Head-to-Tail Oligomerization by Silylene-Tethered Sonogashira Coupling on Ag(111).
Kewei SunKeisuke SagisakaLifen PengHikaru WatanabeFeng XuRémy PawlakErnst MeyerYasuhiro OkudaAkihiro OritaShigeki KawaiPublished in: Angewandte Chemie (International ed. in English) (2021)
On-surface synthesis is a powerful method for the fabrication of π-conjugated nanomaterials. Herein, we demonstrate chemoselective Sonogashira coupling between (trimethylsilyl)ethynyl and chlorophenyl groups in silylethynyl- and chloro-substituted partially fluorinated phenylene ethynylenes (SiCPFPEs) on Ag(111). The desilylative Sonogashira coupling occurred with high chemoselectivity up to 75 %, while the competing Ullmann and desilylative Glaser homocoupling reactions were suppressed. A combination of bond-resolved scanning tunneling microscopy/atomic force microscopy (STM/AFM) and DFT calculations revealed that the oligomers were obtained by the formation of intermolecular silylene tethers (-Me2 Si-) through CH3 -Si bond activation at 130 °C and subsequent elimination of the tethers at an elevated temperature of 200 °C.
Keyphrases
- room temperature
- atomic force microscopy
- high speed
- single molecule
- high resolution
- density functional theory
- ionic liquid
- molecular docking
- quantum dots
- highly efficient
- electron transfer
- molecular dynamics
- photodynamic therapy
- high throughput
- mass spectrometry
- visible light
- optic nerve
- transition metal
- tissue engineering
- electron microscopy