Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany.
Science. 2017 Sep 1;357(6354):908-912. doi: 10.1126/science.aao0270. Epub 2017 Aug 10.
All-c-multifluorinated cycloalkanes exhibit intriguing electronic properties. In particular, they display extremely high dipole moments perpendicular to the aliphatic ring, making them highly desired motifs in material science. Very few such motifs have been prepared, as their syntheses require multistep sequences from diastereoselectively prefunctionalized precursors. Herein we report a synthetic strategy to access these valuable materials via the rhodium-cyclic (alkyl)(amino)carbene (CAAC)-catalyzed hydrogenation of readily available fluorinated arenes in hexane. This route enables the scalable single-step preparation of an abundance of multisubstituted and multifluorinated cycloalkanes, including all--1,2,3,4,5,6-hexafluorocyclohexane as well as cis-configured fluorinated aliphatic heterocycles.
全氟环烷烃表现出有趣的电子性质。特别是,它们在垂直于脂环的方向上表现出极高的偶极矩,这使得它们成为材料科学中非常理想的结构单元。由于它们的合成需要从非对映选择性预官能化的前体进行多步序列,因此很少有这样的结构单元被制备出来。在此,我们报告了一种通过铑催化的环状(烷基)(氨基)卡宾(CAAC)催化氢氟化芳基在己烷中的加氢反应来制备这些有价值的材料的合成策略。该路线能够以可扩展的单一步骤制备大量多取代和多氟代环烷烃,包括全-1,2,3,4,5,6-六氟环己烷以及顺式构型的氟化脂肪族杂环。