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Why do organometallic compounds of lithium and magnesium have carbanion character?

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periodic table with group numbers and the s, p, d, and f blocks — organometallic compound The periodic table of the elements, displaying the group numbers and the s, p, d, and f blocks. Elements in the shaded area are the metals of organometallic chemistry.

Organometallic compounds of lithium and magnesium exhibit carbanion character because they contain highly electropositive metals bonded to carbon atoms.12

In these compounds, the metal atom donates electrons to the carbon atom, resulting in a highly polarized metal-carbon bond. Because these metals are strongly electropositive, the electron density is shifted significantly toward the carbon, creating a partial negative charge on the carbon atom. This concentration of negative charge gives the organic group nucleophilic or carbanion character, making the compound behave as a strong base and a potent reducing agent.321

This reactivity is a fundamental feature of alkyllithium compounds and Grignard reagents (organomagnesium halides), which are widely utilized in synthetic organic chemistry to facilitate reactions such as the addition of organic groups to carbonyl compounds.14