Phosphiranes as Ligands for Platinum Catalysed Hydrosilylations

Highly Strained Organophosphorus Compounds

“…[65] BABAR-Phos 54, [66] on the other hand, in which the PCC ring is incorporated into a polycyclic framework, is much more robust and allows the synthesis of fairly stable Rh(I) and Pt(0) complexes, which are active hydrosilylation [67] and recyclable hydroboration catalysts. [68] The metallaphosphetane formation with BABAR-Phos was found to be reversible and controllable by the co-ligands.…”

“…[64] All geometries were optimized using the analytical gradient method implemented by Versluis and Ziegler, [65] including relativistic effects by the zero-order regular approximations (ZORA). [66] The 31 P NMR chemical shift tensors were calculated with ADF's NMR program, [67] with an all-electron basis set for the phosphorus atoms. The total isotropic shielding tensors were referenced against PMe 3 , which has a value of 353.5 and an experimental chemical shift at δ 31 P = -62 with respect to 85% H 3 PO 4 .…”

Unexpected Thermal Reactivity of Phosphirano‐[1,2]thiaphosphole P–W(CO)5 Complexes

“…[2] Owing to the strong pyramidalization at the phosphorus, the ligand properties of phosphiranes are expected to be different to those of common acyclic phosphanes because a rather weak σ-donor character is paired with a significant π-accepting ability. [3][4][5] However, many phosphiranes appear to be less suited as ligands because they are chemically quite reactive. This problem is solved by the introduction of bulky substituents to reduce the reactivity of the phosphorus atom [3] or by the incorporation of the latter into a rigid polycyclic ring system to suppress the decomposition by a [2+1] cycloreversion.…”

“…This problem is solved by the introduction of bulky substituents to reduce the reactivity of the phosphorus atom [3] or by the incorporation of the latter into a rigid polycyclic ring system to suppress the decomposition by a [2+1] cycloreversion. By taking the latter approach, Grützmacher and coworkers have designed the BABAR-Phos class of phosphiranes, [4][5][6][7] which were found to form fairly stable Rh I and Pt 0 complexes that could be used as hydrosilylation [4] and hydroboration [8] catalysts.…”

Dibenzophosphasemibullvalen

“…[3][4][5] Dies veranlasste uns, die Synthese eines Phosphoranalogons von Dibenzosemibullvalen (II, X= CH) [6] zu versuchen. Stabile Derivate eines Dibenzoazasemibullvalens (III, X = N) sind bereits bekannt.…”