SYNTHESIS OF ALLYL-TRANSITION METAL COMPLEXES BY PHASE TRANSFER CATALYZED REACTIONS OF METAL CARBONYL HALIDES. III. CONSIDERATIONS OF THE MECHANISMS

Article abstract of DOI:10.1016/S0022-328X(00)92615-9

Mechanisms are proposed for the hydroxide ion-initiated reactions of metal carbonyl halides which lead to allyl-transition metal complexes under phase transfer conditions.Evidence is presented for intermediate anionic metallocarboxylic acids in reactions leading to η³-allyl products of molybdenum, iron, ruthenium and magnanese, whereas η¹ complexes are shown to result from halide displacement reactions in which simple metal carbonyl anions are generated.In some cases phosphorus-containing ligands inhibit the hydroxide-promoted reactions of metal carbonyl halideswith allyl bromide; a rationale involving decreased acidity of the carbonyl ligands is presented. syntheses of η³-C3H5Mn(CO)3P(OCH3)3 and η³-C3H5Mn(CO)22 by phase transfer catalysis are also described.