Manganese complexes nucleophilic reactions

In a comparative study, the reaction of nucleophiles with the analogous series of complex cations (C H Mee-, n = 0,2) Cr(CO)2NO was examined. In this case, only exo attack of H", D", and Me was observed (Connelly and Kelly, 1974). For reasons which are unclear, the reactivity of these chromium complexes with respect to nucleophilic attack is less than that of the manganese complexes. In any case, this alteration introduced by the cationic NO ligand does not produce any synthetic advantages over those obtained with a simple Cr(CO)3 group. 

E. O. Fischer and G. Besl, Z. Naturforsch., Teil B, 1980, 34, 1186. Novel carbene complexes of manganese obtained by reaction of cationic carbyne complexes with nucleophiles. 

Neither the palladium nor nickel catalyst described will promote the carbonylation of saturated aliphatic halides as noted above. However, this reaction can be catalyzed with cobalt (17) or iron (77) and probably with manganese (18) carbonyl anion salts. These carbonyl anions are strongly nucleophilic species and readily displace halide or other good leaving groups from primary or secondary positions giving alkyl metal carbonyl complexes. 

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