Related Experiment Video
Updated: Oct 3, 2026
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
The Reaction of LiAlH(4) with 1,4-Di-tert-butyl-1,4-diazabutadiene: Imine-Containing Aluminum Hydrides Stabilized by
Michael G. Gardiner1, Stacey M. Lawrence, Colin L. Raston
1School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia, Faculty of Science and Technology, Griffith University, Nathan, Brisbane, Queensland 4111, Australia, and Department of Chemistry, Monash University, Clayton, Melbourne, Victoria 3168, Australia.
Abstract:
The reaction of 1,4-di-tert-butyl-1,4-diazabutadiene, 1, with purified LiAlH(4) (free from Al metal) in diethyl ether has been investigated in detail, and a range of products have been isolated. The lithium diamidoaluminum dihydride [Li{N(t-Bu)CHCH(2)N-t-Bu}(2)AlH(2)], 2, the dimeric diamidoaluminum hydride [cis-{[&mgr;-N(t-Bu)CH(2)CH(2)N-t-Bu]AlH}(2)], 3, or the heteroleptic lithium tetraamidoaluminum species [(Et(2)O)Li{N(t-Bu)CH(2)}(2)(CHN-t-Bu)(2)Al], 4, can be selectively obtained depending on the order of addition or stoichiometry of the reactants. We have rationalized these results in terms of the unstable adducts which are likely to be present in solution at low temperature. The X-ray crystal structures of 2 and the dimeric lithium aluminum hydride adduct [{[HN(t-Bu)CH(t-Bu)CHN-t-Bu]Li(&mgr;-H)(2)AlH(2)}(2)], 7, are described.
Related Concept Videos
01:19Acid Halides to Alcohols: LiAlH4 Reduction
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
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.
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...
01:17Esters to Alcohols: Hydride Reductions
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
01:24Preparation of Aldehydes and Ketones from Nitriles and Carboxylic Acids
Reducing carboxylic acid derivatives like acyl chlorides (RCOCl), esters (RCO2R′), and nitriles (RCN) using milder aluminum hydride agents like lithium tri-tert-butoxyaluminum hydride [LiAlH(O-t-Bu)3] and diisobutylaluminum hydride [DIBAL-H] allows...
01:17Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene