22768-02-1Relevant articles and documents
Organotin-oxomolybdate coordination polymer as catalyst for synthesis of unsymmetrical organic carbonates
Song, Jinliang,Zhang, Binbin,Wu, Tainbin,Yang, Guanying,Han, Buxing
, p. 922 - 927 (2011)
Efficient and greener synthesis of unsymmetrical organic carbonates is of great importance. In this work, two organotin-oxometalates, Bu 2SnMoO4 and (Bu3Sn)2MoO4, were prepared and their catalytic performance for the transesterification of diethyl carbonate (DEC) with alcohols to synthesize unsymmetrical organic carbonates was studied. It was found that (Bu3Sn)2MoO 4 was very active and selective for the transesterification of DEC and various alcohols, including alkyl, cyclic, and aryl alcohols due to the synergetic effect between the groups of [MoO4]2- and [Bu3Sn]+ in the catalyst. The yields of the corresponding carbonates could reach 98% at the suitable conditions. The catalyst was reused five times and the activity and selectivity were not changed. We believe that the highly efficient, versatile, greener, inexpensive, selective and stable catalyst has great potential applications in the synthesis of various unsymmetrical organic carbonates from DEC and alcohols. The Royal Society of Chemistry.
N-Heterocyclic Carbene-Phosphinidene Complexes of the Coinage Metals
Doddi, Adinarayana,Bockfeld, Dirk,Nasr, Alexandre,Bannenberg, Thomas,Jones, Peter G.,Tamm, Matthias
, p. 16178 - 16189 (2015)
Coinage metal complexes of the N-heterocyclic carbene-phosphinidene adduct IPr·PPh (IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were prepared by its reaction with CuCl, AgCl, and [(Me2S)AuCl], which afforded the monometallic complexes [(IPr·PPh)MCl] (M=Cu, Ag, Au). The reaction with two equivalents of the metal halides gave bimetallic [(IPr·PPh)(MCl)2] (M=Cu, Au); the corresponding disilver complex could not be isolated. [(IPr·PPh)(CuOTf)2] was prepared by reaction with copper(I) trifluoromethanesulfonate. Treatment of [(IPr·PPh)(MCl)2] (M=Cu, Au) with Na(BArF) or AgSbF6 afforded the tetranuclear complexes [(IPr·PPh)2M4Cl2]X2 (X=BArF or SbF6), which contain unusual eight-membered M4Cl2P2 rings with short cuprophilic or aurophilic contacts along the chlorine-bridged M...M axes. Complete chloride abstraction from [(IPr·PPh)(AuCl)2] was achieved with two equivalents of AgSbF6 in the presence of tetrahydrothiophene (THT) to form [(IPr·PPh){Au(THT)}2][SbF6]2. The cationic tetra- and dinuclear complexes were used as catalysts for enyne cyclization and carbene transfer reactions.
The synthesis of organic carbonates over nanocrystalline CaO prepared via microemulsion technique
Adam, Farook,Wong, Min-Siang
, p. 87 - 90 (2011)
A new method, combining microemulsion, ultrasonication and ultracentrifugation with the addition of polyethylene glycol was developed to synthesize nanocrystalline CaCO3. Calcination of the CaCO3 resulted in nanocrystalline CaO. Physical characterization by XRD indicated that the material had high purity of nanocrystalline CaCO3 and CaO particles respectively. TEM images showed that the material was composed of non-agglomerated, single nanoparticles with a size range of 10-30 nm. The CaO was used as a catalyst in the solvent free direct condensation of diethyl carbonate with benzyl alcohol. The catalytic reaction resulted in 99.7% conversion and 100% selectivity for benzyl ethyl carbonate in 3 h.
One-pot carbonyl reduction and carbonate formation using sodium borohydride in dialkyl carbonate solvents
Osumah, Abdulakeem,Magolan, Jakob,Waynant, Kristopher V.
supporting information, (2019/10/14)
Preparation of mixed carbonates proceeded in one step from ketones and aldehydes via treatment with NaBH4 in dimethyl or diethyl carbonate solvent at elevated temperatures. This is an efficient and convenient alternative to the traditional two-step sequence of carbonyl reduction to alcohol and subsequent carbonate formation by treatment with an alkyl chloroformate. 25 examples are presented from 49 to 92% yield, highlighting the versatility of this reaction.
Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
Mevan Dissanayake,Melville, Alex D.,Vannucci, Aaron K.
supporting information, p. 3165 - 3171 (2019/06/18)
An electrosynthesis method for amide bond formation has been developed in an attempt to increase the atom economy for this class of reactions. This "anion pool" method electrochemically generates strong nucleophiles from amine substrates. The amine nucleophiles then react with acid anhydrides to generate amides, and the by-product from this reaction undergoes further chemical transformations to generate pharmaceutically relevant benzoic esters. These one-pot reactions are operationally simple, are performed at room temperature, and avoid rare transition metals and added bases. The amide synthesis is amenable to primary and secondary amines and a variety of anhydrides with yields up to 90% obtained. Atom economy and process mass index (PMI) values calculated for this procedure indicate that this process can be considered greener compared to traditional amide synthesis routes used by industry. Furthermore, this electrochemical approach showed unique selectivity when substrates that contained two inequivalent amine moieties were examined.
