Optically active transistion-metal complexes. 9.1 A general stereoselective route to a-chiral (R)-tricarbonyl (h6-ethylbenzene)chromium complexes. Novel organometallic phosphine catalysts for the asymmetric hydrovinylation reaction

U. Englert, R. Haerter, D. Vasen, A. Salzer, E.B. Eggeling, D. Vogt

    Research output: Contribution to journalArticleAcademicpeer-review

    73 Citations (Scopus)

    Abstract

    Treatment of (R)-[{a-(dimethylamino)ethyl}-¿6-benzene]Cr(CO)3 with esters of chloroformic acid leads to stereoselective substitution of the dimethylamino group for a chloro substituent. The reaction can be extended to systems in which the chromium arene complex, after metalation, is diastereoselectively substituted in the ortho position with carbon and silicon electrophiles to generate planar chirality. The chloro group in turn can be replaced stereoselectively for various phosphorus, nitrogen, and oxygen nucleophiles. Both substitution reactions in the benzylic position proceed via retention of configuration. The addition of cyanide is not stereospecific. The phosphine derivatives are efficient catalysts for the enantioselective hydrovinylation of styrene to 3-phenyl-1-butene. X-ray crystal structures establish the absolute configuration of (R)-[(a-chloroethyl)¿6-benzene]Cr(CO)3, (R)-[{a-(diphenylphosphanyl)ethyl}-¿6-benzene]Cr(CO)3, and (pS,S)-[1-(a-cyanoethyl)-2-methyl-¿6-benzene]Cr(CO)3.
    Original languageEnglish
    Pages (from-to)4390-4398
    JournalOrganometallics
    Volume18
    Issue number21
    DOIs
    Publication statusPublished - 1999

    Fingerprint Dive into the research topics of 'Optically active transistion-metal complexes. 9.1 A general stereoselective route to a-chiral (R)-tricarbonyl (h6-ethylbenzene)chromium complexes. Novel organometallic phosphine catalysts for the asymmetric hydrovinylation reaction'. Together they form a unique fingerprint.

    Cite this