Air-Stable, Compact, Caged Trialkylphosphines (SMAPs): Synthesis, Properties and Applications to Homogeneous and Heterogeneous Catalysis

Abstract

Synthesis, properties and applications to transition metal catalysis of extremely compact, caged trialkylphosphines (SMAPs) in the form of molecules or silica-supported materials are described. The new phosphines are air-stable despite their strongly electron-rich character. Soluble phosphine Ph-SMAP showed high ligand performance in the Rh-catalyzed hydrosilylation and hydrogenation of ketones. The silica-supported SMAP (Silica-SMAP) displayed a unique coordination behavior to form 1:1 P-metal complexes, which appeared to be useful as platforms to create highly active catalytic centers. As a result, Silica-SMAP enabled the Rh-catalyzed hydrosilylation and hydrogenation of extremely hindered ketones such as di-tert-butyl ketone as well as Ir-catalyzed directed ortho-borylation of functionalized arenes with a broad substrate scope.

Six-Membered Rings With One Phosphorus Atom

“…The reduction of phosphine sulfides can be performed utilizing the hexachlorodisilane in refluxed benzene (Scheme 20). 35 Moreover, desulfuration of the P-fused double helicene 55 was achieved in the presence of 20 equivalents of triethylphosphine at 60 °C (Scheme 21). 37 The Raney-Ni reagent was also effective in reducing phosphine sulfide 57 within 3 h at room temperature (Scheme 22).…”