An efficient solidphasesynthesis of benzimidazoles is described. Polymer bound o-fluoronitroaromatic compound 2 was treated with an amine to give o-nitroaniline derivative 3. Reduction of 3 with NaBH4Cu(acac)2 followed by cyclization with an aryl imidate and cleavage with TFA gave 5. A library of benzimidazoles has been prepared in three steps in 70–95 % crude yield and 70–98 % purity. Final purified
Suzuki-type cross-coupling reaction of 1-benzyl-2-iodo-1H-benzimidazoles with aryl boronic acids: A regioselective route to N-alkylated 6-alkoxy-2-aryl-1H-benzimidazoles
作者:Jesús Ezquerra、Carlos Lamas、Alfredo Pastor、JoséL. García-Navío、Juan J. Vaquero
DOI:10.1016/s0040-4020(97)00795-3
日期:1997.9
The Suzuki-type cross-coupling reaction of 6-substituted 1-benzyl-2-iodo-1H-benzimidazoles with aryl boronic acids provided an efficient synthesis of the corresponding 2-ary-1H-benzimidazoles. The reaction was catalyzed by palladium(0) under different conditions depending on the aryl group substitution.