Anodic oxidation of organic substrates in the presence of nucleophiles

Abstract

This invention refers to a process of anodic substitution comprising the electrolyzing the liquid reaction medium in an electrochemical cell comprising a cathode and an anode, whereas the liquid reaction medium comprises an organic compound with at least one carbon bound hydrogen atom, a nucleophilic agent, and an ionic liquid in a proportion of at least 10% by weight, and whereas the said hydrogen atoms are replaced at least partially with the nucleophilic group of said nucleophilic agent. Preferably, a gas diffusion layer electrode is used as anode.

1 . A process of anodic substitution, the process comprising:
 b) adding to an electrochemical cell, comprising a cathode and an anode, a liquid reaction medium comprising an organic compound, comprising at least one hydrogen atom bound to a carbon atom, and a nucleophilic agent; and   c) electrolyzing the liquid reaction medium to replace at least some hydrogen atoms of the organic compound with a nucleophilic group of the nucleophilic agent,   wherein the liquid reaction medium further comprises an ionic liquid in a proportion of at least 10% by weight.   
     
     
         2 . The process of  claim 1 , wherein the anode is a gas diffusion layer electrode. 
     
     
         3 . The process of  claim 2 , wherein the gas diffusion layer electrode comprises a substrate and a microporous layer comprising carbon particles as main component. 
     
     
         4 . The process of  claim 2 , wherein the gas diffusion layer electrode comprises a substrate and a microporous layer comprising carbon black as main component. 
     
     
         5 . The process of  claim 1 , wherein the ionic liquid comprises an organic cation comprising an ammonium group. 
     
     
         6 . The process of  claim 1 , wherein the organic compound is selected of the group consisting of
 (i) an alkane or cycloalkane having at least one hydrogen atom directly bound to a tertiary carbon atom,   (ii) an alkene or cycloalkene or diene having at least one hydrogen atom directly bound to an allylic carbon atom,   (iii) an alkyarene having at least one hydrogen atom directly bound to a carbon atom in α-position to the arene moiety,   (iv) an amide having at least one hydrogen atom directly bound to a carbon atom in α-position to the nitrogen atom, and   (v) an ether, ester, carbonate or acetal having at least one hydrogen atom directly bound to a carbon atom in α-position to the oxygen atom.   
     
     
         7 . The process of  claim 1 , wherein the organic compound is a compound of formula (I): 
       
         
           
           
               
               
           
         
         wherein: 
         X is O, N—R 3  or CR 4 R 5 ; 
         R 1  is selected from the group consisting of C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, formyl, C 1 -C 6 -alkylcarbonyl and C 1 -C 6 -alkyloxycarbonyl, with the proviso that:
 if X is a CR 4 R 5  group then R 1  is optionally C 1 -C 6 -alkoxy, and 
 if X is a N—R 3  or CR 4 R 5  group then R 1  is optionally C 1 -C 6 -alkylcarbonyloxy; 
 
         R 2  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, C 6 -C 10 -aryl-C 1 -C 6 -alkyl, C 3 -C 12 -cycloalkyl and C 6 -C 10 -aryl; 
         R 3  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, formyl, C 1 -C 6 -alkylcarbonyl and C 1 -C 6 -alkyloxycarbonyl; 
         R 4  and R 5  are independently selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl and C 1 -C 6 -alkoxy, 
         or R 1  and R 2  together with the X—(C═O)—O group to which they are bound form a 5- to 7-membered heterocyclic ring, which optionally comprises at least one additional heteroatom or heteroatom containing group selected from O, S, NR c  or C═O, wherein R c  is selected from hydrogen, alkyl, cycloalkyl and aryl, 
         or X is a CR 4 R 5  group and R 1  and R 4  together with the carbon atom to which they are bound form a 3 to 7 membered carbocyclic ring. 
       
