Stalder Tobias, Krischer Felix, Steinert Henning, Neigenfind Philipp, Gessner Viktoria H
Chair of Inorganic Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
Chemistry. 2022 Feb 7;28(8):e202104074. doi: 10.1002/chem.202104074. Epub 2022 Jan 5.
Although N-heterocyclic phosphenium (NHP) cations have received considerable research interest due to their application in organocatalysis, including asymmetric synthesis, phosphenium cations with other substitution patterns have hardly been explored. Herein, the preparation of a series of ylide-substituted cations of type [YPR] (with Y=Ph PC(Ph), R=Ph, Cy or Y) and their structural and coordination properties are reported. Although the diylide-substituted cation forms spontaneous from the chlorophosphine precursor, the monoylidylphosphenium ions required the addition of a halide-abstraction reagent. The molecular structures of the cations reflected the different degrees of electron donation from the ylide to the phosphorus center depending on the second substituent. Molecular orbital analysis confirmed the stronger donor properties of the ylide systems compared to NHPs with the mono-ylide substituted cations featuring a more pronounced electrophilicity. This was mirrored by the reaction of the cations towards gold chloride, in which only the diylide-substituted cation [Y P] formed the expected LAuCl] complex, while the monoylide-substituted compounds reacted to the chlorophosphine ligands by transfer of the chloride from gold to the phosphorus center. These results demonstrate the tunability of ylide-functionalized phosphorus cations, which should allow for further applications in coordination chemistry in the future.
尽管氮杂环鏻（NHP）阳离子因其在有机催化（包括不对称合成）中的应用而受到了广泛的研究关注，但具有其他取代模式的鏻阳离子却几乎未被探索。在此，我们报道了一系列[YPR]型（Y = PhPC(Ph)，R = Ph、Cy或Y）叶立德取代阳离子的制备及其结构和配位性质。虽然二叶立德取代阳离子可由氯膦前驱体自发形成，但单叶立德鏻离子则需要添加卤化物抽象试剂。阳离子的分子结构反映了取决于第二个取代基的叶立德向磷中心的不同程度的电子给予。分子轨道分析证实，与NHP相比，叶立德体系具有更强的给体性质，单叶立德取代阳离子具有更明显的亲电性。这在阳离子与氯化金的反应中得到了体现，其中只有二叶立德取代阳离子[YP]形成了预期的[LAuCl]配合物，而单叶立德取代化合物则通过将氯从金转移到磷中心而反应生成氯膦配体。这些结果证明了叶立德功能化磷阳离子的可调性，这有望在未来的配位化学中得到进一步应用。
