Phosphonation Of Indoles And N-sulfonylation Of Benzimidazoles

In recent years,the construction of C(sp~2)-P bonds by C-H activation has attracted widely interest,not only because of the importance of arylphosphonates or heterocyclic aryl phosphonates in the organic synthesis and pharmacochemistry,but also their derivatives are widely used as ligands in the synthesis of metal catalysts.Phosphine-containing indole derivatives represent a special skeleton of phosphorus-nitrogen heterocycles.They represent important framework of drug molecules,and widely used in organic materials,as well as important ligands and intermediates in organic synthesis.Therefore,the synthesis of these type compounds has drawn much concern.The compound containing benzimidazole fragment show a wide range of biological activities and pharmacological activities,and own a variety of features such as anticancer,antifungal,anti-inflammatory,treatment of hypoglycemia and physiological disorders,which hold an important position in medicinal chemistry.Due to the special chemical property of NH,it is necessary to achieve N-protection of benzimidazole during their derivation.In addition,realization of N-functionalized compounds is an important intermediate for organic synthesis.On the other hand,two nitrogen atoms in benzimidazole can promote hydrogen bonding to enzyme or to DNA in the organism.These ideal functional features have also made benzimidazole as one of the research topic in biochemistry.The regioselectivity is of great importance in the preparation of molecules in organic chemistry.Herein,a novel method to enable the highly regioselective C3-phosphonation of free indoles has been developed.This transformation involves a radical and a hydrolysis procedure,and tolerates a range of functional groups,which gives an efficient route to toward the 1H-indol-3-ylphosphonic acid monoesters in on step.Sulfonylation of benzimidazole(benzotriazole)is achieved by N-S bond cleavage of N-fluorobisbenzenesulfonamide(NFSI)without catalyst.The reaction owned below advantages:the raw materials are easy to obtain,and low price,the price is low,the operation is simple,the reaction conditions is mild,and the system is carried out under the conditions of non-strong acid and non-strong base.