Phosphinine- and Phosphacyclohexadienyl-Complexes: Novel Phosphorus Compounds for the Activation of Small Molecules and for Homogeneous Catalytic Reactions

在成功的第一个资助期的基础上，Wolf（雷根斯堡大学）和m<e:1>勒（柏林自由大学）研究小组之间的联合项目将继续进入下一阶段。本课题主要研究吡啶的高级同系物h<s:1> kkel -aromatic λ3σ2- phosphahinines （phosphabenes）。由于其多样的配位方式和良好的π-受体性质，这些配体表现出极其多样的配位化学性质。特别是，它们非常适合稳定低氧化态过渡金属配合物，与小分子活化均相催化有关。此外，膦可以通过与有机锂或格氏试剂反应转化为阴离子1- r -磷酸环己二烯，这也是过渡金属的配体。因此，膦及其衍生物可用于接触不寻常的金属配合物和金属团簇。在第一个资助期内，许多最初设想的关于膦基过渡金属配合物或磷酸环己二烯阴离子的合成和反应性的想法都成功地实现了。研究结果的多样性保证了第二阶段的化学研究将是非常多方面的，除了对基本配位化学性质的进一步研究外，在（不对称）催化领域的应用将是特别关注的重点。将追求以下主要目标：i)开发双、三齿膦以及手性膦及其配位化合物；ii)用膦基Co-和fe -配合物激活小分子iii)钴催化的氢甲酰化和氢化反应；iv)与轴手性1- r -磷酸环己二烯阴离子的加氢功能化反应。我们两个研究小组的专业知识（AK Wolf：高活性金属阴离子的合成、处理和应用；AK m<e:1> ller：合成、反应性、配位化学和功能化膦的应用）将对成功实施这些计划中的广泛研究至关重要。

Building on a successful first funding period, the joint project between the Wolf (University of Regensburg) and Müller (Free University of Berlin) research groups will be continued into the next phase. This research project focuses on the Hückel-aromatic λ3σ2-phosphinines (phosphabenzenes), which are the higher homologues of pyridines. Due to their diverse coordination modes and good π-acceptor properties, these ligands exhibit an extremely versatile coordination chemistry. In particular, they are highly suitable for the stabilization of low-oxidation state transition metal complexes, relevant for small molecule activation homogeneous catalysis. Furthermore, phosphinines can be converted into anionic 1-R-phosphacyclohexadienyls by reaction with organolithium or Grignard reagents, which are also of interest as ligands for transition metals. Phosphinines and their derivatives can thus be used to access unusual metal complexes and metal clusters. In the course of the first funding period, many of the originally postulated ideas for the synthesis and reactivity of phosphinine-based transition metal complexes or phosphacyclohexadienyl anions were successfully implemented. The diversity of the results promises a very multifaceted chemistry in the second phase, where, in addition to further research into the basic coordination chemical properties, applications in the field of (asymmetric) catalysis will be particularly in the focus. The following major aims will be pursued: i) development of bi- and tridentate phosphinines as well as chiral phosphinines and their coordination compounds; ii) activation of small molecules with phosphinine-based Co- and Fe-complexes iii) cobalt-catalyzed hydroformylation and hydrogenation reactions; iv) hydrofunctionalization reactions with axially-chiral 1-R-phosphacyclohexadienyl anions. The expertise of our two research groups (AK Wolf: synthesis, handling and application of highly reactive metallate anions; AK Müller: synthesis, reactivity, coordination chemistry and application of functionalized phosphinines) will be crucial for the successful implementation of these planned extensive studies in the second funding period.