472 CHAPTER 12 Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds
The Heck reactioncouples an aryl, benzyl, or vinyl halide or triflate (Section 12.4)
with an alkene in a basic solution.
The Stille reactioncouples an aryl, benzyl, or vinyl halide or triflate with a stannane.
Aryl and vinyl groups are coupled preferentially, but an alkyl group can be coupled if
a tetraalkylstannane is used.
The Suzuki reactioncouples an aryl, benzyl, or vinyl halide with an organoborane in
a basic solution.
PROBLEM 35
What alkyl halides would you utilize to synthesize the following compounds, using the
organoborane shown?
B
O
O
an organoborane
CH 2
Br
CH 2
CH 2 CH 2 CH 3
+ CH 3 CH 2 CH 2
+ + NaBr
B
O
O
HO B
O
O
+ HO B + NaBr
O
O
Pd(PPh 3 ) 4
CH 3 Br CH 3 CHCH 3
CH 3 CH CH NaOH
Pd(PPh 3 ) 4
NaOH
+ B
O
O
CH
Suzuki reaction
an aryl halide
an aryl triflate
Pd(PPh 3 ) 4
CCH 3
Br
CH 2 CH 2
(CH 3 CH 2 ) 3 N
Pd(PPh 3 ) 4
(CH 3 CH 2 ) 3 N
+ + HBr
+ HOTf
O
CCH 3
CH CH 2
O
CH 3 O
Heck reaction
OTf
+
CH 3 O
a stannane
CH (^3) THF (CH 3 CH 2 CH 2 CH 2 ) 3 SnBr
Stille reaction
CHSn(CH 2 CH 2 CH 2 CH 3 ) 3
Pd(PPh 3 ) 4
Br CH CH 2
- THF
Pd(PPh 3 ) 4
CH 2 CH 2 CH 2 CH 3
(CH 3 CH 2 CH 2 CH 2 ) 4 Sn
OTf
- THF
- (CH 3 CH 2 CH 2 CH 2 ) 3 SnOTf
tetrabutylstannane
John K. Stillewas a professor of
chemistry at Colorado State
University until his untimely death in
1989 in a commercial air crash on
his way to a scientific meeting in
Switzerland.
BRUI12-437_480r3 27-03-2003 11:51 AM Page 472
- (CH 3 CH 2 CH 2 CH 2 ) 3 SnOTf