title: Atom-Efficient Synthesis of Alkynylfluoroborates Using BF3-Based Frustrated Lewis Pairs.
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.
authors.affiliation: Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, FI-, 00014, Helsinki, Finland.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Iashin
authors.affiliation: Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, FI-, 00014, Helsinki, Finland. kochern@gmail.com.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Chernichenko
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-, 1117, Budapest, Hungary.
authors.forename: Imre
authors.initials: I
authors.lastname: Pápai
authors.affiliation: Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, FI-, 00014, Helsinki, Finland. timo.repo@helsinki.fi.
authors.forename: Timo
authors.identifier: 0000-0002-3116-6199
authors.initials: T
authors.lastname: Repo
keywords: C−H activation; alkynes; amines; boron trifluoride; frustrated Lewis pairs