Revelation of the difference between arylzinc reagents prepared from aryl Grignard and aryllithium reagents respectively: kinetic and structural features
Related Experiment Video
Updated: Jun 18, 2026

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
Liqun Jin1, Chao Liu, Jing Liu
1College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, PR China.
Abstract:
Organozinc halide reagents are not as simple as RZnCl. Differences in solution NMR spectra and kinetic behavior of phenyzinc halide reagents prepared from Grignard (1a system) and lithium reagents (1b system), respectively, were observed. In the 1a system, zero-order kinetic behavior indicates that transmetalation is not the rate-limiting step, while first-order kinetics were observed in the 1b system, and the transmetalation step proved to be rate-limiting. The structure of 1a was revealed by single-crystal X-ray diffraction analysis to contain (THF)(4)MgCl(2) complexed to PhZnX. DFT calculations suggest weaker Ph-Zn bonds in 1a than in 1b, consistent with the faster transmetalation process in catalytic reactions.
More Related Videos
Related Concept Videos
Acid Halides to Alcohols: Grignard Reaction
Grignard reagents are a source of carbanions and function as nucleophiles. The mechanism begins with the nucleophilic attack by the carbanion at the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs,...
Acid Halides to Ketones: Gilman Reagent
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen double...
Nucleophilic Aromatic Substitution: Elimination–Addition
Nitriles to Ketones: Grignard Reaction
The mechanism begins with a nucleophilic attack by the Grignard reagent...
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Alcohols from Carbonyl Compounds: Grignard Reaction
Magnesium from the reagent coordinates with carbonyl oxygen, further reducing the carbonyl carbon's electron density. Thus, the carbonyl carbon is a...

