Hydride transfer

A reaction step in which hydrogen moves between species with both bonding electrons, formally as the hydride ion H⁻. It commonly transfers reducing equivalents in organic and biological chemistry.

Hydride shift: A rearrangement in which a hydrogen atom migrates with its bonding electron pair to a neighboring atom. This intramolecular form moves hydride between adjacent centers during a reaction.
Hydride ion: The anion H⁻, consisting of a hydrogen nucleus and two electrons. It is the formal transferred species that defines this reaction step.
Lithium aluminium hydride: A powerful inorganic reagent used to reduce many functional groups in organic synthesis. It delivers hydride equivalents to carbonyls, esters, and other electrophilic groups.
Hydrogenation: The addition of hydrogen to a molecule, often by catalytic reaction with H₂. Hydrogenation is a broader transformation that can proceed through hydride-transfer steps.
Nucleophilic addition: A reaction in which an electron-rich species forms a bond to an electron-poor center. Hydride adds to electrophilic carbonyl carbon in many reduction reactions.
Oxidation state: An atom’s formal charge after assigning bonding electrons to the more electronegative atom. Hydride transfer commonly changes the formal oxidation states of donor and acceptor.
Sodium borohydride: A boron-based reagent commonly used to reduce aldehydes and ketones. Its selective carbonyl reductions are a standard laboratory use of hydride transfer.
Redox reaction: A chemical reaction involving electron transfer or changes in oxidation state. Hydride transfer is a common two-electron pathway for redox transformations.
Transition state: A high-energy configuration at the maximum along a reaction pathway. Its geometry and energy reveal whether hydride moves directly or through a bridged arrangement.
Electrophile: An electron-pair acceptor that reacts with electron-rich species. Many hydride acceptors are electrophilic centers, especially polarized carbonyl carbons.

Linked from 7 pages

Lithium borohydrideRelated: LiBH₄ commonly reduces substrates by delivering hydride to electron-deficient atoms.