2050-95-5Relevant academic research and scientific papers
Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
Jahn, Ullrich,Ma?ek, Tomá?
, p. 11608 - 11632 (2021/09/02)
The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
Method for Preparing Carbonic Ester Using Organometallic Compound
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Page/Page column 4-5, (2015/11/27)
A method for preparing a carbonic ester includes reacting carbon dioxide and a C1 to C10 alcohol with an organometallic compound represented by Formula 1. With the method, carbonic ester can be prepared in high yield without recycling the organometallic compound. [in-line-formulae]M(OR1)4 ??[Formula 1][/in-line-formulae]wherein M is a Group IV or Group XIV element and each R1 is independently a C1 to C10 hydrocarbon group.
Mixture for recovery utilization or transfer of carbon dioxide
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, (2013/03/26)
It is an object of the present invention to provide a mixture for recovery utilization or transfer of carbon dioxide gas. According to the present invention, disclosed is a mixture containing carbon dioxide and an alkyltin alkoxide composition containing carbon dioxide complex of an alkyltin alkoxide, the mixture having a composition with a specified ratio.
PROCESS FOR PRODUCING ISOCYANATE
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Page/Page column 39-40, (2011/02/18)
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a thermal decomposition reaction, including the steps of: recovering a low boiling point component in a form of a gaseous phase component from a thermal decomposition reaction vessel in which the thermal decomposition reaction is carried out; recovering a liquid phase component containing a carbamic acid ester from a bottom of the thermal decomposition reaction vessel; and supplying all or a portion of the liquid phase component to an upper portion of the thermal decomposition reaction vessel.
ISOCYANATE PRODUCTION PROCESS
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Page/Page column 32, (2011/05/03)
An object of the present invention is to provide a process that enables isocyanate to be produced stably over a long period of time and at high yield without encountering problems of the prior art during production of isocyanate without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a thermal decomposition reaction, including the steps of: recovering a low boiling point component in a form of a gaseous phase component from a thermal decomposition reaction vessel in which the thermal decomposition reaction is carried out; recovering a liquid phase component containing a carbamic acid ester from a bottom of the thermal decomposition reaction vessel; and supplying all or a portion of the liquid phase component to an upper portion of the thermal decomposition reaction vessel.
PROCESS FOR PRODUCTION OF ALKYL TIN ALKOXIDE COMPOUND, AND PROCESS FOR PRODUCTION OF CARBONATE ESTER USING THE COMPOUND
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Page/Page column 75, (2010/09/17)
The present invention provides a process for producing : a compound represented by XOR2; a dialkyl tin dialkoxide compound having one tin atom, two Sn-R1 bonds and two Sn-OR2 bonds; and/or a tetraalkyl dialkoxy distannoxane compound having one Sn-O-Sn bond, in which each tin atom of the tetraalkyl dialkoxy distannoxane compound has two Sn-R1 bonds and one Sn-OR2 bond, the process comprising reacting in the absence of a catalyst at least one alkyl tin compound selected from the group consisting of i) and ii) below: i) a dialkyl tin compound having one tin atom, two Sn-R1 (wherein R1 represents an alkyl group) bonds, and two Sn-OX bonds (wherein OX is a group in which HOX that is a conjugate acid of OX is a Bronsted acid having a pKa of from 0 to 6.8); and ii) a tetraalkyl distannoxane compound having one Sn-O-Sn bond, in which each tin atom of the tetraalkyl distannoxane compound has two Sn-R1 bonds and one Sn-OX bond (wherein OX is a group in which HOX that is a conjugate acid of OX is a Bronsted acid having a pKa of from 0 to 6.8); and a carbonic acid ester represented by R2OCOOR2 (wherein R2 represents a linear or branched, saturated or unsaturated hydrocarbon group, a hydrocarbon group having a saturated or unsaturated cyclic hydrocarbon substituent, or a Y-CH2- group (wherein Y represents an alkyl polyalkylene group, an aromatic group or a cyclic saturated or unsaturated alkylene ether group)), and/or an alcohol represented by R2OH (wherein R2 is the same as defined above).
