Leclerc Matthew C, Gabidullin Bulat M, Da Gama Jason G, Daifuku Stephanie L, Iannuzzi Theresa E, Neidig Michael L, Baker R Tom
Department of Chemistry and Biomolecular Sciences and Centre for Catalysis Research and Innovation, University of Ottawa, 30 Marie Curie, Ottawa, Ontario K1N 6N5, Canada.
Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
Organometallics. 2017 Feb 27;36(4):849-857. doi: 10.1021/acs.organomet.6b00908. Epub 2017 Feb 6.
Herein, a recently reported polyfluoroalkenyl imidazolium salt is shown to react with nitrogen-, oxygen- and sulfur-based nucleophiles at the C position in a stereoselective and regioselective fashion, without the use of a transition metal. In contrast, reactivity with 1-methylimidazole demonstrates net substitution at C . This product reacts quantitatively with water, affording clean transformation of a difluoromethylene group to give an ,-unsaturated trifluoromethyl ketone. Further reactivity studies demonstrate that the difluoromethyl fragment of an N-heterocyclic fluoroalkene is capable of direct C-C bond formation with NaCp through loss of sodium fluoride and double C-F bond activation (Cp = cyclopentadienide). TD-DFT calculations of this product indicate that both the HOMO and LUMO are of mixed /* character and are delocalized over the N-heterocyclic and Cp fragments, giving rise to a very intense absorption feature in the UV-vis spectrum. Additionally, two carbonylmetalate-substituted fluorovinyl imidazolium complexes featuring Mn and Mo were isolated and fully characterized.
在此，一种最近报道的多氟烯基咪唑鎓盐被证明能在不使用过渡金属的情况下，以立体选择性和区域选择性的方式与基于氮、氧和硫的亲核试剂在C 位置发生反应。相比之下，与1-甲基咪唑的反应显示在C 处发生净取代。该产物与水定量反应，使二氟亚甲基基团发生完全转化，生成α,β-不饱和三氟甲基酮。进一步的反应性研究表明，N-杂环氟烯烃的二氟甲基片段能够通过氟化钠的消除和双C-F键活化与NaCp直接形成C-C键（Cp = 环戊二烯基）。该产物的TD-DFT计算表明，最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）均具有混合的σ/π特征，并在N-杂环和Cp片段上离域，从而在紫外-可见光谱中产生非常强烈的吸收特征。此外，还分离并完全表征了两种以Mn和Mo为特征的羰基金属取代的氟乙烯基咪唑鎓配合物。
