A Chiral 1,8-Anthrylene-Ethynylene Tetramer

Significance

The preparation of a chiral, three-dimensional, conjugated tetramer composed of 1,8-anthrylene-ethynylene groups is presented. Sonogashira couplings and selective deprotections of silyl-protected alkynes were used extensively for the synthesis of this compound (see scheme), an approach similar to that employed previously by Toyota and coworkers for the preparation of related achiral oligomers (Angew. Chem. Int. Ed. 2004, 43, 2248-2251). The conformational, photophysical, and chiroptical properties of the chiral tetramer were studied by NMR, UV-Vis, and CD spectroscopy. Separation of enantiomers was achieved on a milligram scale by preparative HPLC.