Novel methods for preparation of substituted pyridines and related novel compounds

Abstract

The present invention relates to novel methods of preparation of substituted pyridines and the compounds produced therefrom. In particular, the present invention provides efficient methods for the construction of diversely substituted pyridines, with varying substitution patterns under simple and metal-free conditions with high atom- and pot-economy and excellent functional group tolerance, and which are useful for the synthesis of natural products.

What is claimed is: 
     
         1 . A compound of formula (I) 
       
         
           
           
               
               
           
         
         wherein
 R 1  is selected from the group consisting of H, (C 1 -C 4 )alkyl, (C 2 -C 10 )alkenyl, indolylalkyl, aryl, and heteroaryl, each of which may be optionally substituted with 1 to 5 substituents selected from the group consisting of (C 1 -C 4 )haloalkyl, (C 1 -C 4 )alkoxy, —CN, halogen, NO 2 , (C 1 -C 4 )alkyl and OH; 
 R 2  is selected from the group consisting of H and (C 1 -C 4 )alkyl; 
 
         or R 1  and R 2  may be taken together with the carbons to which they are attached to form a ring structure selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl, each of which may be optionally substituted with 1 to 3 substituents selected from the group consisting of (C 1 -C 4 )haloalkyl, (C 1 -C 4 )alkoxy, —CN, halogen, NO 2 , (C 1 -C 4 )alkyl, (C 2 -C 4 )alkenyl, and OH;
 R 3  is selected from the group consisting of H, (C 1 -C 4 )alkyl, (C 1 -C 6 )alkylcarbonyl, and benzyl; 
 R 4  is selected from the group consisting of H, —CH 2 , (C 1 -C 10 )alkyl, (C 2 -C 10 )alkenyl, indolylalkyl, aryl, and heteroaryl each of which is optionally substituted with 1 to 4 substituents selected from the group consisting of (C 1 -C 4 )alkyl, (C 1 -C 4 )haloalkyl, (C 1 -C 4 )alkoxy, halogen, —CN, NO 2 , —C(O)O—(C 1 -C 4 )alkyl, —C(O)(C 1 -C 4 )alkyl, —O—(C 1 -C 4 )alkyl, and OH; and 
 X is N and Y is CR 5 , wherein R 5  is H or (C 1 -C 4 )alkyl, 
 
         with the proviso that the compound of formula (I) is not: 
       
       
         
           
           
               
               
           
         
       
     
     
         2 . The compound of  claim 1  selected from a compound of formula (IV): 
       
         
           
           
               
               
           
         
       
     
     
         3 . The compound of  claim 1  selected from a compound of formula (V): 
       
         
           
           
               
               
           
         
         wherein
 Z is selected from the group consisting of —O—, —S—, —N(R 6 )—, wherein R 6  is H, (C 1 -C 4 )alkyl, tosyl, benzyl, phenyl, tert-butyloxycarbonyl. 
 
       
     
     
         4 . The compound of  claim 1  selected from a compound of formula (VI) 
       
         
           
           
               
               
           
         
         wherein
 Z is selected from the group consisting of —O—, —S—, —N(R 6 )—, wherein R 6  is H, (C 1 -C 4 )alkyl, tosyl, benzyl, phenyl, tert-butyloxycarbonyl; and 
 R 7  and R 8  are each independently selected from the group consisting of H, (C 1 -C 4 )haloalkyl, (C 1 -C 4 )alkoxy, —CN, halogen, NO 2 , (C 1 -C 4 )alkyl, (C 2 -C 4 )alkenyl, and OH. 
 
       
     
     
         5 . A compound selected from the following: