Lin Jinxiong, Wossidlo Friedrich, Coles Nathan T, Weber Manuela, Steinhauer Simon, Böttcher Tobias, Müller Christian
Freie Universität Berlin, Institut für Chemie und Biochemie, Fabeckstr. 34/36, 14195, Berlin, Germany.
School of Chemistry, University of Nottingham, University Park Campus, Nottingham, NG7 2RD, UK.
Chemistry. 2022 Feb 1;28(7):e202104135. doi: 10.1002/chem.202104135. Epub 2022 Jan 20.
A phosphinine-borane adduct of a Me Si-functionalized phosphinine and the Lewis acid B(C F ) has been synthesized and characterized crystallographically for the first time. The reaction strongly depends on the nature of the substituents in the α-position of the phosphorus heterocycle. In contrast, the reaction of B H with various substituted phosphinines leads to an equilibrium between the starting materials and the phosphinine-borane adducts that is determined by the Lewis basicity of the phosphinine. The novel phosphinine borane adduct (6-B(C F ) ) shows rapid and facile insertion and [4+2] cycloaddition reactivity towards phenylacetylene. A hitherto unknown dihydro-1-phosphabarrelene is formed with styrene. The reaction with an ester provides a new, facile and selective route to 1-R-phosphininium salts. These salts then undergo a [4+2] cycloaddition in the presence of Me Si-C≡CH and styrene to cleanly form unprecedented derivatives of 1-R-phosphabarrelenium salts.
首次合成并通过晶体学表征了一种甲基硅官能化膦杂苯与路易斯酸B(C₆F₅)₃形成的膦杂苯 - 硼烷加合物。该反应强烈依赖于磷杂环α位取代基的性质。相比之下，B₂H₆与各种取代膦杂苯的反应导致起始原料与膦杂苯 - 硼烷加合物之间达到平衡，这由膦杂苯的路易斯碱度决定。新型膦杂苯硼烷加合物(6 - B(C₆F₅)₃)对苯乙炔表现出快速且容易的插入反应和[4 + 2]环加成反应活性。与苯乙烯反应形成了一种迄今未知的二氢 - 1 - 磷杂环辛四烯。与酯的反应为制备1 - R - 膦杂苯鎓盐提供了一条新的、简便且选择性的途径。这些盐在Me₃Si - C≡CH和苯乙烯存在下进行[4 + 2]环加成反应，可干净利落地形成前所未有的1 - R - 磷杂环辛四烯鎓盐衍生物。
