Atom‐Efficient Synthesis of Alkynylfluoroborates Using BF3‐Based Frustrated Lewis Pairs. (6th October 2016)

• Record Type: Journal Article
• Authors: Iashin, Vladimir; Chernichenko, Konstantin; Pápai, Imre; Repo, Timo
• Is Part Of: Angewandte Chemie. Volume 128:Number 45(2016)
• Page Start: 14352
• Page End: 14356
• Publication Date: 2016-10-06
• Subjects: Alkine -- Amine -- Bortrifluorid -- C-H-Aktivierung -- Frustrierte Lewis-Paare; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201608520
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A sterically demanding amine, 1, 2, 2, 6, 6‐pentamethylpiperidine (PMP), forms a highly reactive Lewis acid–base pair with boron trifluoride. This pair reacts with terminal acetylenes to give the products of C(sp)−H borylation, previously unknown tri‐ and tetraalkynylboron compounds. Trialkynylfluoroborates can serve as surrogates of alkynyltrifluoroborates for C−C coupling reactions. Using aqueous NaOH, PMP can be recovered from its tetrafluoroborate salt, which is formed as a C−H borylation byproduct. Combining the discovered borylation reactivity with the PMP recovery provides a straightforward and atom‐efficient approach to synthetically useful alkynylfluoroborates.