Unexpected Regiospecific Reduction of the Double Bond by NaBH<sub>4</sub> in 2‐(1‐Methyl/1H‐benzimidazole‐2‐yl)‐3‐aryl‐acrylonitrile
作者:P. K. Dubey、P. V. V. Prasada Reddy
DOI:10.1080/00397910701397177
日期:2007.7.1
Condensation of (1H-benzimidazole-2-yl)-acetonitrile 1 with aromatic aldehydes in 5% NaOH solution gave the corresponding 2-(1H-benzimidazole-2-yl)3-aryl-acrylonitrile 2, which on treatment with NaBH4 in ethanol unexpectedly gave 2-(1H-benzimidazole-2-yl)-3-aryl-propionitrile 3 by the regiospecific reduction of the double bond. Shaking a solution of 2 with H-2/Pd-C in methanol also gave 3. Reaction of 2 with DMS gave the corresponding N-methylated analogue 5, which also with NaBH4 gave 6, once again by the regiospecific reduction of the double bond as in the case of 1-demethylated analogue ( i. e., 2).
REGAILA H. A. A.; EL-BAYOUKI KH.; HAMMAD M., EGYPT. J. CHEM., 1977 (1979), 20, NO 2, 157-166
Synthesis of 1,2-Fused Benzimidazoles by Amine-Initiated [3 + 3] Annulations of β′-Acetoxy Allenoates with 1C,3N-Bisnucleophiles
作者:Chunjie Ni、Shiyu Pan、Chen Yuan、Shuya Qin
DOI:10.1021/acs.joc.3c00679
日期:2023.7.7
well with a wide substrate scope, delivering novel 1,2-fused benzimidazole derivatives in moderate to good yields. In addition, preliminary attempts on the asymmetric version of this reaction have been explored by usingcinchonaalkaloid-based tertiary amines.