Head‐to‐Tail Oligomerization by Silylene‐Tethered Sonogashira Coupling on Ag(111)
Head‐to‐Tail Oligomerization by Silylene‐Tethered Sonogashira Coupling on Ag(111)
复制标题
Ag(111)上硅烯系Sonogashira偶联的头尾齐聚
DOI：
10.1002/anie.202102882
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Kawai Shigeki
中科院分区：
文献类型：
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作者：
Sun Kewei;Sagisaka Keisuke;Peng Lifen;Watanabe Hikaru;Xu Feng;Pawlak R?my;Meyer Ernst;Okuda Yasuhiro;Orita Akihiro;Kawai Shigeki
表面合成是制备π共轭纳米材料的有效方法。在这里，我们证明了在银(111)表面上，硅乙炔和氯代部分氟化苯乙炔(SiCPFPEs)中(三甲基硅基)乙炔和氯苯基之间的Sonogashira化学选择性偶联。脱硅基Sonogashira偶联反应的化学选择性高达75 %，而竞争的乌尔曼偶联反应和脱硅基GLASER同源偶联反应则受到抑制。结合键分辨扫描隧道显微镜/原子力显微镜和密度泛函计算表明，低聚物是通过CH3-−-Si键在130 °C下活化，然后在200 °C高温下消除束缚而形成的分子间硅烯系链(-Me2Si-)。
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 (‐Me2Si‐) through CH3−Si bond activation at 130 °C and subsequent elimination of the tethers at an elevated temperature of 200 °C.