Releasing Antiaromaticity in Metal-Bridgehead Naphthalene

Authors: 
Chun Tang, Yu Zhao, Jingjing Wu, Zhixin Chen, Liu Leo Liu, Yuan-Zhi Tan, Jun Zhu*, and Haiping Xia*
Journal: 
J. Am. Chem. Soc.
Year: 
2021
Volume: 
143
FirstPage-LastPage: 
15587–15592
TOC: 
Abstract: 

As a fundamental chemical property, aromaticity guides the synthesis of novel structures and materials. Replacing the carbon moieties of aromatic hydrocarbons with transition metal fragments is a promising strategy to synthesize intriguing organometallic counterparts with a similar aromaticity to their organic parents. However, since antiaromaticity will endow compound instability, it is a great challenge to obtain an antiaromatic organometallic counterpart based on such transition metal replacement in aromatic hydrocarbons. Here, we report an efficient aromaticity transformation on aromatic naphthalene through the bridgehead replacement of an osmium fragment, leading to the unprecedented synthesis of metal-bridgehead naphthalene featuring a highly twisted structure as confirmed by X-ray crystallography characterization. Such a twisted conformation works together with its phosphonium substituents to release the antiaromaticity in the planar conformation of the metal-bridgehead naphthalene. Our findings prove the bridgehead involvement of transition metals in unexpected aromaticity modifications and open an avenue for novel metal-bridgehead complexes.

https://pubs.acs.org/doi/10.1021/jacs.1c08106

Doi: 
10.1021/jacs.1c08106