Ion-Functionalized Silver(I) Carboxylates: Synthesis and Application in Ru-Catalyzed Olefin Metathesis Reaction
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on-Functionalized Silver(I) Carboxylates: Synthesis and Application in Ru-Catalyzed Olefin Metathesis Reaction Xiao-Lu Chena,†, Xiang-Yu Lia,†, Shuai-Shuai Lia, Xue Baia, Tao Lia, Erukala Yadaiah Goudb, Chong-Min Zhonga,*, and Ya-Jie Zuoc,** a College
of Chemistry and Pharmacy, Northwest A&F University, Yangling, 712100 China of Life Science, Northwest A&F University, Yangling, 712100 China c College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100 China e-mail: *[email protected]; **[email protected] b College
Received September 9, 2020; revised October 7, 2020; accepted November 8, 2020
Abstract—The Grubbs–Hoveyda catalysts have a wide range of applications in catalyzed formation of the carboncarbon double bonds. In this study, several imidazolium- functionalized or pyridinium-functionalized silver carboxylates have been prepared, and their reaction with Grubbs–Hoveyda 2nd generation (G–H 2nd) catalyst leads a new type of processes. Activity and selectivity of the catalysts have been preliminarily evaluated using cross olefin metathesis reactions. Keywords: silver(I) carboxylates, ionic-function, ruthenium catalyst, olefin metathesis
DOI: 10.1134/S1070363220110237 INTRODUCTION The Ru-catalyzed olefin metathesis reaction leading to formation of carbon-carbon bonds is widely employed in chemical synthesis [1–4]. Design of well-defined ruthenium alkylidenes via modifying both steric and electronic properties of the ligands leads to development of a wide range of versatile olefin metathesis catalysts. Recently, replacement of chlorine ions in Grubbs’s ruthenium catalysts by other anionic ligands has received close attention. Grubbs and co-workers reported the first example of replacing chlorine in Ru(=CH–CH=CPh2)· Cl2(PPh3)2 with trifluoroacetate [5]. Shortly after, the first stable trifluoroacetate coordinated Grubbs 1st generation catalyst [6] was prepared. However, the catalyst was only moderately active for internal alkene, probably due to its dimer structure. Many other electron-withdrawing ligands, such as trifluoromethanesulfonate, fluoroalkyl carboxylates and pentafluorophenolate [7–10], and trialkoxysilyl substituted carboxylate [11] were used in reactions with Grubbs–Hoveyda 2nd generation catalyst. However, these catalysts usually were less stable/ active than G–H 2nd catalyst and gave E/Z mixtures in cross metathesis reactions. The effects of sulfonate and phosphate ligands on E/Z selectivity [12] has been †
Deceased.
studied. Highly Z-selective catalysts were developed by Grubbs [13], Hoveyda [14], and Wang et al. [15]. Besides, the E/Z-selectivity can be achieved by changing the structure of the anionic ligands [16]. However, most of the reported catalysts with replaced chlorine showed low or moderate activity. Therefore, design of more active and stereoselective Ru catalysts for olefin metathesis is still quite desirable. Previously we studied magnetic nano-particles supported G–H 2nd type catalysts [17, 18] and found that ionic functionalized Hoveyda carbene liga
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