Trimethylenemethane nucleophilic addition reaction

Nucleophilic attack on coordinated unsaturated hydrocarbons is one of the fundamental and particularly well studied reactions in Organometallic Chemistry. The addition of carbonylme-tallates instead of common nucleophiles provides a directed synthesis of hydrocarbon bridged complexes. Carbonylmetallates (particularly Re(CO)5", Os(CO)4 ") add to 7C-bonded olefin, acetylene, allyl, diene, trimethylenemethane, dienyl, benzene, triene and cycloheptatrienyl ligands in cationic complexes and give hydrocarbon bridged bi- and trimetallic, homo- or he-teronuclear complexes [1]. 

In another reaction of a trimethylenemethane complex, Sita et al. identified the unanticipated nucleophilic reactivity of the hgand in an electroneutral zir-conium(IV) complex 41. Nucleophihc addition of methyl, ethyl, or trimethylsilyl triflate, benzyl bromie, or trimethylsilyl chloride afforded adducts 42 in 50-98% yield (Scheme 10.15). The authors rationahzed the unexpected behavior on the basis of density functional theory (DFT) calculations [46]. 

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