Preparation of organic compounds bearing a trifluoromethyl group on a quaternary carbon
A method for preparing a molecule bearing a trifluoromethyl group on a quaternary carbon atom, includes providing a reactant having a quaternary carbon atom bearing a carboxylic acid group and an electron withdrawing group; and reacting the reactant with SF 4 in a solvent to substitute the carboxylic acid group with the trifluoromethyl group and provide a reaction product mixture including the molecule bearing the trifluoromethyl group on the quaternary carbon atom.
1 . A method for preparing a molecule bearing a trifluoromethyl group on a quaternary carbon atom, said method comprising:
providing a reactant comprising a quaternary carbon atom bearing a carboxylic acid group and an electron withdrawing group; and
reacting the reactant with SF 4 in a solvent to substitute the carboxylic acid group with the trifluoromethyl group and provide a reaction product mixture comprising the molecule bearing the trifluoromethyl group on the quaternary carbon atom.
2 . The method of claim 1 , wherein the electron withdrawing group is an ester.
3 . The method of claim 1 , wherein the solvent comprises at least one member selected from the group consisting of HF, ethers, THF, hydrocarbons and fluorocarbons.
4 . The method of claim 1 , wherein the solvent comprises HF.
5 . The method of claim 1 , wherein the reactant is represented by a formula selected from the following group:
where R′ is C 1 -C 10 alkyl and R″ is C 1 -C 5 alkyl.
6 . The method of claim 1 , further comprising purifying the molecule from the reaction product mixture by at least one of recrystallization, distillation and chromatography.
7 . The method of claim 1 , wherein subsequent to the reacting step, the electron withdrawing group is converted to another group selected from the group consisting of aldehyde, alcohol, acid chloride and olefin.
8 . The method of claim 7 , wherein the electron withdrawing group is an ester and the ester is converted to an aldehyde which is further converted to an alcohol.
9 . The method of claim 7 , wherein the electron withdrawing group is an ester and the ester is converted to an acid which is converted to an acid chloride, the acid chloride is converted to a ketone.
10 . A method for preparing a molecule bearing a trifluoromethyl group and an alkyl group on a quaternary carbon atom, said method comprising the sequential steps of:
providing a reactant comprising a quaternary carbon atom bearing a carboxylic acid group and an ester group;
reacting the reactant with SF 4 in a solvent to substitute the carboxylic acid group with the trifluoromethyl group; and substituting the alkyl group for the ester group to provide the molecule bearing the trifluoromethyl group and the alkyl group on the quaternary carbon atom
11 . The method of claim 10 , wherein the solvent comprises at least one member selected from the group consisting of HF, ethers, THF, hydrocarbons and fluorocarbons.
12 . The method of claim 10 , wherein the solvent comprises HF.
13 . The method of claim 10 , wherein the substituting step comprises converting the ester to an aldehyde, converting the aldehyde to a vinyl-substituted or alcohol-substituted intermediate, and hydrogenating the intermediate.
14 . The method of claim 10 , wherein the substituting step comprises converting the ester to an acid, converting the acid to an acid chloride, reacting the acid chloride with an organometallic reagent to form a ketone, and reducing the carbonyl group of the ketone to a methylene group.
15 . A method for preparing a molecule bearing a trifluoromethyl group on a quaternary carbon atom, said method represented by the following equation:
where:
(i) R 1 is an electron withdrawing group selected from the group consisting of: (a) carboxylic acid esters, COOR′, where R′ is unsubstituted alkyl, substituted alkyl, unsubstituted aryl, or substituted aryl of 1-20 carbon atoms; (b) NO 2 ; (c) SOR, where R is alkyl or aryl; (d) SO 2 R, where R is alkyl or aryl; (e) POOR 3 , where R is alkyl or aryl; (f) PR 3 , where R is alkyl or aryl; and (g) CN, and
(ii) R 3 , R 4 is cycloalkyl of 3-8 carbon atoms, or
(iii) R 3 and R 4 are independently selected from the group consisting of unsubstituted alkyl, substituted alkyl, unsubstituted aryl, and substituted aryl of 1-20 carbon atoms.
16 . The method of claim 15 , wherein the solvent comprises at least one member selected from the group consisting of HF, ethers, THF, hydrocarbons and fluorocarbons.
17 . The method of claim 15 , wherein the solvent comprises HF.