Different Substitution Patterns on Triazole

The synthesis of 1//-1,2,3-triazoles has been usually carried out by phenylacety-lene and sodium azide. Other routes to 1//-1,2,3-triazoles include the reaction of sodium azide with nitroalkenes [74] and alkenyl bromides the reaction of ( )-P-arylvinyl bromides and sodium azide [75], which is catalyzed by Pd2(dba)3 and Xantphos the cycloaddition of propargyl cations derived from corresponding alcohols with azides [76]. 

Reports on the preparation of 1-monosubstituted 1,2,3-triazoles are limited one protocol consists of the cycloaddition of azides to acetylene, acetylides, or vinyl compounds aryl boronic acids and prop-2-ynoic acid or CaC2 the decarboxylation of triazoles bearing a carboxylic acid substituent the reaction of aliphatic halides (Cl and Br), sodium azide, and propiolic acid followed by a decarboxylation process [77]. 

The synthesis of 1,4-disubstituted 1,2,3-triazoles is often carried out by a conventional Huisgen cycloaddition between azides and terminal alkynes. 

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