Combining planar and central chirality in ferrocene thiophosphine-sulfoxides

Novel chiral ferrocenylthiophosphine–sulfoxide and phosphine–sulfoxide derivatives possessing planar chirality for the ferrocene moiety and central chirality at the sulfur atom have been synthesized. These ligands can be obtained as pure diastereoisomers in both racemic and enantiomerically pure forms. Complete characterization by XRD analysis has allowed the assignment of the absolute configuration in each case. Preliminary coordination studies of the phosphine–sulfoxide ligands on platinum are also reported. These show chelating complexation by the phosphorous and sulfur atoms.

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(RFc,SS)-2-Thiodiphenylphosphino-(phenyl-sulfoxymethyl)ferroceneC29H25PS2O[α]D21=-100.2 (c 0.49, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,SS)

(RFc,RS)-2-Thiodiphenylphosphino-(phenyl-sulfoxymethyl)ferroceneC29H25PS2O[α]D21=+14.2 (c 0.49, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,RS)

(RFc,RS)-2-Thiodiphenylphosphino-(ethyl-sulfoxymethyl)-ferroceneC25H25PS2O[α]D21=-110.2 (c 0.50, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,RS)

(RFc,SS)-2-Thiodiphenylphosphino-(ethyl-sulfoxymethyl)-ferroceneC25H25PS2O[α]D21=+32.1 (c 0.505, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,SS)

(RFc,SS)-2-Thiodiphenylphosphino-(tert-butyl-sulfoxymethyl)-ferroceneC27H29PS2O[α]D21=-152.2 (c 0.50, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,SS)

(RFc,RS)-2-Thiodiphenylphosphino-(tert-butyl-sulfoxymethyl)-ferroceneC27H29PS2O[α]D21=+5.0 (c 0.515, CHCl3)Source of chirality: ephedrineAbsolute configuration: (RFc,RS)