Synthesis and properties of novel sequentially fluorinated motifs in organic chemistry

氟与有机分子的结合在有机化学和化学工业的各个部门中发挥着越来越大的重大影响。含氟化合物占临床和临床前试验所有实体的20%，约30%的农化产品含有氟原子，这一事实强调了这一点。含氟化合物广泛应用于材料和电子显示领域（聚合物、液晶等）。其中许多是芳族氟化合物，但氟位于立体中心的化合物也越来越受到关注，实现不对称氟化的方法在过去十年中一直是有机化学领域一个严肃而广泛的国际目标。在这个研究计划中，我们正在制备和探索氟原子彼此相邻放置的化合物的性质。该计划将探索由三个、四个和六个氟原子沿链排列的化合物的合成。这些是有机化学中的新基序，它们的合成要求以受控和立体定向的方式引入氟，以便制备单个非对映异构体。C-F键具有独特的性质，可以影响有机分子的构象，在这些分子中，多个C-F键彼此相邻（相邻），这就产生了有利和不利的构象。这些基序的亲脂性将被研究，它们也将被附加到功能材料，如液晶上，以探索它们相对于已知化合物的行为。该方案还将探索三氟糖类似物的合成，其中三个相邻的羟基直接被三个氟原子取代。这种替换将有助于揭示糖中C-O键极性与C-OH基团氢键能力的重要性，特别是有越来越多的证据表明极性在生物分子的进化中是一个被低估但极其重要的因素。总的来说，该方案将使我们能够将有机氟化学发展到一个新的领域，但以一种与对有机分子的行为和性质的更主流的理解相关的方式，这些行为和性质在材料和生物化学部门具有商业意义。

The incorporation of fluorine into organic molecules plays an increasing and major impact in all sectors of organic chemistry and the chemical industry. This is emphasised by the fact that fluorine containing compounds constitute 20% of all entities in clinical and pre-clinical trials and around 30% of agrochemical products posess a fluorine atom. Fluorinated compounds are widely represented in the materials and electronic displays sectors (polymers, liquid crystals etc). Many of these are aromatic fluorine compounds however compounds where fluorine is located at a stereogenic centre are also enjoying an increasing profile, and methods of achieving asymmetric fluorination has been a serious and widespread international objective in organic chemistry over the last decade. In this research programme we are preparaing and exploring the properties of compounds which have fluorine atoms placed adjacent to each other. The programme will explore the synthesis of compounds with three, four and six fluorine atoms arranged along a chain. These are new motifs in organic chemistry and their synthesis demands that the fluorines are introduced in a controlled and stereospecific manner, such that individual diastereoiosmers are prepared. The C-F bond has unique properties which can influence the conformation of organic molecules, and in these molecules multiple C-F bonds are placed adjacent (vicinal) to each other, and this gives rise to favoured and disfavoured conformations. The lipophilicity of these motifis will be examined and also they will be appended to functional materials such as liquid crystals, to explore their behaviour relative to known compounds. The programme will also explore the synthesis of tri-fluoro sugar analogues where three vicinal OH groups are replaced directly by three fluorine atoms. Such a replacement will help to reveal the importance of the polarity of the C-O bond versus the hydrogen bonding ability of the C-OH group in sugars, particularly as there is growing evidence that polarity is an underestimated but extremely important factor in the evolution of bio-molecules. Overall the programme will allow us to develop organo-fluorine chemistry into new territory but in a way that is relevant to a much more mainstream understanding of the behaviour and properties of organic molecules that are of commercial significance in the materials and biological chemistry sectors.