Department of Chemistry, University of Helsinki, A. I. Virtasen aukio 1, FI-, 00014, Helsinki, Finland.
Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-, 1117, Budapest, Hungary.
Angew Chem Int Ed Engl. 2016 Nov 2;55(45):14146-14150. doi: 10.1002/anie.201608520. Epub 2016 Oct 6.
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.
一个空间位阻要求苛刻的胺，1,2,2,6,6-五甲基哌啶（PMP），与三氟化硼形成一个高反应性的路易斯酸碱对。该对与末端炔烃反应，生成之前未知的 C(sp)-H 硼化产物，三炔基硼酸酯可以作为炔基三氟硼酸盐的替代品，用于 C-C 偶联反应。使用水合氢氧化钠，PMP 可以从其四氟硼酸盐盐中回收，该盐是作为 C-H 硼化的副产物形成的。将发现的硼化反应性与 PMP 的回收相结合，为合成有用的炔基硼酸酯提供了一种直接且原子经济性的方法。
