Iron Catalyzed Cross-Coupling Reaction: Recent Advances and Primary Mechanism Wang Chao 2010.11.6
Jan 07, 2016
Iron Catalyzed Cross-Coupling Reaction:Recent Advances and Primary Mechanism
Wang Chao2010.11.6
General:
CheapEnviromentally benignSustainableUnique reactivity
Genesis:
Kochi: J. Am. Chem. Soc. 1971, 93, 1487
BrMeMgBr
Br
FeCl3 Cat. FeCl3 Cat.
MgBr + BrFeCl3 (5 mol%)
0.106 mol 0.1 mol 47% yield
Kharasch: J. Am. Chem. Soc. 1941, 63, 2316
R1C(O)X + R2M[Fe] (cat)
R1 R2
O
Ph
O
Me
Me
n-C7H15
O
OPiv
Ph
O
Cl
89% yield(X = SPh)
(M = MgBr)
89% yield(X = Cl)
(M = ZnR2)
79% yield(X = CN)
(M = MgCl)
O
OOAc
O
n-C6H13
O
MeMe78% yield(X = Cl)
(M = MgBrl)
90% yield(X = Cl)
(M = MgBrl)
NPMBS
OCl
[Fe(acac)3](1.5 mol%)
MeMgBr, THF-78 to 0oC80% yield
O
NPMBS
OMe
O
Latrunculin A
Acid chlorides as electrophiles
R3
R2
R1
X + R4MgBr[Fe] (cat)
R3
R2
R1
R4
Men-Bu
O
( )3 Me
O
O n-Bu
n-C10H21
OMe
N
n-C14H29
Boc
Ph
O
O
80% yield(X = Cl)
70% yield(X = OTf)
78% yield(X = OP(O)(OEt)2)
66% yield(X = SPh)
73% yield(X = OTf)
68% yield(X = OTf)
Me
HTfO HMe
Me
Me
HMe HMe
Me
Fe(acac)3 (10 mol%)
MeMgBr, THF/NMP, -30oC90% yield
Alkenyl electrophiles
(-)-cubebene (5)
OTf
TfO
catalyst
BnMgCl, THF
Bn
Bn
PhPh
9 10+
菲尔斯特纳 Furstner: Angew. Chem., Int. Ed. 2002, 41, 609
CO2Me
X11
Fe(acac)3 (5 mol%)n-C6H13MgBr
THF/NMP0oC to rt, 5 min
CO2Me
R12
Aryl electrophiles:
N n-C6H13
90% yield, cat Fe(acac)3
88% yield, cat FeCl3
96% yield, cat Fe(salen)Cl
MeO2C
n-C6H13
NC
n-C6H13
91% yield, X = Cl
87% yield, X = OTf
83% yield, X = OTs
91% yield, X = Cl
80% yield, X = OTf
74% yield, X = OTs
n-C14H29
OMe
MeO
0% yield, X = Cl
90% yield, X = OTf
0% yield, X = OTs
n-C14H29
O
81% yield, X = OTf
N
N
n-C6H13
93% yield, X = Cl
allyl, vinyl, and aryl Grignard reagents uniformly led to poor yields in reactions performed with FeX3 (X =Cl, acac) in THF/NMP
CO2Me
Cl11
Fe(acac)3 (cat)n-C9H19MgBr
THF/NMP0oC to rt
CO2Me
R13
7 min, 16 g scale79-84% yield
NCl Cl
OBnBrMg( )6
Fe(acac)3 (cat)THF/NMP
0oC, 83% yield
OBn( )6NCl
NNH
H
NH
O
isooncinotine
a valuable component of liquid-crystalline materials
spermidine alkaloid
Masaharu Nakamura: J. AM. CHEM. SOC. 2007, 129, 9844-9845
ClFeX3 (5 mol%)
p-TolMgBrTHF, 60oC
+
Me
21
22
+
23
Me
24 Me
Alkyl halides
Nakamura, Eiichi: J. AM. CHEM. SOC. 2004, 126, 3686-3687
BrFeCl3 (5 mol%)
PhMgBr (1.2 equiv)additive (1.2 equiv)
THF-78oC to 0oC (30 min)
Ph
+ +1 2 3 4
the high barrier to oxidative addition -hydride elimination
Hayashi: Org. Lett. 2004, 6, 1297–1299.