Carbon Dioxide Utilisation for the Synthesis of Unsymmetrical Dialkyl and Cyclic Carbonates Promoted by Basic Ionic Liquids
Goodrich, Peter,Gunaratne, H. Q. Nimal,Jin, Lili,Lei, Yuntao,Seddon, Kenneth R.
, p. 181 - 185 (2018/03/09)
An efficient and greener synthesis of unsymmetrical organic carbonates mediated by Hünig's base-appended basic ionic liquids, via carbon dioxide conversion, is described here. These ionic liquids were found to be effective bases for the fixation of carbon dioxide by various alcohols and benzyl bromide, at room temperature. When the alcohol and the halide functionalities are present within the same substrate, the reaction cleanly produces a cyclic carbonate. These functionalised basic ionic liquids were fully recyclable with no loss product yields.
Immobilization of 1,5,7-triazabicyclo[4.4.0]dec-5-ene on magnetic γ-Fe2O3 nanoparticles: A highly recyclable and efficient nanocatalyst for the synthesis of organic carbonates
Wu, Liqiang,Tian, Shuanbao
, p. 2080 - 2087 (2015/04/27)
1,5,7-Triazabicyclo[4.4.0]dec-5-ene was immobilized on magnetic γ-Fe2O3 nanoparticles as a magnetic nanocatalyst. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient and selective synthesis of organic carbonates by the direct condensation of alcohols and diethyl carbonate. The catalyst is quantitatively recovered by an external magnet and can be reused for six cycles with almost consistent activity. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene was immobilized on magnetic γ-Fe2O3 nanoparticles as a magnetic nanocatalyst. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient and selective synthesis of organic carbonates by the direct condensation of alcohols and diethyl carbonate.
Immobilization of 1,5,7-triazabicyclo[4.4.0]dec-5-ene on magnetic γ-Fe2O3 nanoparticles: A highly recyclable and efficient nanocatalyst for the synthesis of organic carbonates
Wu, Liqiang,Tian, Shuanbao
, p. 2080 - 2087 (2014/05/06)
1,5,7-Triazabicyclo[4.4.0]dec-5-ene was immobilized on magnetic γ-Fe2O3 nanoparticles as a magnetic nanocatalyst. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient and selective synthesis of organic carbonates by the direct condensation of alcohols and diethyl carbonate. The catalyst is quantitatively recovered by an external magnet and can be reused for six cycles with almost consistent activity. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene was immobilized on magnetic γ-Fe2O3 nanoparticles as a magnetic nanocatalyst. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient and selective synthesis of organic carbonates by the direct condensation of alcohols and diethyl carbonate. Copyright
β-aryl nitrile construction via palladium-catalyzed decarboxylative benzylation of α-cyano aliphatic carboxylate salts
Shang, Rui,Huang, Zheng,Xiao, Xiao,Lu, Xi,Fu, Yao,Liu, Lei
supporting information, p. 2465 - 2472,8 (2020/08/31)
The palladium-catalyzed decarboxylative benzylation of α-cyano aliphatic carboxylate salts with benzyl electrophiles was discovered. This reaction exhibits good functional group compatibility and proceeds under relatively mild conditions. A diverse range of quaternary, tertiary and secondary β-aryl nitriles can be conveniently prepared by this method. Copyright
Alkali-metal ion catalysis in alkaline ethanolysis of 2-pyridyl benzoate and benzyl 2-pyridyl carbonate: Effect of modification of nonleaving group from benzoyl to benzyloxycarbonyl
Um, Ik-Hwan,Kang, Ji-Sun,Kim, Chae Won,Lee, Jae-In
, p. 519 - 523 (2012/05/04)
A kinetic study is reported on nucleophilic displacement reactions of benzyl 2-pyridyl carbonate 6 with alkalimetal ethoxides, EtOM (M = Li, Na, and K), in anhydrous ethanol at 25.0 ± 0.1 oC. The plots of pseudo-firstorder rate constant kobsd vs. [EtOM] curve upward, a typical phenomenon reported previously for alkaline ethanolysis of esters in which alkali-metal ions behave as a Lewis-acid catalyst. The kobsd value for the reaction of 6 with a fixed EtOK concentration decreases rapidly upon addition of 18-crown-6-ether (18C6), a complexing agent for K+ ion up to [18C6]/[EtOK] = 1.0 and then remains constant thereafter, indicating that the catalytic effect exerted by K+ ion disappears in the presence of excess 18C6. The reactivity of EtOM towards 6 increases in the order EtO- EtOLi EtONa EtOK, which is contrasting to the reactivity order reported for the corresponding reactions of 2-pyridyl benzoate 4, i.e., EtO- EtOK EtONa EtOLi. Besides, 6 is 1.7 and 3.5 times more reactive than 4 towards dissociated EtO- and ion-paired EtOK, respectively. The reactivity difference and the contrasting metal-ion selectivity are discussed in terms of electronic effects and transition-state structures.
