Innovative Syntheses of Cyano(fluoro)borates: Catalytic Cyanation, Electrochemical and Electrophilic Fluorination. Issue 50 (4th August 2020)

• Record Type: Journal Article
• Authors: Drisch, Michael; Bischoff, Lisa A.; Sprenger, Jan A. P.; Hennig, Philipp T.; Wirthensohn, Raphael; Landmann, Johannes; Konieczka, Szymon Z.; Hailmann, Michael; Ignat'ev, Nikolai V.; Finze, Maik
• Is Part Of: Chemistry. Volume 26:Issue 50(2020)
• Page Start: 11625
• Page End: 11633
• Publication Date: 2020-08-04
• Subjects: cyanoborates -- electrochemical fluorination -- fluorination -- fluoroborates -- ionic liquids; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202002324
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Different types of high‐yield, easily scalable syntheses for cyano(fluoro)borates Kt[BF n (CN)4− n ] ( n= 0–2) (Kt=cation), which are versatile building blocks for materials applications and chemical synthesis, have been developed. Tetrafluoroborates react with trimethylsilyl cyanide in the presence of metal‐free Brønsted or Lewis acid catalysts under unprecedentedly mild conditions to give tricyanofluoroborates or tetracyanoborates. Analogously, pentafluoroethyltrifluoroborates are converted into pentafluoroethyltricyanoborates. Boron trifluoride etherate, alkali metal salts, and trimethylsilyl cyanide selectively yield dicyanodifluoroborates or tricyanofluoroborates. Fluorination of cyanohydridoborates is the third reaction type that includes direct fluorination with, for example, elemental fluorine, stepwise halogenation/fluorination reactions, and electrochemical fluorination (ECF) according to the Simons process. In addition, fluorination of [BH(CN)2 {OC(O)Et}] − to result in [BF(CN)2 {OC(O)Et}] − is described. Abstract : Three different convenient synthetic routes towards cyano(fluoro)borates, which are versatile building blocks, especially for room temperature ionic liquids, have been developed using easily accessible starting materials.