Synthesis of a new type of water-soluble phosphines by addition of hydrophilic thiols to vinylphosphines. Preparation of the rhodium and palladium complexes

Article abstract of DOI:10.1002/prac.19973390106

Commercially available ω-thioalkane sodium sulfonates could easily be added to mono-, bi- and trivinylphosphines. The two-phase system became homogeneous by stirring. The products (1-6, 11) were characterized as phosphinoethyl-sulfonatoalkyl-thioethers with an unexpected high water solubility and with defined P/S ratios from 1/2, 1/4 and 1/6. All thioetherphosphines were characterized by ¹H, ¹³C and ³¹P NMR spectroscopy, IR spectroscopy and elemental analysis. Addition occurs only at pH >7 and in the absence of strong electrophiles to avoid the formation of phosphonium compounds. L-Cysteine ethyl ester (8) and 2-aminoethanethiol (9) react exclusively at the thiol group. The first complexes with Pd(II), Rh(III) and Rh(I) show a participation of the thioether group in the coordination.