1. Chapter 15 Reagents with Carbon-Metal Bonds
Organometalic Synthesis of Alcohols

2. Section and Problem Assignments
SKIP: Section 15.6 and 15.9
In-Text Problems:
End of Chapter Problems:

3. Sect. 15.1: structure and properties of organometallic compounds
Organometallic compounds are prepared by the reaction of halides with metals such as sodium, lithium and magnesium.
These reactions involve reduction!!

4. Organolithium compounds

5. Formation of Organolithium Reagents
Examples
ether +2 +
butyllithium + +
phenyllithium

6. Organomagnesium compounds: Grignard Reagents

7. Victor Grignard Nobel Prize 1912
Source: Michigan State University, Department of Chemistry

8. SOLVENTS THAT ARE FREQUENTLY USED..
diethyl ether ..
Ethers work especially
well since they can
make complexes with
Grignard reagents
and solvate them.
THF
tetrahydrofuran .. ..
pentane ..
benzene .. .. .. .. ..
1,4-dioxane .. ..

9. Properties of organometallic compounds
polar covalent bond
partial negative charge on carbon
carbon is basic!
don’t memorize Table 15-1!

10. - BASES AND NUCLEOPHILES +
All of these reagents react as nucleophiles or bases: - +
Which are bonded, to various degrees, to the
accompanying metal.

11. Sect. 15.2: Reaction of Organometallic compounds with water and acid
Organolithium and organomagnesium compounds give alkanes when reacted with water and acid

12. CH3:- + H+ REACTIONS OF ORGANOLITHIUM COMPOUNDS - - + : d- d+
strong base
good nucleophile
57% covalent
43% ionic - +
ether + or
strong bases react with acids (even water and alcohols)
CH3: H+
strong
base
acid

13. - - - Any -O-H, -S-H, or -N-H bonds are sufficiently acidic to react.+ - - .. + .. - +
The reaction with H2O also means that you must rigorously
exclude water ( and water vapor = air ) from your reactions.

14. REMOVING A HALOGEN
The reaction with water is a way of reducing an alkyl halide
( converting C-X to C-H ).
ether Li
H2O

15. MAKING DEUTERIUM COMPOUNDS
ether + - .. +
Li+
Li+
ether Li
D2O
phenyllithium
This reaction of an alkyllithium compound with water is generally
not useful unless you use D2O, which is a way of placing a
deuterium atom in your compound.

16. Sect. 15.3: Reaction of Organometallic Reagents with epoxides
Grignard reagent
a terminal alcohol

17. Organolithium d- d+ d+ d-
Notice which carbon
got the nucleophile.

18. Sect. 15.4: Synthesis of Alcohols using Grignard reagents
ketone
tertiary
alcohol

19. THE CARBONYL GROUP .. : - + _ electrophiles attack here nucleophilic
at oxygen
H+ or E+ .. : d+ d- - + _
electrophilic
at carbon
Nu:
nucleophiles attack here

20. .. : .. - : : MgBr+ BrMg REACTIONS WITH THE CARBONYL (C=O) GROUP - d-
Since oxygen is more electronegative
than carbon, the carbonyl group is
electron-deficient at carbon, that is
an electrophile. : d+ .. - : :
MgBr+ - +
BrMg
new C-C
bond
The organometallic compound
(R-MgBr) behaves as a nucleophile
with an unshared pair on the
carbon.
NUCLEOPHILIC ADDITION TO CARBONYL

21. SYNTHESIS OF ALCOHOLS
Reaction of RMgBr with aldehydes and ketones yields alcohols
RMgX
formaldehyde
primary alcohol
RMgX
other aldehydes
secondary alcohol
RMgX
ketones
tertiary alcohol
The type of alcohol depends on whether you use formaledhyde,
another aldehyde, or a ketone.

22. SYNTHESIS PROBLEM
from

23. Sect. 15.5: Synthesis of Alkanes; the Wurtz reaction
2 R-X Na R-R NaX

24. Skip Section 15.6

25. Sect. 15.7: Preparation of lithium dialkyl cuprates

26. ALKYLATION WITH R2CuLi R-X + R2CuLi R-R + R-Cu + LiX
0o C
R-X R2CuLi
R-R R-Cu LiX
ether
X = Cl, Br, I
EXAMPLES
(CH3)2CuLi CH3(CH2)4-I
CH3-(CH2)4-CH3 +
Corey-House Reaction

27. MORE LITHIUM DIALKYLCUPRATE COUPLING
(CH3CH2)2CuLi +
CHBr3

28. Reaction of cuprates with acid chlorides
Cuprates react with acid chlorides
to give ketones

29. Sect. 15.8: Formation of organometallic reagents from alkynes
These reagents add to carbonyl groups!! Good stuff!!

30. Sect. 15.9: Organoboron Compounds revisited
Been there, done that!! See Chapter 14.