     
     
         8 . The process of  claim 1 , wherein the organic compound is a compound of formula (Ia): 
       
         
           
           
               
               
           
         
         wherein: 
         X is O, CH 2  or NR 3 ; 
         R 3  is C 1 -C 4 -alkyl or C 1 -C 4 -alkylcarbonyl; 
         A is an alkylene group selected from the group consisting of —CH 2 —, —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —, —CHR 7 —, —CHR 7 —CH 2 —, —CH 2 —CHR 7 —, —CHR 7 —CH 2 —CH 2 —, —CH 2 —CHR 7 —CH 2 —, and —CH 2 —CH 2 —CHR 7 —; 
         R 7  is C 1 -C 6 -alkyl; and 
         R 6  is hydrogen or C 1 -C 6 -alkyl. 
       
     
     
         9 . The process of  claim 1 , wherein the organic compound is a compound of formula (II):
   Z—CHR 8 R 9   (II),
   wherein:   Z is selected from the group consisting of C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, C 1 -C 6 -allyl, —NR 10 R 11  group, and C 1 -C 6 -alkoxy;   R 8  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, and C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, with the proviso that if Z is a C 6 -C 10 -aryl or C 1 -C 6 -allyl then R 8  is optionally C 1 -C 6 -alkoxy,   R 9  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, C 6 -C 10 -aryl-C 1 -C 6 -alkyl, and C 3 -C 12 -cycloalkyl, or   R 8  and R 9  together form a C 4 -C 7 -alkylen or a C 4 -C 7 -alkenylen, and   R 10  and R 11  are independently selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, and C 1 -C 6 -alkylcarbonyl,   or wherein   Z, R 8  and R 9  are independently a C 1 -C 6 -alkyl.   
     
     
         10 . The process of  claim 1 , wherein the nucleophilic agent is selected from a group consisting of water, an alcohol, a carboxylic acid, nitrous acid or salts thereof, nitric acid or salts thereof, hydrozoic acid or salts thereof, isocyanic acid or salts thereof, isothiocyanic acid or salts thereof, sulfonic acid, isoselenocyanic acid or salts thereof, hydrogen cyanide or salts thereof, hydrogen chloride or salts thereof, hydrogen bromide or salts thereof, and hydrogen iodide or salts thereof 
     
     
         11 . The process of  claim 1 , wherein the nucleophilic agent is selected from the group consisting of
 an alcohol of formula (III):
   R 12 OH  (III), and
 
   a carboxylic acid of formula (IV):
   R 13 COOH  (IV),
 
   wherein R 12  and R 13  are C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl.   
     
     
         12 . The process of  claim 1 , wherein the nucleophillic agent does not include fluorinating agents. 
     
     
         13 . The process of  claim 1 , wherein the liquid reaction medium further comprises an additive selected from the group consisting of a bromide salt and an iodide salt. 
     
     
         14 . The process of  claim 1 , wherein the electrochemical cell is an undivided cell. 
     
     
         15 . The process of  claim 1 , wherein the cathode is selected from the group consisting of Pt, Pb, Ni, graphite, a felt material, stainless steel and GDL electrodes. 
     
     
         16 . A process of manufacturing an acetal of the general formula (VI):
   Y—C(OR 12 ) 2 R 14   (VI),
   
       from an organic compound of the general formula (V):
   Y—CH 2 R 14   (V),
 
 wherein: 
 Y is selected from the group consisting of C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, C 1 -C 6 -allyl, and —NR 10 R 11  group; 
 R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; 
 R 14  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, C 6 -C 10 -aryl-C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl and C 3 -C 12 -cycloalkyl; and 
 R 10  and R 11  are independently selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, and C 1 -C 6 -alkylcarbonyl, 
 the process comprising: 
 b) adding to an electrochemical cell, comprising a cathode and an anode, a liquid reaction medium comprising the organic compound of formula (V) and an alcohol of formula (III):
   R 12 OH  (III),
 
 wherein R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; and 
 
 c) electrolyzing the liquid reaction medium to form the acetal of formula (VI) 
 wherein the liquid reaction medium further comprises an ionic liquid in a proportion of at least 10% by weight. 
 
