Phosphorus heterocycles from 2‐(2‐aminophenyl)‐1H‐benzimidazole

Abstract

We report the syntheses of unsaturated six-membered heterocycles bearing tri-, tetra-, and pentacoordinated phosphorus atoms derived from 2-(2-aminophenyl)-1H-benzimidazol (1). 3, heterocycle. C

Boron coordination compounds derived from 2-phenyl-benzimidazole and 2-phenyl-benzotriazole bidentate ligands

“…The 19 F chemical shifts of the benzimidazole compounds are similar to those found for a BF 2 derivative of 2-aminoguanidine benzimidazole (À135.2 ppm), Scheme 2 [5]. The benzotriazole compounds 12-13 present a shift in the 19 F signals to lower frequencies (À142.0 to À144.5 ppm) with respect to the benzimidazole derivative (À136.4 ppm) which denotes that 19 F is sensitive to the nature of the azole ring, Table 1. 1 H and 13 C spectra of compounds 6-9, 11-13 showed that all atoms have different resonances indicating that the N ?…”

“…Derivatives of compound 5 and elements of group 4 have been employed as catalysing agents [17]. Compounds 1 and 2 have been used to prepare phosphorus heterocycles [18,19]. Haloboron heterocycles derived from compound 2 are known.…”

Phosphorus heterocycles from 2‐(2‐hydroxyphenyl)‐1H‐benzimidazole

“…The resulting orange solution was filtered and concentrated in vacuum to give 130 mg of compound 2 as a yellow oil, 95%. [4,5]decane (9) To a solution of 40 mg (0.14 mmol) of 2 in CDCl 3 (0.7 ml) placed in an NMR tube, 30 mg (0.14 mmol) of 3,5-di-tert-butyl-1,2-benzoquinone was added.…”

“…Compound 9 was formed after heating the mixture in a water bath at 50 • C for 3 h. It was not isolated due to its fragility, the 92% yield was calculated from the 31 [4,5]decane (22) Thirty milligrams (0.11 mmol) of 5 and 20 mg (0.11 mmol) of 3,5-di-tert-butyl-1,2-benzoquinone were mixed. The reaction was instantaneous, 67% yield.…”