Reformatsky and Luche Reactions

Reformatsky and Luche reactions with Zn provide more economical C-C bond formation methods than Grignard reactions, which use more expensive Mg metal. Both the reactions proceed efficiently in the absence of solvent [10], These nonsolvent reactions can be carried out by a very simple procedure and give products in higher yield than with solvent. 

In general, the solvent-free reactions were carried out by mixing aldehyde or ketone, organic bromo compound, and Zn-NH4C1 using an agate mortar and pestle and by keeping the mixture at room temperature for several hours. 

Treatment of the aromatic aldehydes (21a-e) with ethyl bromoacetate (22) and Zn-NHaCl gave the corresponding Reformatsky reaction products 23a-e in the yields shown in Table 15-6. The yield, for example, of 23a obtained in the solvent-free reaction (91%) is much higher than that obtained by the reaction in dry benzene-ether solution (61-64%) [11, 12]. The nonsolvent Reformatsky reaction, which does not require the use of an anhydrous solvent, is thus advantageous. 

Aldehyde or ketone Reaction time (h) Product Yield (%) 

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