A Safe and Mild Synthesis of Organic Carbonates from Alkyl Halides and Tetrabutylammonium Alkyl Carbonates
摘要:
A safe and mild procedure for the synthesis of mixed organic carbonates is described. Reaction of commercially available tetrabutylammonium methoxide and ethoxide with carbon dioxide yields the corresponding methyl and ethyl tetrabutylammonium carbonates (TBAMC and TBAEC). The reactions of these new compounds with several different alkyl halides give methyl and ethyl carbonates in high yields. The use of classic toxic and harmful chemicals such as phosgene and carbon monoxide is avoided.
One-pot carbonyl reduction and carbonate formation using sodium borohydride in dialkyl carbonate solvents
作者:Abdulakeem Osumah、Jakob Magolan、Kristopher V. Waynant
DOI:10.1016/j.tetlet.2019.151203
日期:2019.10
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 carbonateformation by treatment with an alkyl chloroformate. 25 examples are presented from 49-92% yield
An easy base-assisted synthesis of unsymmetrical carbonates from alcohols with dimethyl carbonate
作者:Subodh Kumar、Suman L. Jain
DOI:10.1007/s00706-013-1123-3
日期:2014.5
simple and convenient base-mediated synthesis of asymmetrical carbonates from alcohols with dimethyl carbonate is described. The reaction is remarkably influenced by the strength of the base employed and potassiumt-butoxide was found to be best promoter for this reaction. Almost in all cases, the reaction is selective and afforded the corresponding unsymmetrical methyl carbonates in excellent yields
It is challenging to stereoselectively introduce a trifluoromethyl group (CF3) into organic molecules. To date, only limited strategies involving direct asymmetric trifluoromethylation have been reported. Herein, we describe a new strategy for direct asymmetric trifluoromethylation through the copper‐catalyzed stereospecific trifluoromethylation of optically active secondary propargyl sulfonates. The
Non-symmetrical dialkyl carbonate synthesis promoted by 1-(3-trimethoxysilylpropyl)-3-methylimidazolium chloride
作者:Subodh Kumar、Suman L. Jain
DOI:10.1039/c3nj00640a
日期:——
An efficient synthesis of non-symmetrical dialkyl carbonates promoted by 1-(3-trimethoxysilylpropyl)-3-methylimidazolium chloride ionic liquid as a reaction medium is described. The ionic liquid can easily be recovered and reused several times without significant change in the activity and selectivity.
N-Substituted Carbamic Acid Ester Production Method, Isocyanate Production Method Using Such N-Substituted Carbamic Acid Ester, And Composition For Transfer And Storage Of N-Substituted Carbamic Acid Ester Comprising N-Substituted Carbamic Acid Ester and Aromatic Hydroxy Compound
申请人:Shinohata Masaaki
公开号:US20110133121A1
公开(公告)日:2011-06-09
The present invention is a method for producing an N-substituted carbamic acid ester derived from an organic amine from an organic amine, a carbonic acid derivative and a hydroxy composition containing one or more types of hydroxy compounds, wherein the organic amine, the carbonic acid derivative and the hydroxy composition are reacted using a urethane production reaction vessel provided with a condenser, a gas containing the hydroxy composition, the compound having the carbonyl group derived from the carbonic acid derivative, and an ammonia formed as a by-product in the reaction, is introduced into the condenser provided in the urethane production reaction vessel, and the hydroxy composition and the compound having the carbonyl group derived from the carbonic acid derivative are condensed, and wherein a stoichiometric ratio of a hydroxy compound contained in the condensed hydroxy composition to the condensed compound having the carbonyl group derived from the carbonic acid derivative is 1 or more, and a ratio of number of carbonyl groups (—C(═O)—) contained in the compound having the carbonyl group derived from the carbonic acid derivative and number of ammonia molecules contained in the ammonia recovered as a gas from the condenser is 1 or less.