Grignard reaction

Abstract

A Grignard reagent is an organic magnesium halide. It can be either an alkyl or an aryl compound (RMgX or ArMgX). Grignard (pronounced green yard) reagents were first prepared in France around 1900 by Victor Grignard (1871-1935). Grignard reagents are usually made by reacting an organic halide and magnesium metal in an ether solvent: RX + Mg RMgX ether ArX + Mg ArMgX ether X = Cl, Br, or I X = Br In the Grignard reagent, the bonding electrons between carbon and magnesium are shifted away from the electropositive Mg to form a strongly polar covalent bond. As a result the charge distribution in the Grignard reagent is such that the organic group (R) is partially negative and the –MgX group is partially positive. This charge distribution directs the manner in which Grignard reacts with other compounds. – +