The formation of ester-stabilized organozinc reagents and their addition to carbonyl compounds
Mechanism of the Reformatsky Reaction
Organozinc compounds are prepared from α-halogenesters in the same manner as Grignard Reagents. This reaction is possible due to the stability of esters against organozincs. Due to the very low basicity of zinc enolates, there is hardly any competition from proton transfer, and the scope of carbonyl addition partners is quite broad. In presence of ketones or aldehydes, the organozinc compounds react as the nucleophilic partner in an addition to give β-hydroxy esters.
An ester-stabilized organozinc reagent
Compared to organolithiums and organomagnesium halides (Grignard reagents), the organozinc halide reagents used in the Reformatsky Reaction are relatively stable, and many are available commercially.
An operationally simple and very efficient Reformatsky reaction of aldehydes has been carried out in THF in the presence of low valent iron or copper which were prepared in situ employing a bimetal redox strategy through reduction of Fe(III) or Cu(II) salts with magnesium.
A. Chattopadhyay, A. Kr. Dubey, J. Org. Chem., 2007, 72, 9357-9359.
In- or In(I)-Employed Tailoring of the Stereogenic Centers in the Reformatsky-Type Reactions of Simple Ketones, α-Alkoxy Ketones, and β-Keto Esters
S. A. Babu, M. Yasusa, I. Shibata, A. Baba, J. Org. Chem., 2005, 70, 10408-10419.
Efficient Synthesis of 2-Amino Acid by Homologation of β2-Amino Acids Involving the Reformatsky Reaction and Mannich-Type Imminium Electrophile
R. Moumne, S. Lavielle, P. Karoyan, J. Org. Chem., 2006, 71, 3332-3334.
High Chelation Control of Three Contiguous Stereogenic Centers in the Reformatsky Reactions of Indium Enolates with α-Hydroxy Ketones: Unexpected Stereochemistry of Lactone Formation
S. A. Babu, M. Yasuda, Y. Okabe, I. Shibata, A. Baba, Org. Lett., 2006, 8, 3029-3032.