Related Experiment Video
Updated: Aug 6, 2026
A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
Water, Alcohols, Amines, and Amides as Formal Hydrogen-Atom-Transfer Reagents Through Activation With Redox-Active
Petra Vojáčková1, Armido Studer1
1Organisch-Chemisches Institut, Universität Münster, Münster, Germany.
None:
The O─H and N─H bonds of protic molecules such as water, alcohols, amines, or amides typically resist hydrogen-atom abstraction because of the high energy of the resulting heteroatom-centered radical intermediates. However, association of the protic molecules with redox-active Lewis acids provides stabilization of the generated reactive radical intermediates and enables the ligated protic molecules to serve as hydrogen-atom donors or proton-coupled-electron-transfer reagents. This review presents an overview of applications of this bond-weakening principle in organic synthesis and attempts to illustrate the breadth of systems that enable such reactivity.
Related Concept Videos
00:55Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
01:17Carboxylic Acids to Primary Alcohols: Hydride Reduction
01:20Aldehydes and Ketones with Water: Hydrate Formation
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
01:20Amides to Amines: LiAlH4 Reduction
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
02:23Alcohols from Carbonyl Compounds: Reduction
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
02:15Preparation of Alcohols via Addition Reactions
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...