     
     
         17 . A process of manufacturing an aldehyde or ketone of the general formula (VIa):
   Y—COR 14   (VIa),
   
       starting from an organic compound of formula (V):
   Y—CH 2 R 14   (V),
 
 wherein: 
 Y is selected from the group consisting of C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, C 1 -C 6 -allyl, and —NR 10 R 11  group; 
 R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; 
 R 14  is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy-C 1 -C 6 -alkyl, C 6 -C 10 -aryl-C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl and C 3 -C 12 -cycloalkyl; and 
 R 10  and R 11  are independently selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, and C 1 -C 6 -alkylcarbonyl, 
 the process comprising: 
 b) adding to an electrochemical cell, comprising a cathode and an anode, a liquid reaction medium comprising the organic compound of formula (V) and an alcohol of formula (III):
   R 12 OH  (III),
 
 wherein R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; 
 
 c) electrolyzing the liquid reaction medium to form the acetal of formula (VI); and 
 d) hydrolyzing the acetal of formula (VI) to form the aldehyde or ketone of formula (VIa), 
 wherein the liquid reaction medium further comprises an ionic liquid in a proportion of at least 10% by weight. 
 
     
     
         18 . A process of manufacturing an ortho-ester of formula (VIII):
   Y—CR 15   2 (OR 12 )  (VIII),
   
       starting from an organic compound of formula (VII):
   Y—CR 15   2 H  (VII),
 
 wherein: 
 Y is selected from the group consisting of C 6 -C 10 -aryl, substituted C 6 -C 10 -aryl, C 1 -C 6 -allyl, and —NR 10 R 11  group; 
 R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; 
 R 15  is a C 1 -C 12 -alkoxyl; 
 the process comprising: 
 b) adding to an electrochemical cell, comprising a cathode and an anode, a liquid reaction medium comprising the organic compound of formula (VII), a bromide or iodide salt, and an alcohol of formula (III):
   R 12 OH  (III),
 
 wherein R 12  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; and 
 
 c) electrolyzing the liquid reaction medium to form the acetal of formula (VII), 
 wherein the liquid reaction medium further comprises an ionic liquid in a proportion of at least 10% by weight. 
 
     
     
         19 . A process of manufacturing an acyloxylated organic compound of formula (Ib): 
       
         
           
           
               
               
           
         
       
       starting from an organic compound of the formula (Ia): 
       
         
           
           
               
               
           
         
         wherein: 
         X is O, CH 2  or NR 3 ; 
         R 3  is C 1 -C 4 -alkyl or C 1 -C 4 -alkylcarbonyl; 
         A is an alkylene group selected from the group consisting of —CH 2 —, —CH 2 —CH 2   − , —CH 2 —CH 2 —CH 2 —, —CHR 7 —, —CHR 7 —CH 2 —, —CH 2 —CHR 7 —, —CHR 7 —CH 2 —CH 2 —, —CH 2 —CHR 7 —CH 2 —, and —CH 2 —CH 2 —CHR 7 —; 
         R 7  is C 1 -C 6 -alkyl; 
         R 6  is hydrogen or C 1 -C 6 -alkyl; 
         R 13  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl, 
         the process comprising: 
         b) adding to an electrochemical cell, comprising a cathode and an anode, a liquid reaction medium comprising the organic compound of formula (Ia) and an carboxylic acid of formula (IV):
   R 13 COOH  (IV),
 
 wherein R 13  is C 1 -C 12 -alkyl or C 1 -C 12 -perfluorinated alkyl; and 
 
         c) electrolyzing the liquid reaction medium to form the acyloxylated organic compound of formula (Ib), 
         wherein the liquid reaction medium further comprises ionic liquid in a proportion of at least 10% by weight.