Advices For Studying Organic Chemistry

Mg X

R

R

R

O

C 6 H 5

R O

1) Complex formation with molecules of ether is an important factor in the

formation and stability of Grignard reagents.

2) Organomagnesium compounds can be prepared in nonethereal solvents, but the

preparations are more difficult.

6. The mechanism for the formation of Grignard reagents might involve radicals:
   RX+ Mg R + MgX
   R + MgX RMgX

12.7 REACTIONS OF ORGANOLITHIUM AND

ORGANOMAGNESIUM COMPOUNDS

12.7A REACTIONS WITH COMPOUNDS CONTAINING

ACIDIC HYDROGEN ATOMS

1. Grignard reagents and organolithium compounds are very strong bases ⇒ they
   react with any compound that has a hydrogen attached to an electronegative atom
   such as oxygen, nitrogen, or sulfur.
   Rδ− δ+ Liδ+
   MgX and R

δ−

1) The reactions of Grignard reagents with water and alcohols are simply acid-base

reactions ⇒ the Grignard reagent behaves as if it contained an carbanion.

Rδ− MgXδ+ + H R H + H + Mg2+ + X −

Grignard reagent

(stronger base)

Water

(stronger acid)

Alkane

(weaker acid)

Hydroxide ion

(weaker base)

OH O −