p-TolMgBr (1a)(2.00 mmol)
Ph(CH2)5Br (2m)(1.00 mmol)
+Fe(acac)3 (5 mol%)
solvent, 20oC, 0.5h
(CH2)5Ph
PhPh
3am
4 5 6
(CH2)3Br
OTf
p-TolMgBrFe(acac)3 (5 mol %)
Et2O, reflux, 0.5 h69% TfO
n-C4H9MgBrFe(acac)3 (5 mol %)
THF/NMP, 20oC, 0.5h
90%
Angew. Chem. Int. Ed. 2004, 43, 3955 –3957
L = TMEDA
RX + PhMgBr
[Fe(C2H4)4][Li(tmeda)]25 mol%
THF, -20oCR Ar
PhPhNC
( )6PhOCN
( )3
PhCl( )4
Ph
Et
O
EtO EtO
O
Ph
Me Ph
Me Me
Ph( )3
O
Ph
94% yield(X = Br)
83% yield(X = I)
90% yield(X = I)
86% yield(X = I)
94% yield(X = Br)87% yield
(X = Br)
87% yield(X = Cl)
91% yield(X = I)
PhN
O
87% yield(X = I)
[FeCl (salen)]
Cahiez: Angew. Chem. Int. Ed. 2007, 46, 4364 –4366
Bedford: Chem. Commun.2004, 2822–2823.
N N
O OFe
Cl
Me Et
Br[(FeCl3)2(tmeda)3]
(1.5 mol%)
PhMgBr (1.3 equiv)20oC, THF, 90 min
78% yield, 0.1 mol scale
Me Et
Ph
Bedford: J. Org. Chem. 2006, 71, 1104-1110
Iron-Phosphine, -Phosphite, -Arsine, and -Carbene Catalysts
PPh3
PCy3
AsPh3
P(OPh)3
P(OMe)3
Ph2P PPh2
Ph2PPPh2
Ph2P PPh2
Ph2P
PPh2
Ph2P PPh2
Ph2As AsPh2
Pt-Bu
t-BuP
Cy
Cy
Ph2P PPh2
N NCy Cy
Cl-
N Nt-Bu t-Bu
Cl-N NMes Mes
Cl- N NMes Mes
H C6H5
Kochi, J. J. Org. Chem. 1976, 41, 502
Fe(iii)RMgBr
Fe(i)
Mechanism for the cross coupling:
FeI
FeIIIR
CH=CHCH3FeIII
Br
CH=CHCH3
Br
RMgBrMgBr2
R
FeX3
Fe(MgX)2
R1-Fe(MgX)
R1-Fe(MgX)2
R2
R2MgX
R1-X
MgX2
R1-R2
RMgX
Bogdanovic:
four-electron reduction, formal constitution [Fe(MgCl)2]n1:1 mixture of alkene and alkane is formed from the Grignard reagent in the reduction of FeX2, Bogdanovic proposed a -hydride elimination followed by a reductive elimination as two of the elementary steps
1:1 mixture of alkene and alkane is formed from the Grignard reagent in the reduction of FeX2, Bogdanovic proposed a -hydride elimination followed by a reductive elimination as two of the elementary steps in the formation of [Fe(MgX)2]
COOMe
Cl
MeMgBr
Fe(acac)3(5 mol%)
Fe(acac)3(5 mol%)
EtMgBr
no cross coupling
COOMe
>95% yield
J. AM. CHEM. SOC. 2008, 130, 8773–8787Ferrate: 高铁酸盐
Masaharu Nakamura: Hideo Nagashima: J. AM. CHEM. SOC. 2009, 131, 6078–6079
FeCl3
mesityl-MgBrTMEDA N N
Femesityl mesityl
N NFe
Br mesityl
1 2
1-bromooctane octyl-mesitylene
mesityl-MgBrMgBr2
Br
Br
0.06 mmol
+ N NFe
mesityl mesityl
0.05 mmol
THF, 30oC18h
Br+
hexenyl
+
25%63% 0%
+ N NFe
mesityl mesityl
0.10 mmol
THF, 30oC18h0.20 mmol
+
butenyl
17% 55%
Radical cyclization rate 1.0x105M-1S-1
Radical ring open rate 1.3x108M-1S-1
Possible catalytic cycle for the (TMEDA)FeAr2-catalyzed crosscoupling reaction.
