1,3-Diazolyl functionalized organopropylsilatranes: Synthesis and structural characterization

This work aims at the synthesis of unsubstituted and 3,7,10-trimethylsubstituted organopropylsilatranes by the reaction of 1,3-diazoles, viz. benzimidazole and 2-isopropylimidazole with 3-chloropropyltriethoxysilane which results in the triethoxysilanes: N-(3-triethoxysilylpropyl) benzimidazole (3) and N-(3-triethoxysilylpropyl)-2-isopropylimidazole (4). In the presence of a base, these silanes undergo transesterification reaction with triethanolamine (1) and tris(isopropanol) amine (2) thus forming the corresponding silatranes, N-(3-silatranylpropyl) benzimidazole (5), N-[3-(3,7,10-trimethylsilatranyl) propyl] benzimidazole (6), N-(3-silatranylpropyl)-2-isopropylimidazole (7), N-[3-(3,7,10-trimethylsilatranyl) propyl]-2-isopropylimidazole (8). Among these novel silatranes, which have been characterized by elemental analysis, IR, H-1, C-13 NMR spectroscopy, mass spectrometry and thermogravimetric analysis, the structure of silatrane (5) has been deduced by single crystal X-ray diffraction analysis. (C) 2014 Elsevier B.V. All rights reserved.