Hexapole [9]Helicene. (12th December 2018) - Wang, Yonggen
Abstract: Herein we present the first hexapole [9]helicene (H9H ). Co‐catalyzed [2+2+2] cyclotrimerization of a dinaphthopyrene (DNP) functionalized alkyne provides the hexaaryl benzene precursor2, which is transformed intoH9H via a dehydrocyclization reaction. Formation of each embedded [9]helicene involves forging of a new C−C bond, which stitches together two [4]helicene subunits of the neighboring DNP blades, reminiscent of the initial method Martin developed for the preparation of [9]helicene in the 1960s. Single‐crystal X‐ray analysis of both2 andH9H discloses their extremely distorted and crowded structural features. Chiral resolution, optical and electronic properties ofH9H are also presented.