Masaharu Nakamura: J. AM. CHEM. SOC. 2010, 132, 10674–10676
features: (1) divalent iron (+II oxidation state),(2) neutral complex, (3) coordinatively unsaturated,(4) having sufficient spin density on the iron center.
Ar BO
OB
O
OR
ArLi+a b, c
(a) RLi, THF, -78 to 0 oC, 1h, (b) R'X(c) cat. 1 or 2, 20 mol% of MgBr2, THF, 0 to 40oC
Cl + BO
OBu
PhLi+
catalystadditive
THF25oC, 4h
Ph
c-Hept
99% yieldX = Br
c-Hept
77% yieldX = Br
Cl c-Hept
90% yieldX = Br
CO2Mec-Hept
98% yieldX = Br
OMe
EtO Ph
O
( )5
90% yieldX = Br
NC( )5
90% yieldX = Br
NMe
Ph Ph
O
( )4
65% yieldX = Br
N
Cl CO2i-Pr
86% yieldX = Cl
Shi, ZJ: J. AM. CHEM. SOC. 2009, 131, 14656–14657
OPiv
CO2Et
+ n-hexylMgX
1a 2
[Fe] (1.0 mol%)ligand (2.0 mol%)
THF, 0oC, 1h
nhexyl
CO2Et
3a
N N
N NCl-
H2IMes HCl
Me2N NMe2
bipy tmeda
Oxidative homo-coupling
Cahiez: J. AM. CHEM. SOC. 2007, 129, 13788-13789
MgBrMeO
THF, rt
conditionsMeO OMe
Dry air: 5%5% FeCl3: 13%
5% FeCl3, dry air: 88%
MeO OMe
88% yield
85% yield72% yield
EtO2C CO2Et
70% yield at -20oC X=Cl
NC CN
MeO
OMe
Bu
BuBu
Bu
60% yield
Ph
Ph
E/E, E/Z, Z/Z = 92:6:268% yield
72% yield at -20oC X=Cl
RMgX
Dry air5% FeCl3
THF, rt, 45minR R
Angew. Chem. Int. Ed. 2009, 48, 2969 –2972
Zn +Br
Fe(acac)3 (5 mol %)TMEDA (1.5 equiv)
THF, 50oC, 30 min
+
81% 11%
Zn
Fe(acac)3 (15 mol %)BrCH2CH2Br (1 equiv)
THF, 50oC, 30 min58%
Zn)2 + iPr2Zn
Fe(acac)3 (15 mol %)BrCH2CH2Br (1 equiv)
THF, 50oC, 30 min96%
Only one Ph group and one iPr group are transfered
ZnMe + iPr2Zn
Fe(acac)3 (10 mol %)BrCH2CH2Br (1 equiv)
THF, rt, 3h79%
ZnMe +Fe(acac)3 (10 mol %)BrCH2CH2Br (1 equiv)
THF, rt, 3hRR2Zn
benzyl-, allyl-, or tertiary alkylzinc give low yields
J. AM. CHEM. SOC. 2008, 130, 5858–5859
N
PhMgBr (6 equiv)ZnCl2 TMEDA (3 equiv)
Fe(acac)3 (10 mol%)1,10-phenanthroline (10 mol%)
ClCl (2 equiv)
THF, 0oC, 16h
N
Ph
99%
N
H
FeCl3 (x mol%)L (x mol%)ZnCl2 TMEDA (y equiv)PhMgBr (2y equiv)
oxidant (z equiv)THF, 0oC
N
Ph
N
Ph
+Ph
L =bpy, oxidant = DCE, x=15, y=4, z=3, 72h 53% 2%
L =bpy, oxidant = DCIB, x=15, y=4, z=3, 24h 82% 9%
L =phen, oxidant = DCIB, x=10, y=3, z=2, 24h 79% 16%
N NN N
ClCl
ClCl
bpy phen DCE DCIB
Cross-coupling based on C-H activation/C-C bond formation:
Cheap iron and mild condition 0oC
Angew. Chem. Int. Ed. 2009, 48, 2925 –2928
X
HN Ar
Ar = 4-MeOC6H4X = Br, Cl, TfO, TsO etc.
