizes to form photoproducts, pinacol derivatives 8 and 9. In comparison, photolysis of trans-phenyl(2-phenylcyclopropyl)methanone 1 in argon-saturated chloroform-d results in cis-phenyl (2-phenylcyclopropyl)methanone 2 and a smaller amount of 3, presumably through 1, 3-biradical 11. Nanosecond laser flash photolysis of 1 does not reveal significant transient absorption, although the T1K of 1 is detected with phosphorescence at 77K. Density functional theory calculations were used to elucidate the triplet reactivity of 1, 2 and 6 by comparing the feasibility of H atom abstraction, cyclopropyl cleavage and β-quenching of their triplet ketones.
Palladium complex catalyzed acylation of allylic esters with acylsilanes
Obora,Ogawa,Imai,Kawamura,Tsuji
, p. 10489 - 10493 (2001)
Acylation of allylic esters (2) with acylsilanes (1) in the presence of a catalytic amount (5 mol %) of a palladium complex is reported. The reaction proceeds selectively to afford β, γ-unsaturated ketones (3) in high yields. [Pd(η3-C6/su
Enantioselective γ-Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds
Wang, Xuemei,Zhou, Liang,Zhang, Hongkui,Ren, Xiaoyu,Gao, Guowei,Wang, Tianli
supporting information, p. 38 - 42 (2022/01/04)
A highly enantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation, and facile transformation. Moreover, mechanistic investigations provided insights into the reaction pathway and the origin of chiral induction.
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.
Regio- and Stereoselective Cascade of β,γ-Unsaturated Ketones by Dipeptided Phosphonium Salt Catalysis: Stereospecific Construction of Dihydrofuro-Fused [2,3-b] Skeletons
Chen, Yayun,He, Jiajia,Jiang, Chunhui,Ren, Xiaoyu,Su, Zhishan,Wang, Tianli,Xiao, Kai,Zhang, Hongkui,Zhuang, Cheng
supporting information, p. 19860 - 19870 (2021/08/06)
Chiral (dihydro)furo-fused heterocycles are significant structural motifs in numerous natural products, functional materials and pharmaceuticals. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we develop an effective, modular method by a dipeptide-phosphonium salt-catalyzed regio- and stereoselective cascade reaction of readily available linear β,γ-unsaturated ketones with aromatic alkenes, affording a wide variety of structurally fused heterocyclic molecules in high yields with excellent stereoselectivities. Moreover, mechanistic investigations revealed that the bifunctional phosphonium salt controlled the regio- and stereoselectivities of this cascade reaction, particularly proceeding through the initial ketone α-addition followed by O-participated substitution; and the multiple hydrogen-bonding interactions between Br?nsted acid moieties of catalyst and nitro group of aromatic alkene were crucial in asymmetric induction. Given the generality, versatility, and high efficiency of this method, we anticipate that it will have broad synthetic utilities.
Bioinspired Radical-Mediated Transition-Metal-Free Synthesis of N-Heterocycles under Visible Light
K. Bains, Amreen,Ankit, Yadav,Adhikari, Debashis
, p. 324 - 329 (2020/11/30)
A redox-active iminoquinone motif connected with π-delocalized pyrene core has been reported that can perform efficient two-electron oxidation of a class of substrates. The design of the molecule was inspired by the organic redox cofactor topaquinone (TPQ), which executes amine oxidation in the enzyme, copper amine oxidase. Easy oxidation of both primary and secondary alcohols happened in the presence of catalytic KOtBu, which could reduce the ligand backbone to its iminosemiquinonate form under photoinduced conditions. Moreover, this easy oxidation of alcohols under aerobic condition could be elegantly extended to multi-component, one-pot coupling for the synthesis of quinoline and pyrimidine. This organocatalytic approach is very mild (70 °C, 8 h) compared to a multitude of transition-metal catalysts that have been used to prepare these heterocycles. A detailed mechanistic study proves the intermediacy of the iminosemiquinonate-type radical and a critical hydrogen atom transfer step to be involved in the dehydrogenation reaction.
Method for synthesizing polysubstituted isoxazolidine
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Paragraph 0011; 0032-0035; 0060-0063, (2021/09/08)
The invention provides a method for synthesizing polysubstituted isoxazolidine, and relates to the technical field of biological medicines. The acetophenone and N -alkyl hydroxylamine derivative is a reaction raw material; in the aprotic polar solvent, th
