D-I
Dry ether
Write mechanism of
c=0+
+ R'-mg
1
Answers
Answer:
A Grignard reagent or Grignard compound is a chemical compound with the generic formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH
3 and phenylmagnesium bromide (C
6H
5)−Mg−Br. They are a subclass of the organomagnesium compounds
Usually Grignard reagents are written as RMgX, but in fact the magnesium(II) centre is tetrahedral when dissolved in Lewis basic solvents, as shown here for the bis-adduct of methylmagnesium chloride and THF.
Grignard compounds are popular reagents in organic synthesis for creating new carbon-carbon bonds. For example, when reacted with another halogenated compound R'−X' in the presence of a suitable catalyst, they typically yield R−R' and the magnesium halide MgXX' as a byproduct; and the latter is insoluble in the solvents normally used. In this aspect, they are similar to organolithium reagents.
Pure Grignard reagents are extremely reactive solids. They are normally handled as solutions in solvents such as diethyl ether or tetrahydrofuran; which are relatively stable as long as water is excluded. In such a medium, a Grignard reagent is invariably present as a complex with the magnesium atom connected to the two ether oxygens by coordination bonds.