In many of the following reactions, organozinc compounds participate in the reaction as intermediates:
1. Simons – In the Smith reaction, carbene (iodomethyl) zinc iodide reacts with an alkene to give cyclopropane.
2. In the Frankland-Duppa reaction discovered in 1863, oxalate ester (ROCOCOOR) reacts with haloalkane R’X, zinc and hydrochloric acid to generate α-hydroxycarboxylate RR’COHCOOR[8 ]
3. Reaction of zinc salt of acetylides.
4. Organozinc reagent addition reaction to carbonyl group. The Barbier reaction discovered in 1899 uses zinc instead of magnesium for the Grignard addition reaction, and the reaction is milder; the reaction conditions are simpler. When an organomagnesium halide reagent is used for an addition reaction, the presence of any water will prevent the reaction from proceeding; however, the Babier reaction can even proceed in the presence of water. The disadvantage of Organozinc reagent is that it is less nucleophilic than Grignard reagent. Of all the Group 12 elements, zinc is the most reactive. Commercially available dialkyl zinc compounds include dimethyl zinc, diethyl zinc and diphenyl zinc. These reagents are expensive and difficult to operate and control. In a study,[9][10] active organozinc compounds can be obtained through cheaper organobromine compound (Organobromine) precursors:
5. Refolmatsky reaction through zinc halogen The intermediate converts α-halogenated ester and aldehyde to obtain β-hydroxyester.
Organozinc compounds refer to a class of organic compounds containing carbon-zinc chemical bonds. Organozinc chemistry is a discipline that studies the physical and chemical properties, synthesis and reactions of organozinc compounds. [1][2][3][4] The first organozinc compound discovered and prepared was diethylzinc (discovered by Edward Frankland in 1849). It was also the first compound discovered to have a metal-carbon σ bond. Many organozinc compounds are flammable and difficult to handle (most organic solvents are also flammable and present a safety hazard). Most organic zinc compounds are easily oxidized and will decompose when dissolved in protic solvents. In many reactions, organozinc reagents need to be prepared and used immediately and cannot be separated, purified or stored for too long. All reactions using organozinc reagents need to be carried out under the protection of an inert gas, such as nitrogen or argon. The most common oxidation state of organozinc compounds is +2. It can be divided into three types: organic zinc halogen compounds (R-Zn-X, where X represents a halogen atom); dialkyl zinc compounds (R-Zn-R, where R represents an alkyl or aryl group); zincic acid Lithium salt or magnesium zincate salt (M+R3Zn-, where M represents lithium or magnesium). Due to the different electronegativities of the carbon and zinc elements: (2.55 for carbon; 1.65 for zinc), the polarity of the carbon-zinc chemical bond points toward the carbon atom. Dihydrocarbyl zinc compounds usually exist in monomer form, while organozinc halogen compounds can form polymeric forms through halogen bond bridges, which are similar to Grignard reagents and Schlenk equilibrium of Grignard reagents.
