Synthesis and properties of the first 1-silanaphthalene

The first 1-silanaphthalene, 4, was successfully synthesized by taking advantage of an efficient steric protection group, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt), and the aromaticity of 4 was discussed on the basis of its H-1, C-13, and Si-29 NMR, Raman, and UV/vis spectra together with theoretical calculations. In contrast to the thermal stability of the Tbt-substituted 2-silanaphthalene 2, 1-Tbt-1-silanaphthalene (4) undergoes a ready [2 + 4] dimerization reaction in solution even at room temperature, despite its stability in the solid state.