Method for Separating Out and Recovering Dialkyltin Dialkoxide
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Page/Page column 28, (2010/07/04)
For an alkyltin alkoxide catalyst composition used in carbonate production, there is a problem that the alkyltin alkoxide catalyst composition is thermally decomposed by being heated in the production process, changing into an undistillable alkyltin alkoxide catalyst composition containing a high boiling deactivated component and an active component. The present invention provides a method for separating out and recovering the active component from the alkyltin alkoxide catalyst composition as a useful dialkyltin dialkoxide. According to the present invention, there is disclosed a method in which such an undistillable alkyltin alkoxide catalyst composition containing a high boiling deactivated component and an active component is reacted with an alcohol and/or a carbonate, so as to obtain a reaction liquid containing a product originating from the active component, and then the reaction liquid is subjected to distillation, so as to separate out and recover a dialkyltin dialkoxide from the product originating from the active component.
Process for Production of Alkyl Tin Alkoxide Compound, and Process for Production of Carbonic Acid Ester Using the Compound
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Page/Page column 56, (2010/12/18)
The present invention provides a process for producing: a compound represented by XOR2; a dialkyl tin dialkoxide compound having one tin atom, two Sn—R1 bonds and two Sn—OR2 bonds; and/or a tetraalkyl dialkoxy distannoxane compound having one Sn—O—Sn bond, in which each tin atom of the tetraalkyl dialkoxy distannoxane compound has two Sn—R1 bonds and one Sn—OR2 bond, the process comprising reacting in the absence of a catalyst at least one alkyl tin compound selected from the group consisting of i) and ii) below: i) a dialkyl tin compound having one tin atom, two Sn—R1 (wherein R1 represents an alkyl group) bonds, and two Sn—OX bonds (wherein OX is a group in which HOX that is a conjugate acid of OX is a Bronsted acid having a pKa of from 0 to 6.8); andii) a tetraalkyl distannoxane compound having one Sn—O—Sn bond, in which each tin atom of the tetraalkyl distannoxane compound has two Sn—R1 bonds and one Sn—OX bond (wherein OX is a group in which HOX that is a conjugate acid of OX is a Bronsted acid having a pKa of from 0 to 6.8); anda carbonic acid ester represented by R2OCOOR2 (wherein R2 represents a linear or branched, saturated or unsaturated hydrocarbon group, a hydrocarbon group having a saturated or unsaturated cyclic hydrocarbon substituent, or a Y—CH2— group (wherein Y represents an alkyl polyalkylene group, an aromatic group or a cyclic saturated or unsaturated alkylene ether group)), and/oran alcohol represented by R2OH (wherein R2 is the same as defined above).
METHOD FOR PRODUCTION OF ISOCYANATE USING COMPOSITION COMPRISING CARBAMIC ACID ESTER AND AROMATIC HYDROXY COMPOUND, AND COMPOSITION FOR TRANSPORT OR STORAGE OF CARBAMIC ACID ESTER
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Page/Page column 48-49, (2010/02/17)
An object of the present invention is to provide an isocyanate production process, which is free of the various problems found in the prior art, and which uses a composition containing a carbamic acid ester and an aromatic hydroxy compound when producing isocyanate without using phosgene, as well as a carbamic acid ester composition for transferring or storing carbamic acid ester. The present invention discloses an isocyanate production process including specific steps and using a composition containing a carbamic acid ester and an aromatic hydroxy compound, as well as a composition for transfer or storage of carbamic acid ester comprising the carbamic acid ester and the specific aromatic hydroxy compound.
METHOD FOR PRODUCING ISOCYANATE
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Page/Page column 26, (2009/09/05)
An object of the present invention is to provide a process that enables isocyanates to be stably produced over a long period of time at high yield without encountering various problems as found in the prior art when producing isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate, comprising the steps of: reacting a carbamic acid ester and an aromatic hydroxy compound to obtain an aryl carbamate having a group derived from the aromatic hydroxy compound; and subjecting the aryl carbamate to a decomposition reaction, wherein the aromatic hydroxy compound is an aromatic hydroxy compound which is represented by the following formula (1) and which has a substituent R1 at at least one ortho position of a hydroxyl group: (wherein ring A represents an aromatic hydrocarbon ring in a form of a single or multiple rings which may have a substitute and which have 6 to 20 carbon atoms; R1 represents a group other than a hydrogen atom in a form of an aliphatic alkyl group having 1 to 20 carbon atoms, an aliphatic alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an aralkyloxy group having 7 to 20 carbon atoms, the group containing an atom selected from a carbon atom, an oxygen atom and a nitrogen atom; and R1 may bond with A to form a ring structure).
