7443-25-6Relevant academic research and scientific papers
A novel sublimable organic salt: Synthesis, characterization, thermal behavior, and catalytic activity for the synthesis of arylidene, heteroarylidene, and alkylidene malonates
Gorjian, Hayedeh,Johan, Mohd R.,Johari, Suzaimi,Khaligh, Nader G.,Zaharani, Lia
, (2021/09/18)
A novel sublimable organic salt was synthesized, and its chemical structure was characterized by FTIR, 1D NMR, 2D NMR, and elemental analysis. In addition, the thermal phase transitions and thermal stability of new organic salt were investigated. The DSC and TGA results showed that the organic salt could convert into constituent molecules at dec. ~ 200?°C) under atmospheric pressure without forming the liquid phase. Then, it was recondensed to regenerate the initial organic salt in the cool part of the vial. Therefore, it can be a promising organic salt towards the regeneration of spent catalyst from synthesis processes when the reaction mixture contains poorly volatile components and includes its use in gas-phase procedures. Also, the catalytic efficiency of new organic salt was investigated in the Knoevenagel condensation reaction. A variety of substituted arylidene and alkylidene malonates were isolated in 78–95% yield within six hours.? Under the optimized reaction conditions, the current catalytic procedure exhibited superiority compared to the mixed piperazine/acetic acid, piperidine/acetic acid, and piperidinium acetate. There were no significant changes in the new organic salt chemical structure and catalytic activity even after the 5th run. This work revealed the importance of the existence of simultaneous hydrogen bond acceptor/donor groups in our environmentally friendly catalyst to promote the Knoevenagel condensation reaction without the use of metal-containing catalysts.
Solid-phase synthesis of arylidene and alkylidene malonates, as versatile intermediates, catalyzed using mesoporous poly-melamine–formaldehyde as a nitrogen-rich porous organic polymer (POP)
Khaligh, Nader Ghaffari,Gorjian, Hayedeh,Fahim, Hoda,Titinchi, Salam J. J.
, p. 3529 - 3536 (2021/05/11)
An efficient solid/slurry-state synthesis of arylidene and alkylidene malonates as versatile intermediates is developed in the presence of mesoporous poly-melamine–formaldehyde. The condensation reaction was conducted through a ball milling process as a non-conventional procedure and a greener methodology at room temperature under solvent-free conditions. The mesoporous heterogeneous catalyst could be recovered and reused ten times, and the results showed a negligible loss of catalytic activity. Various aryl- and heteroarylidene malonates, as well as dimethyl (cyclohexylidene)malonate, were isolated in good to high yields under optimal conditions. The use of hazardous reagents and solvents were minimized in the current method, and separation of catalyst and products, as well as the recovery and reusing of catalyst, were performed by cost-effective procedures. This work revealed that the synergistic effect of numerous Lewis base sites together with acceptor-donner hydrogen bonding functional groups in porous organic polymer (POP), and its high porosity plays a vital role to promote the carbon–carbon coupling reaction in the solid phase synthesis.
Reductive Knoevenagel Condensation with the Zn-AcOH System
Ivanov, Konstantin L.,Melnikov, Mikhail Ya.,Budynina, Ekaterina M.
, p. 1285 - 1291 (2020/11/13)
An efficient gram-scale one-pot approach to 2-substituted malonates and related structures is developed, starting from commercially available aldehydes and active methylene compounds. The technique combines Knoevenagel condensation with the reduction of the C=C bond in the resulting activated alkenes with the Zn-AcOH system. The relative ease with which the C=C bond reduction occurs can be traced to the accepting abilities of the substituents in the intermediate arylidene malonates.
Acetal Addition to Electron-Deficient Alkenes with Hydrogen Atom Transfer as a Radical Chain Propagation Step
Chan, Wei Chuen,Vinod, Jincy K.,Koide, Kazunori
, p. 3674 - 3682 (2021/02/16)
We describe a visible-light-promoted addition of a hydrogen atom and an acetal carbon toward various electron-deficient alkenes. 1,3-Dioxolane is converted to its radical species in the presence of persulfate and an iridium catalyst upon visible light irradiation, which then reacts with electron-deficient alkenes. The reaction operates via a radical chain mechanism, a less commonly observed pathway for this class of transformation. Hydrogen atom transfer from 1,3-dioxolane to α-malonyl radicals is corroborated by experimental and density functional theory studies.
Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate
Andreev, Ivan A.,Ratmanova, Nina K.,Augustin, André U.,Ivanova, Olga A.,Levina, Irina I.,Khrustalev, Victor N.,Werz, Daniel B.,Trushkov, Igor V.
supporting information, p. 7927 - 7934 (2021/03/03)
We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Br?nsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations.
Synthesis of Substituted β-Styrylmalonates by Sequential Isomerization of 2-Arylcyclopropane-1,1-dicarboxylates and (2-Arylethylidene)malonates
Borisov, Denis D.,Chermashentsev, Grigorii R.,Novikov, Roman A.,Tomilov, Yury V.
supporting information, p. 2253 - 2259 (2021/03/04)
A method has been developed for the synthesis of substituted β-styrylmalonates by conversion of 2-arylcyclopropane-1,1-dicarboxylates (ACDCs) in the presence of gallium trichloride into the corresponding- 1,2-zwitterionic intermediates or (2-arylethyl-idene)malonates, followed by treatment with pyridine at room temperature leading to an isomerization of the emerging double bond. This method allows one to expand these reactions to include ACDCs with acceptor substituents at the aromatic ring.
Electricity Driven 1,3-Oxohydroxylation of Donor-Acceptor Cyclopropanes: a Mild and Straightforward Access to β-Hydroxy Ketones
Banerjee, Prabal,Maajid Taily, Irshad,Saha, Debarshi
supporting information, p. 5053 - 5057 (2021/09/30)
An unprecedented external oxidant-free electrochemical protocol for 1, 3-oxohydroxylation of donor-acceptor cyclopropane is disclosed. The strategy encompasses the activation of the labile π-electron cloud of the aryl ring to cleave the strained Csp3?Csp3 bond of cyclopropane to afford the β-hydroxy ketones via insertion of molecular oxygen. More significantly, based on the detailed mechanistic investigations and cyclic voltammetry experiments, a plausible mechanism is proposed.
An Expeditious Route to trans-Configured Tetrahydrothiophenes Enabled by Fe(OTf)3-Catalyzed [3+2] Cycloaddition of Donor–Acceptor Cyclopropanes with Thionoesters
Matsumoto, Yohei,Nakatake, Daiki,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 6062 - 6066 (2018/03/28)
A synthetic route to trans-configured tetrahydrothiophenes (THTs) through Fe(OTf)3-promoted [3+2] cycloaddition of donor–acceptor cyclopropanes with thionoesters was developed. The cycloaddition proceeded in high yield with high diastereoselectivity, affording transient α-alkoxy THTs. Not only aromatic and aliphatic thionoesters, but also thionolactone were applicable to the present iron catalysis. Further transformation of the S,O-ketal functionality of the product was achieved in a highly trans diastereoselective manner. Moreover, the utility of our methodology was clearly demonstrated by the synthesis of enantioenriched trans-configured THTs.
Enantioselective Catalyst Systems from Copper(II) Triflate and BINOL–Silanediol
Guan, Yong,Attard, Jonathan W.,Visco, Michael D.,Fisher, Thomas J.,Mattson, Anita E.
supporting information, p. 7123 - 7127 (2018/05/08)
Silanediol and copper catalysis are merged, for the first time, to create an enhanced Lewis acid catalyst system for enantioselective heterocycle functionalization. The promise of this silanediol and copper catalyst combination is demonstrated in the enantioselective addition of indoles to alkylidene malonates to give rise to the desirable adducts in excellent yield and high enantiomeric excess. From these studies, 1,1′-bi-2-naphthol (BINOL)-based silanediols emerge as one-of-a-kind cocatalysts. Their potential role in the reaction pathway is also discussed.
Intermolecular Reductive Couplings of Arylidene Malonates via Lewis Acid/Photoredox Cooperative Catalysis
McDonald, Benjamin R.,Scheidt, Karl A.
supporting information, p. 6877 - 6881 (2018/11/02)
A cooperative Lewis acid/photocatalytic reduction of arylidene malonates yields a versatile radical anion species. This intermediate preferentially undergoes intermolecular radical-radical coupling reactions, and not the conjugate addition-dimerization reactivity typically observed in the single-electron reduction of conjugate acceptors. Reported here is the development of this open-shell species in intermolecular radical-radical cross couplings, radical dimerizations, and transfer hydrogenations. This reactivity underscores the enabling modularity of cooperative catalysis and demonstrates the utility of stabilized enoate-derived radical anions in intermolecular bond forming reactions.
