Activation of the B−F Bond by Diphenylcarbene: A Reversible 1,2-Fluorine Migration between Boron and Carbon

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• 作者：Dr. Paolo Costa ; Joel Mieres-Perez ; Nesli Ö ; zkan and Prof. Dr. Wolfram Sander
• 刊名：Angewandte Chemie International Edition
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：56
• 期：7
• 页码：1760-1764
• 全文大小：2010K
• ISSN：1521-3773

文摘

Experiments in low-temperature matrices reveal that triplet diphenylcarbene inserts into the very strong B−F bond of BF₃ in a two-step reaction. The first step is the formation of a strongly bound Lewis acid–base complex between the singlet state of diphenylcarbene and BF₃. This step involves an inversion of the spin state of the carbene from triplet to singlet. The second step requires visible-light photochemical activation to induce a 1,2-F migration from boron to the adjacent carbon atom under formation of the formal insertion product of the carbene center into BF₃. The 1,2-F migration is reversible under short-wavelength UV irradiation, thus leading back to the Lewis acid–base adduct.