Highly enantioselective synthesis of silahelicenes using Ir-catalyzed [2+2+2] cycloadditionElectronic supplementary information (ESI) available: CCDC reference number 844257. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c1cc16762f

Silahelicenes, which contain two silole moieties in a helically chiral structure, were synthesized by a chiral Ir-catalyzed intermolecular [2+2+2] cycloaddition of tetraynes with diynes along with a Ni-mediated intramolecular [2+2+2] cycloaddition. The photophysical properties of the obtained highly enantiomerically enriched silahelicenes (up to 93% ee) were also measured. Helically chiral silahelicenes were synthesized by a chiral Ir-catalyzed intermolecular cycloaddition of tetraynes with diynes along with a Ni-mediated intramolecular cycloaddition.