The syntheses and molecular structures of N-heterocyclic carbene-stabilized derivatives of BeCl2 ([L1:BeCl2] (1); L1: = :C{N(2, 6-iPr2C6H3)CH}2), [L1:BeCl2THF] (2), ([L2:BeCl2THF] (3); L2: = :C{N(2, 4, 6-Me3C6H2)CH}2, [L1:BeCl2]2dioxane (4)) and Be(BH4)2 ([L1:Be(BH4)2] (5)), are described herein. The reaction of lithium borohydride with 1 afforded carbene-stabilized beryllium borohydride, (5). Notably, compound 5 is the first structurally characterized compound containing the highly reactive Be(BH4)2 monomer. Structural analysis of 5 reveals a five-coordinate beryllium atom with distorted square pyramidal geometry. To probe the reactivity of 5, it was combined with a well-known reducing agent, disodium tetracarbonylferrate [Na2Fe(CO)4dioxane]. The addition of one equivalent of Na2Fe(CO)4dioxane to a toluene solution of 5 yielded a dually reduced compound containing a BH2 unit, (6). The BH2 fragment is stabilized by an N-heterocyclic carbene ligand and a reduced N-heterocyclic carbene moiety. The isolation of 6 represents the first example of the dual reduction of both the C=C carbene backbone (hydroboration) and the C2 carbene center (hydrogenation) of an N-heterocyclic carbene ligand. In comparison to carbene-complexed beryllium chlorides, the chemistry of electron-rich silicon compounds with beryllium chloride is also presented. The reaction of carbene-stabilized disilicon, L1:Si=Si:L1 [L1: = :C{N(2, 6-iPr2C6H3)CH}2], with BeCl2 in hexane quantitatively yields [L1:Si=Si:L1]BeCl2, (7). Remarkably, compound 7 is the first example of a molecule containing a siliconberyllium dative bond. The X-ray structure of 7 reveals that one silicon atom in [L1:Si=Si:L1] serves as a monodentate two-electron donor ligand for beryllium chloride, while the other silicon atom has a non-bonding electron pair. In notable contrast to carbene ligand systems, the reactivity of BeCl2 with diimine ligands is also explored. Sterically demanding diimines ([L3 = {:N(2,6-iPr2C6H3)CH}2] and [L4 = {:N(2, 4,6-Me3C6H2)CH}2] were used to prepare the corresponding beryllium chloride complexes, [L3BeCl2 (8) and L4BeCl2 (9)]. Reduction of 9 with potassium graphite yields a diimine-stabilized beryllium dimer containing a Be2N2 four-membered ring, [L4Be]2 (10).