Oxygen‐ and Nitrogen‐Embedded Zigzag Hydrocarbon Belts

• Published in: Angewandte Chemie International Edition Vol. 59; no. 52; pp. 23649 - 23658
• Main Authors: Tan, Mei‐Ling, Guo, Qing‐Hui, Wang, Xue‐Yuan, Shi, Tan‐Hao, Zhang, Qian, Hou, Sheng‐Kai, Tong, Shuo, You, Jingsong, Wang, Mei‐Xiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 21-12-2020
• Edition: International ed. in English
• Subjects: Aromatic compounds; Belts; Chemical properties; Chemical reactions; Conformation; Fjords; Hydrocarbons; Nitrogen; nucleophilic aromatic substitution; octahydrobeltarenes; Palladium; palladium-catalyzed C−N bond formation; Redox properties; strained macrocycles; zigzag hydrocarbon belts; nucleophilic aromatic substitution; palladium-catalyzed C−N bond formation; strained macrocycles; octahydrobeltarenes; zigzag hydrocarbon belts
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202013149

Despite the aesthetically appealing structures and tantalizing physical and chemical properties, zigzag hydrocarbon belts and their heteroatom‐embedded analogues remain challenging synthetic targets. We report herein the synthesis of diverse O/N‐doped zigzag hydrocarbon belts based on selective bridging of the fjords of resorcin[4]arene derivatives through intramolecular SNAr and palladium‐catalyzed intermolecular C−N bond formation reactions. Preorganized conformations of mono‐macrocyclic, half‐belt and quasi‐belt compounds were revealed to facilitate cyclization reactions to construct heteroatom‐linked octahydrobelt[8]arenes. The acquired products had strained square‐prism‐shaped belt structures in which all six‐membered heterocyclic rings adopted an unusual boat conformation with equatorially configured alkyl groups. The unprecedented heteroatom‐bearing belts also exhibited different photophysical and redox properties to those of octahydrobelt[8]arene analogues.
Bridging all fjords of resorcin[4]arene derivatives by means of a macrocyclic‐conformation‐facilitated intramolecular nucleophilic substitution reaction and palladium‐catalyzed intermolecular C−N cross‐coupling led to the production of unprecedented oxygen‐ and nitrogen‐doped zigzag hydrocarbon belts (see structure). The heteroatom‐embedded belts exhibited markedly different photophysical and redox properties to those of their hydrocarbon analogues.