Stereoselective Synthesis of a Topologically Chiral Solomon Link.

With the help of retrosynthetic analysis, we have realized the highly anticipated stereoselective synthesis of a topologically chiral Solomon link, by taking advantage of coordination-driven self-assembly and chiral induction by axially chiral ligands. Combination of the ligands (R or S)-2,2'-diethoxy-1,1'-binaphthyl-6,6'-bis(4-vinylpyridine) (R-L or S-L) with the binuclear iridium complex [Cp*2Ir2(DHBQ)(OTf)2] (Ir-B(OTf)2, H2DHBQ = 2,5-dihydroxy-1,4-benzoquinone) allows diastereoselective synthesis of the topological enantiomers P (Ir-1P) or M (Ir-1M) of a Solomon link, respectively. The main driving force for the formation of the Solomon link is the π-π interactions between chiral ligands.