Hexapole [9]Helicene. Issue 2 (12th December 2018)

• Record Type: Journal Article
• Authors: Wang, Yonggen; Yin, Zhibo; Zhu, Yanpeng; Gu, Jiajian; Li, Yang; Wang, Jiaobing
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 2(2019)
• Page Start: 587
• Page End: 591
• Publication Date: 2018-12-12
• Subjects: chirality -- helicene -- nonplanar -- steric hindrance; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201811706
• Languages: English
• ISSNs: 1433-7851

Abstract

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. Abstract : New twist : The first hexapole [9]helicene with an extremely twisted structure has been synthesized and characterized. Formation of each embedded [9]helicene (see scheme, cyan) involves forging of a new C−C bond (purple) to stitch together two [4]helicene subunits, reminiscent of the initial approach Martin developed in the 1960s to make the pristine [9]helicene.