Synthesis of Pyridine-Fused Siloles by Palladium-Catalyzed Intramolecular Bis-Silylation

Akinobu Naka; Natsumi Shimomura; Hisayoshi Kobayashi

doi:10.1021/acsomega.2c03637

Synthesis of Pyridine-Fused Siloles by Palladium-Catalyzed Intramolecular Bis-Silylation

ACS Omega. 2022 Aug 16;7(34):30369-30375. doi: 10.1021/acsomega.2c03637. eCollection 2022 Aug 30.

Authors

Akinobu Naka¹, Natsumi Shimomura¹, Hisayoshi Kobayashi²

Affiliations

¹ Department of Life Science, Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima, Kurashiki, Okayama 712-8505, Japan.
² Professor Emeritus, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan.

Abstract

Silole derivatives are attracting significant attention as new functional materials with excellent electronic and photophysical properties. Thus, the development of synthesis methods to afford such derivatives is highly desirable. Herein, the synthesis of pyridine-fused siloles under the conditions of the Sonogashira coupling reaction is described. The reactions of 2-bromo-3-(pentamethyldisilanyl)pyridine (1) with ethynylbenzene derivatives in the presence of PdCl₂(PPh₃)₂-CuI as a catalyst afforded the corresponding pyridine-fused siloles (2a-2c) through intramolecular trans-bis-silylation. DFT calculations were also performed to understand the reaction mechanism. This paper is the first to report on the successful use of palladium catalysts in the trans-bis-silylation of alkynes with disilanes.