English Intern
    Prof. Dr. W. A. Schenk

    Chiral Metal Complexes

    Numbers in square brackets refer to the List of Publications

    Chiral Phosphines & Chiral Complexes

    This is a field we have entered only recently. Out of our work on the use of transition metal complexes as chiral auxiliaries (see Sulfur Chemistry) a need for chiral chelate phosphines with special properties arose. As a first example, (2S,3S)-bis(dibenzophospholyl)butane, a rigid analog of the well-known (S,S)-CHIRAPHOS was synthesized and converted into a series of ruthenium complexes [89].

     

    (2S,3S)-Bis(dibenzophospholyl)butane
    Molecular Structure of [CpRu{(S,S)-(C12H8P)CHMeCHMe (PC12H8)}Cl]
    Molecular structure of (RRe,SP/SRe,RP)-[CpRe(NO){P(Me) (Ph)(2-C6H4OMe)}(CH3)]

    Following up on our earlier work on chiral (still racemic) rhenium thiolate and thioaldehyde complexes of the types [CpRe(NO)(PR3)(SCH2R')] and [CpRe(NO)(PR3)(S=CHR')]+ [70, 91, 93, 96] we began to investigate new methods to obtain such complexes in enantiomerically pure form. Quite promising in this regard were chiral, hemilabile (P,O)- and (P,S) ligands which could easily be converted into diastereomeric rhenium complexes. These complexes were found to undergo reversible chelate ring closure / ring opening reactions [118, 119].

     

    Structure of the cation (RRe,SP/SRe,RP)-[CpRe(NO) {P(Me)(Ph)(2-C6H4OMe)}(THF)]+
    Structure of the cation (RRe,SP/SRe,RP)-[CpRe(NO) {P(Me)(Ph)(2-C6H4NMe2)}]+
    Molecular structure of (RRe,SP)-[CpRe(NO){P(Me)(Ph) (2-C6H4NMe2)}(CH3)]

    Similar (P,N) ligands proved to be even more useful as they provided a direct access to enantiomerically pure half-sandwich rhenium complexes through a diastereoselective proton transfer step [122].

    These complexes will now be investigated as templates in diastereoselective addition reactions of coordinated ligands.

     

    Kontakt

    Universität Würzburg
    Sanderring 2
    97070 Würzburg

    Tel.: +49 931 31-0
    Fax: +49 931 31-82600

    Suche Ansprechpartner

    Sanderring Röntgenring Hubland Nord Hubland Süd Campus Medizin