Silyl modification of biologically active compounds.: 11.: Synthesis, physico-chemical and biological evaluation of N-(trialkoxysilylalkyl)tetrahydro(iso,silaiso) quinoline derivatives

N-(trialkoxysilylalkyl) derivatives of 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline and 4,4-dimethyl-4-sila-1,2,3,4-tetrahydroisoquinoline were prepared and characterized by elemental analysis, H-1, C-13 and Si-29 NMR spectroscopy. In vivo psychotropic properties and in vitro cytotoxic effects of 3-[N-(1,2,3,4-tetrahydroisoquinolyl)]propyltriethoxysilanemethiodide and 3-[N-(1,2,3,4-tetrahydroisoquinolyl)]propylsilatrane are reported. Comparative study of Si-29 shifts in newly synthesized compounds suggested donor-acceptor interaction between nitrogen and silicon atom, which increased electron density at Si nuclei, revealing a stronger increment of N -> Si transannular bond in comparison with N -> Si alpha-effect. The molecular structure of 3-[N-(1,2,3,4-tetrahydroisoquinolyl)]propylsilatrane features a penta-coordinate silicon atom having CSiO3 pattern and Si...N intramolecular interaction. Copyright (c) 2005 John Wiley & Sons, Ltd.