Tridentate Lewis-acids based on triphenylsilane

Several derivatives of the propeller-shaped ortho-substituted triphenylsilanes, carrying metal-or silicon-based acceptor groups, are reported. They were synthesized starting from tris(2-bromophenyl) fluorosilane, tris(2-vinylphenyl) fluorosilane and tris(2-ethynylphenyl) fluorosilane to generate a scope of Lewis-acidic molecules with different cavities. An improved synthetic protocol for donor-free tris(2-lithiophenyl) silanes is described. First attempts in host-guest chemistry to probe the binding between a threefold alane-functionalised ortho-substituted triphenylsilane and a tridentate Lewis-basic guest molecule are presented. The synthesis and a first molecular structure determination in the crystalline state of a bisma-silatriptycene is reported.