Access to Chiral Silicon Centers for Application to Circularly Polarized Luminescence Materials

Asymmetric arylation of secondary silanes catalyzed by a Pd-chiral phosphoramidite complex was developed for application to low-molecular-weight circularly polarized luminescence (CPL) materials. The asymmetric arylation provided a convenient, efficient synthetic method for a variety of chiral tertiary silanes (<b>2</b>–<b>21</b>), which were key intermediates for preparing the quaternary silicon center. A stepwise, one-pot procedure was used to transform the appropriate aryl iodide to the quaternary silane (<b>22</b>) with good yield and enantioselectivity. Among compounds synthesized in this work, four optically pure tertiary silanes (<b>18</b>–<b>21</b>) were selected to investigate the relationship between the structure and optical properties. Optically pure (<i>S,S</i>)-<b>21</b> displayed the highest CPL emission with a high fluorescence quantum yield (<i>g</i>_lum: +0.008, Φ_F: 0.42). This simple molecular design provides new strategies for developing small organic CPL dyes