Method for functionalising a double bond

Abstract

The invention concerns a method for functionalizing a double bond and, more particularly, a double bond bearing a metalloid atom. Said functionalization is produced by the action of perhalogenated sulphonyl chloride on the carbon bearing sulphur in the presence of a free radical initiator, preferably by homolytic cleavage. The invention is useful in organic synthesis.

1 . A process for functionalizing a double bond corresponding to formula I:  
       
         
           
           
               
               
           
         
         in which R 1 , R 2  and R 3 , which may be identical or different, are chosen from hydrogen and hydrocarbyls attached to said double bond via an sp 3  carbon;  
         in which z is chosen from: 
 halogens, advantageously chlorine and fluorine;  
 residues such that ZH is an oxygenated acid;  
 radicals of formula (CHR′) m -Ξ with Ξ chosen from halogens;  
 and radicals of formula (CHR′) m —Y(O) q —R 4  in which 
 Y is a chalcogen, advantageously a light chalcogen;  
 q is zero or an integer not more than 3, advantageously not more than 2 and preferably not more than 1, with the condition that when Y is oxygen, q is equal to zero;  
 R′ represents a hydrocarbyl, advantageously of not more than four carbons, or preferably a hydrogen;  
 m is equal to 1 or preferably to zero;  
 and R 4  is chosen from a hydrocarbyl or silyl group;  
 by the action of sulfonyl chloride perhalogenated on the sulfur-bearing carbon (of the sulfonyl function) in the presence of a free-radical initiator, preferably by homolytic cleavage.  
 
 
       
     
     
         2 . The process as claimed in  claim 1 , characterized in that Z is of the nature Y—R 4  with Y being a light chalcogen.  
     
     
         3 . The process as claimed in claims  1  and  2 , characterized in that R 4  is an electron-withdrawing group.  
     
     
         4 . The process as claimed in  claims 1  to  3 , characterized in that the free-radical initiator is an initiator by homolytic cleavage.  
     
     
         5 . A process as claimed in  claims 1  to  4 , characterized in that the perhalogenated sulfonyl chloride corresponds to the formula R f —SO 2 —Cl in which Rf corresponds to the formula:  
       EWG−(CX 2 ) p — in which the radicals X, which may be similar or different, represent a chlorine, a fluorine or a radical of formula C n F 2n+1  with n being an integer not more than 5 and preferably not more than 2, with the condition that at least one of the radicals X is fluorine;    in which p represents an integer not more than 2;    in which EWG represents an electron-withdrawing group, the possible functions of which are inert under the reaction conditions, advantageously fluorine or a perfluoro residue of formula C n F 2n+1 , with n being an integer not more than 8 and advantageously not more than 5, the total number of carbon in R f  advantageously being between 1 and 15 and preferably between 1 and 10.    
     
     
         6 . The process as claimed in  claims 1  to  5 , characterized in that R f  contains not more than 6 carbon atoms, advantageously not more than 5 and preferably not more than 3.  
     
     
         7 . The process as claimed in  claims 1  to  6 , characterized in that Y is oxygen.  
     
     
         8 . The process as claimed in  claims 1  to  7 , characterized in that R 4  is an acyl of not more than 15 carbon atoms and preferably not more than 10 carbon atoms.  
     
     
         9 . A compound of formula (II):  
       
         
           
           
               
               
           
         
       
       with R 1 , R 2 , Z and Rf being chosen from the same values (and with the same preferences) as above, but with the following additional conditions: 
 with R 1  and R 2  chosen from hydrogen and hydrocarbyl radicals, with the condition that one of the radicals R 1  or R 2  at least is equal to H, and advantageously both of them;  
 with Z chosen from radicals of formula (CHR′) m —Y—R 4  in which R 4 Y is such that R 4 YH is an oxygenated acid, the possible aromatic nucleus (nuclei) being separated from said double bond by at least two atoms of sp 3  hybridization (in the case of Z, an oxygen atom and at least one carbon atom, advantageously at least two sp 3  carbon atoms; in the other cases, at least two sp 3  carbon atoms);  
 the total carbon number of the molecule being at least equal to (6−m) and not more than 30. Use of a compound of formula (II) in which m is equal to 1, to prepare a 3-perfluoroalkyl-1,2-epoxypropane:  
 
     
     
         10 . A compound of formula (III)  
       
         
           
           
               
               
           
         
       
     
     
         11 . The use of compounds of formula (III) to prepare a 3-perfluoroalkyl-1,2-epoxypropane.