15177-62-5

A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.

A protocol for the hydrocarboxylation of disubstituted alkenes and terminal alkynes providing access to different secondary carboxylic acids and malonic acid derivatives has been developed. This methodology relies on an initial hydroboration using 9-BBN followed by carboxylation with carbon dioxide in the presence of a copper catalyst and the additive, cesium fluoride. Different cyclohexene, styrene, and stilbene derivatives could be utilized, and alkynes could be transformed into their corresponding dicarboxylic acids in good yields. Finally, six different terpenoids were carboxylated using the developed procedure. (Chemical Equation Presented).

The present invention relates to a new method for obtaining a purity of about 93% to 100% of the trans form of 2- or 4-substituted cyclohexanecarboxylic acid or reactive derivatives thereof from the cis form or a mixture of the cis and trans forms by a single step, particularly, to a method for obtaining a purity of substantially 100% of the trans form of 4-substituted cyclohexanecarboxylic acid.

The reactions of cycloalkanes with CO via the C-H bond activation by Pd(OAc)2 catalyst have been found to proceed regio- and stereo-selectively to give corresponding carboxylic acids.The reactivity of C-H bonds of cycloalkanes decreases in the order: tert- > sec- > prim-carbon, and the stereochemistry of the substitutents on the main products is all equatorial.

The electrochemical reaction of phenylacetylene with trialkylboranes in a tetrahydrofuran solution containing tetraalkylammonium halide gives the corresponding alkynes via a retention of configuration with respect to the boron-carbon bonds.The reaction mechanism is also discussed.

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