For 10 points, identify this element, the lightest alkali metal with atomic number 3.
Complexes containing this metallic element are used to facilitate the ring closure of an R group in an ortho position to an aryl bromide in the Parham cyclization. The 12-crown-4 and 14-crown-4 ethers are highly selective for this element, and a class of reagents containing this element and dimethyl copper is named for Henry Gilman. The di-iso-propyl-amide salt of this element is commonly used as a strong base which lacks nucleophilicity, while a hydride containing it and aluminum is a strong reducing agent.  The carbonate salt of this element is used to tread depression. For 10 points, identify this element, the lightest alkali metal with atomic number 3.
Complexes containing this metallic element are used to facilitate the ring closure of an R group in an ortho position to an aryl bromide in the Parham cyclization.
{Lithium}