A new strategy for hyperconjugative antiaromatic compounds utilizing negative charges: a dibenzo[ b, f]silepinyl dianion

Shotaro Ito; Youichi Ishii; Kazuya Ishimura; Takuya Kuwabara

doi:10.1039/d1cc04434f

A new strategy for hyperconjugative antiaromatic compounds utilizing negative charges: a dibenzo[ b, f]silepinyl dianion

Chem Commun (Camb). 2021 Oct 28;57(86):11330-11333. doi: 10.1039/d1cc04434f.

Authors

Shotaro Ito¹, Youichi Ishii¹, Kazuya Ishimura², Takuya Kuwabara³

Affiliations

¹ Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
² X-Ability, Co., Ltd., Ishiwata Building 3rd Floor, 4-1-5 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
³ Department of Chemistry and Biochemistry, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan. Kuwabara.takuya@ocha.ac.jp.

PMID: 34636825
DOI: 10.1039/d1cc04434f

Abstract

Herein we propose a new strategy for hyperconjugative antiaromatic compounds utilizing negative charges and design the 5,5-diphenyldibenzo[b,f]silepinyl dianion (pseudo 16π-electron system) in which negative hyperconjugation occurs between the anionic π-cloud and the σ*(Si-Ph) orbital. Essentially, reduction of the dibenzo[b,f]silepin with lithium readily generated a dilithium salt of the dibenzosilepinyl dianion, and its hyperconjugative antiaromaticity has been evidenced by the upfield shifts of ¹H NMR signals and theoretical calculations, including large NICS_zz values and ACID plots.