The chemistry of titanocene dipnictene and pnictinidene complexes

该项目旨在利用芳基取代的三正膦合成含磷分子，利用其对二茂钛前体的独特反应性。在与各种刘易斯碱的反应中使用Cp 2 Ti（P2 Ar 2）（Ar =芳基）类型的二茂钛络合物，预期P2 Ar 2-配体的反应性的增强，并且在第一步中获得前所未有的二茂钛η1-二膦络合物。而在下一步中，这些配合物将与N-杂环卡宾转化，以实现推拉稳定的双膦。也将研究类似的砷化合物。此外，在探索性工作包中，将探索对炔、腈或异腈的反应性以在Ti处构建含P杂环，然后可以通过金属转移反应释放，类似于已经用相关锆系统建立的反应。在另一个工作包中，将详细研究二茂钛前体Cp 2 Ti（btmsa）（btmsa = C2（SiMe 3）2）在膦PR 3和氧化膦OPR 3存在下对（ArPn）3（Pn = P，As）的反应性。这些研究预计将导致终端二茂钛膦和砷络合物的形成。亚膦络合物将用于建立钛-磷-维蒂希反应，以获得在磷烯单元上具有中间空间体积的磷烯。

This project aims to utilize aryl-substituted triphosphoranes for the synthesis of phosphorus-containing molecules by exploiting their unique reactivity towards titanocene precursors. Using titanocene complexes of the type Cp2Ti(P2Ar2) (Ar = aryl group) in reactions with a variety of Lewis bases, an enhancement of the reactivity of the P2Ar2-ligand is expected and to give access to unprecedented titanocene η1-diphosphene complexes in a first step. While in the next step these complexes will be converted with N-heterocyclic carbenes to realize push-pull stabilized diphosphenes. The analogous arsenic compounds will be investigated as well. Moreover, in an explorative work package the reactivity towards alkynes, nitriles or isonitriles will be explored to build P-containing heterocycles at Ti, which can then be released through transmetalation reactions, akin to what has been established with related zirconium systems. In another work package the reactivity of the titanocene precursor Cp2Ti(btmsa) (btmsa = C2(SiMe3)2) towards (ArPn)3 (Pn = P, As) in the presence of phosphines, PR3, and phosphine oxides, OPR3, will be studied in detail. These studies are expected to result in the formation of terminal titanocene phosphinidene and arsinidene complexes. The phosphinidene complexes will be used to establish a titana-phospha-Wittig reaction, to access phosphaalkenes with intermediate steric bulk on the phosphaalkene unit.