The chemistry of titanocene dipnictene and pnictinidene complexes

本项目旨在利用芳基取代的三磷烷对二茂钛前体的独特反应性，合成含磷分子。利用Cp2Ti(P2Ar2) （Ar =芳基）型二茂钛配合物与多种路易斯碱反应，期望能提高P2Ar2配体的反应活性，并在第一步获得前所未有的二茂钛η -二膦配合物。下一步，这些配合物将与n -杂环碳烯进行转化，以实现推拉稳定的二膦。类似的砷化合物也将被研究。此外，在一个探索性的工作包中，将探索对炔、腈或异腈的反应性，以在Ti上建立含p的杂环，然后可以通过金属转化反应释放，类似于用相关的锆系统建立的反应。在另一个工作包中，将详细研究二茂钛前驱体Cp2Ti(btmsa) （btmsa = C2(SiMe3)2）在磷化氢、PR3和磷化氢氧化物OPR3存在下对（ArPn）3 （Pn = P, As）的反应性。这些研究预计将导致二茂钛末端膦烯和砷烯配合物的形成。磷烯配合物将用于建立钛-磷-维蒂格反应，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.