metalallyl
Metal-allyl refers to organometallic compounds in which an allyl ligand, C3H5, is bound to a metal center. The most common binding mode is η3-allyl, in which the three contiguous carbon atoms of the allyl fragment interact with the metal through a π-allyl system; the ligand is formally described as an allyl anion (C3H5−) when bound to a low-valent, electron-rich metal, though neutral forms can be observed with more electron-deficient metals or different oxidation states. A related but less common mode is η1-allyl, where binding involves a single carbon atom.
Transition metals such as palladium, rhodium, nickel, cobalt, and iron form stable metal-allyl complexes. Common structural
Synthesis often proceeds by oxidative addition of allyl halides to low-valent, zero-valent metals or by deprotonation
Reactivity: Metal-allyl complexes are well known as key intermediates in catalytic allylation reactions, including the Tsuji–Trost
Applications: They are central to transition-metal catalysis in organic synthesis, enabling carbon–carbon bond formation and regio-