- Highly efficient synthesis of cyclic ureas from CO2 and diamines by a pure CeO2 catalyst using a 2-propanol solvent
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Pure cerium oxide (CeO2) acts as an effective and reusable heterogeneous catalyst for direct synthesis of cyclic ureas from CO2 and diamines even at a low CO2 pressure of 0.3 MPa. 2-Propanol is the most preferable solvent to provide good selectivity. The system composed of a CeO2 catalyst and a 2-propanol solvent is applied to various diamines to provide the corresponding cyclic ureas in high yields (78-98%), including six-membered-ring ureas that are difficult to be synthesized from CO 2. Based on the kinetic studies on the effect of CO2 pressure and amine concentration and FTIR studies on adsorption of ethylenediamine and CO2 onto CeO2, the following mechanism for the synthesis of cyclic urea is proposed: (1) formation of carbamic acid and carbamate species on CeO2, (2) decomposition of carbamic acid to a free amino group and CO2, (3) nucleophilic attack of the amino group on the carbamate on CeO2 to produce the cyclic urea and (4) desorption of the product and regeneration of CeO2.
- Tamura, Masazumi,Noro, Kensuke,Honda, Masayoshi,Nakagawa, Yoshinao,Tomishige, Keiichi
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- Catalytic oxidative carbonylation of primary and secondary α,ω-diamines to cyclic ureas
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(matrix presented) Primary and secondary diamines can be catalytically carbonylated to cyclic ureas using W(CO)6 as the catalyst, I2 as the oxidant, and CO as the carbonyl source. Preparation of five-, six-, and seven-membered cyclic ureas from the diamines RNHCH2(CH2)nCH2NHR (n = 0-2; R = H, Me) and RNHCH2CH2NHR (R = Et, i-Pr, Bz) was achieved in moderate to good yields.
- McCusker, Jennifer E.,Grasso, Cara A.,Main, Andrea D.,McEiwee-White, Lisa
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- Total synthesis of (±)-manzacidin D
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We report herein the first total synthesis of the alkaloid manzacidin D, in 11 steps and 16% overall yield from commercially available glycine tert-butyl ester hydrochloride. Our synthesis demonstrates for the first time in a total synthesis the utility of two different methodologies. A highly diastereoselective iodocyclization of an olefinic isothiourea is used to induce stereocontrol at the quaternary centre, and to form the heterocyclic core. Conversion of a thiourea to the requisite formamidine is achieved in good yield using our modified procedure.
- Drouin, Christian,Woo, Jacqueline C.S.,MacKay, D. Bruce,Lavigne, Roch M.A.
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- PROCESS FOR THE PRODUCTION OF CYCLIC GUANIDINE DERIVATES
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The present invention relates to a process for the production of cyclic guanidine derivates of formula I or mixtures of them (formula I) by reacting a triamine in the present of a C1-source and a solid material in the gas or liquid phase under inert atmosphere.
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Page/Page column 10-11
(2021/04/30)
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- Alkylamine-Substituted Perthiocarbamates: Dual Precursors to Hydropersulfide and Carbonyl Sulfide with Cardioprotective Actions
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The recent discovery of hydropersulfides (RSSH) in mammalian systems suggests their potential roles in cell signaling. However, the exploration of RSSH biological significance is challenging due to their instability under physiological conditions. Herein, we report the preparation, RSSH-releasing properties, and cytoprotective nature of alkylamine-substituted perthiocarbamates. Triggered by a base-sensitive, self-immolative moiety, these precursors show efficient RSSH release and also demonstrate the ability to generate carbonyl sulfide (COS) in the presence of thiols. Using this dually reactive alkylamine-substituted perthiocarbamate platform, the generation of both RSSH and COS is tunable with respect to half-life, pH, and availability of thiols. Importantly, these precursors exhibit cytoprotective effects against hydrogen peroxide-mediated toxicity in H9c2 cells and cardioprotective effects against myocardial ischemic/reperfusion injury, indicating their potential application as new RSSH- and/or COS-releasing therapeutics.
- Khodade, Vinayak S.,Pharoah, Blaze M.,Paolocci, Nazareno,Toscano, John P.
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supporting information
p. 4309 - 4316
(2020/03/05)
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- 3-(Triflyloxy)benzynes Enable the Regiocontrolled Cycloaddition of Cyclic Ureas to Synthesize 1,4-Benzodiazepine Derivatives
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A versatile synthesis of 1,4-benzodiazepine derivatives through the reaction of various 3-(trifluoromethanesulfonyloxy)benzynes with N -(p -toluenesulfonyl)imidazolidin-2-ones is reported. This reaction system provides a 1,4-benzodiazepine bearing a trifluoromethanesulfonyloxy group as a single regioisomer among the four possible regioisomers.
- Kaneko, Hideki,Ikawa, Takashi,Yamamoto, Yuta,Arulmozhiraja, Sundaram,Tokiwa, Hiroaki,Akai, Shuji
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supporting information
p. 943 - 948
(2018/02/26)
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- ORTHO-SUBSTITUTED HALOALKYLSULFONANILIDE DERIVATIVE AND HERBICIDE
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Novel herbicides are provided. A haloalkylsulfonanilide derivative represented by the formula (1) or an agrochemically acceptable salt thereof: the formula (1): wherein A is -C(R7)(R8)- or -N(R9)-, W is an oxygen atom or a sulfur atom, n is an integer of from 1 to 4, R1 is halo C1 -C6 alkyl, R2 is a hydrogen atom, C1 - C6 alkyl or the like, each of R3 and R4 is independently a hydrogen atom, C1 - C6 alkyl or the like, each of R5, R6, R7 and R8 is independently a hydrogen atom, a halogen, C1 - C6 alkyl or the like, R9 is a hydrogen atom, C1 - C6 alkyl or the like, and X is halogen, C1 - C6 alkyl or the like.
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Page/Page column 126
(2011/07/06)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- HYDROXYMETHYL PYRROLIDINES AS BETA 3 ADRENERGIC RECEPTOR AGONISTS
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The present invention provides compounds of Formula I, pharmaceutical compositions thereof, and method of using the same in the treatment or prevention of diseases mediated by the activation of β3-adrenoceptor.
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Page/Page column 63-64
(2009/10/30)
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- Cyclic Urea and Thiourea Derivatives as Inducers of Murine Erythroleukemia Differentiation
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A series of derivatives of tetramethylurea, a known inducer of the differentiation of Friend erythroleukemia cells, has been synthesized and tested for its capacity to induce erythroid maturation, as measured by the synthesis of hemoglobin.Cyclic urea and thiourea derivatives consisting of five-, six-, and seven-membered ring systems containing N-alkyl substituents were prepared.Most of these agents were relatively effective inducers of differentiation, with N-alkyl substitution appearing to be essential for maximum response.The most potent agents developed wereN,N'-dimethyl cyclic ureas.Exposure to concentrations of 2 to 4 mM of these derivatives resulted in more than 90percent of the cell population achieving a differentiated state.Under these conditions, the parent compound, tetramethylurea, was slightly less efficacious, causing differentiation of only 68percent of the population at its maximum effective level of 4 mM.
- Li, Chau-der,Mella, Sharon L.,Sartorelli, Alan C.
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p. 1089 - 1092
(2007/10/02)
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