+
MgBr
(5-6 equiv)
+ZnCl2 TMEDA(2.5-3 equiv)
[Fe(acac)3] (10 mol%)dtbpy (10 mol%)
ClCl (2 equiv)
THF, 0oC
H+ XO
83-92% yield
R
OPhOPh OPh
OPh
R
OPh
S
96%87% (R = Cl)88% (R = Br)
91% (R = H)92% (R = Cl)83% (R = Br)89% (R = OTf)89% (R = OTs)94% (R = OMe)90% (R = CF3)57% (R = CN)
99%(3%
J. AM. CHEM. SOC. 2010, 132, 5568–5569
O
solvent
cat. Fe(acac)3/dtbpy2 PhMgBr/ZnCl2 TMEDA4-Iodotoluene
O Ph
dtbpy = 4,4'-di-t-butyl- 2,2'-bipyridyl
NCH2
I
1
RMgBr or 2 RMgBr/ZnCl2 TMEDAFe(acac)3 (2.5-5 mol%)
t-BuOMe, Et2O or THFrt or 50oC, 15-30 min
N I
1
HR
NCH2
R[Fe]I
NC
R[Fe]IH
H NC
H
H[Fe] I
R
A B C
R[Fe] -[Fe]I
N
O
I
N IN IO
N N I
I
Substrates with unsuitable type of internal trigger of C-H bond
N
IBn
D DDD
N
IBn
+ArMgBr (2 equiv)Fe(acac)3 (5 mol%)
t-BuOMe, 50oC(Ar = p-FC6H4)
NDD
N+
HAr
DArD
N
IBn
D DDD +
N
IBn
H HHH
NDD +
DArD NH
H
HArH
ArMgBr (0.5 mmol)Fe(acac)3 (2.5 mol%)
t-BuOMe, rt, 5min(Ar = p-FC6H4)
0.5 equiv 0.5 equiv
(IBn = 2-Iodobenzyl)
(IBn = 2-Iodobenzyl)
0.25 mmol 0.25 mmol
0.12 mmol 0.12 mmol
NBn
NBn N
Bn
NBn
Ph
NBn N
BnNBn
NBn
NBn
NBn
PhPh
Ph84% 82% 82%
67% 8%
X
n-C6H13
47%69%70%
91% (X = H)88% (X = Cl)90% (X = OMe) N
88% 54%
NBn
BuPh+
Yu, XQ: Angew. Chem. Int. Ed. 2008, 47, 8897 –8900
NH
NH
HN
HN
1,4,7,10-tetraazacyclododecane
+Br
(HO)2B
[Fe], base
solvent, 135oCBr
Lei AW: Angew. Chem. Int. Ed. 2010, 49, 2004 –2008
BrMeO H+
FeCl3DMEDA
MeO80oC
48hoursbase
MeHN NHMe
Charette: J. AM. CHEM. SOC. 2010, 132, 1514–1516
I H+R R
Fe(OAc)2 (5 mol%)bathophenanthroline (10 mol%)
KOt-Bu (2 equiv)
80 oC, 20h