Kumar Tarun, Yang Yan, Sghaier Sirine, Zaid Yassir, Le Goff Xavier F, Rousset Elodie, Massicot Fabien, Harakat Dominique, Martinez Agathe, Taillefer Marc, Maron Laurent, Behr Jean-Bernard, Jaroschik Florian
ICGM, Univ. Montpellier, CNRS, ENSCM, 34090, Montpellier, France.
ICMR, UMR 7312, Université de Reims Champagne Ardenne, CNRS, 51097, Reims, France.
Chemistry. 2021 Feb 24;27(12):4016-4021. doi: 10.1002/chem.202005239. Epub 2021 Feb 1.
The development of new fluorine-containing building blocks and their efficient synthetic access is currently a challenging research field. Herein, the highly regio- and stereoselective addition of a large range of aldehydes onto trifluoromethylated benzofulvenes was achieved using a simple La/I /DIBAL-Cl system via a selective C-F bond activation process. This versatile methodology provided homodienyl alcohols bearing a terminal CF -alkene with potential further applications, as shown by the dehydration to the first benzofulvenes carrying a difluorovinyl group. In addition, for certain electron-poor aldehydes, unprecedented ipso substitution of the CF group in a diene was observed, which, according to DFT studies, is related to the presence of the large, Lewis-acidic lanthanum metal.
新型含氟结构单元的开发及其高效合成方法目前是一个具有挑战性的研究领域。在此，通过简单的镧/碘/二异丁基氢化铝-氯体系，经由选择性碳-氟键活化过程，实现了多种醛对三氟甲基化苯并富烯的高区域和立体选择性加成。这种通用方法提供了带有末端碳-氟烯烃的同二烯醇，具有潜在的进一步应用价值，如通过脱水反应得到首个带有二氟乙烯基的苯并富烯所示。此外，对于某些缺电子醛，观察到二烯中三氟甲基的前所未有的本位取代，根据密度泛函理论研究，这与大体积的路易斯酸性镧金属的存在有关。
