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Iridium Catalyst System for Transfer Hydrogenation. Wu Hua 2012-6-9. Iridium Hydride Complex Catalyzed Addition of Nitriles to Carbon-Nitrogen Triple Bonds of Nitriles. - PowerPoint PPT Presentation
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Iridium Catalyst System for Transfer Hydrogenation
Wu Hua
2012-6-9
Shun-Ichi Murahashi. J. Am. Chem. Soc. 1998, 120, 4244-4245
Iridium Hydride Complex Catalyzed Addition of Nitriles to Carbon-Nitrogen Triple Bonds of Nitriles
R1 C
H
H
CN IrLnR1 C
H
IrLnH
CN
NC-R2
R1 C
H
IrLnH
CNNC-R2
Ln = PR3, CO, H
R1 C
H
C
CN
NIrLnH
R2-IrLn
R1 C
H
C
CN
NH
R2 C CNH2
R2
R1
CN
R1CH2CN + C NR2 Ir cat.
NH2
R2NC
R1
A mixture of nucleophile (1.0 mmol), nitrile (2.0 mmol), and IrH(CO)(PPh3)3 (3 mol %) in dry THF (0.25 mL) was stirred at 120 °C for 12 h under argon.
Mechanism:
Yasutaka Ishii. Angew. Chem. Int. Ed. 2001, 40, 2534-2536
A Three-Component Coupling Reaction of Aldehydes, Amines, and Alkynes
H
R2
NR1
IrILn NR1R1
NR1R1
IrILnH
NR1R1
IrIIILnHR2
NR1R1
IrIIILnH
IrIIILn
R2
NR1 H
R2
n-Pr
O
H+ n-Pr NH2 + n-Hex
cat.[{Ir(cod)Cl}2]
THF, 60 oC
n-Hex
N n-Prn-Pr
Ken-ichi Fujita, Ryohei Yamaguchi. Tetrahedron Letters. 2003, 44, 2687–2690
N-Alkylation of amines with alcohols catalyzed by a Cp*Ir complex
NH2
NH2
NH2
NH2
MeO
Cl
OH
OH
OH
OH
Yield
85
92
93
95
R1
NH2
+R2 R3
OH[Cp*IrCl2]25.0 mol%K2CO35.0 mol%
Toulene110 oC, 17 h
R1
N
R2
R3H
Substrates:
Mechanism:
[Cp*IrCl2]2
R2
OH
R3+ K2CO3
O
R2
R3
[Cp*Ir]
R2
O
R3
R1NH2
H2O
[Ir*Cp] H
N
R2
R3R1N
R2
R3
R1
[Cp*Ir]
R2
OH
R3
R2
NHR1
R3
The base (K2CO3) wouldstimulate the first oxidation step
Kazuhiko Taguchi, Yasutaka Ishii. J. Am. Chem. Soc. 2004, 126, 72-73
An Efficient Direct r-Alkylation of Ketones with Primary Alcohols Catalyzed by [Ir(cod)Cl]
2/PPh3/KOH System without Solvent
Kazuhiko Taguchi, Yasutaka Ishii. J. Am. Chem. Soc. 2004, 126, 72-73
i) R1CH2OH[Ir(cod)Cl]2 R1CHO + LnIr
H
H
ii) R1CHO + R2
O base
R1 R2
O+ H2O
iii) R1 R2
O LnIrH
H
R1 R2
O
Kazuhiko Taguchi, Yasutaka Ishii. J. Am. Chem. Soc. 2004, 126, 72-73
Mechanism:
Tomoya Mizuta, Satoshi Sakaguchi, and Yasutaka Ishii. J. Org. Chem. 2005, 70, 2195-2199
Catalytic Reductive Alkylation of Secondary Amine with Aldehyde and Silane by an Iridium Compound
Tomoya Mizuta, Satoshi Sakaguchi, and Yasutaka Ishii. J. Org. Chem. 2005, 70, 2195-2199
IrLn
Et3SiD
Et3Si-Ir-DLn
Et3SiOH
H2O
H-Ir-D
Ln
N
R'
R R
H
R'
Ir
NR R
D Ln
D
R'
Ir
NR R
H Ln
H
R'
D
NR R
D
R'
D
NR R
+
+
Plausible Mechanism:
Guerbet Reaction of Primary Alcohols
Yasutaka Ishii. J. Org. Chem. 2006, 71, 8306-8308
10 mol% 1,7-octadiene
ROH2
1 mol% [Cp*IrCl2]2
40 mol% t-BuOK
p-xylene 0.5 mL
R
OHR
ROH
dehydrogenation
- 2H22 R
O
H
+ ROH
H
RO
OHR
HB:
-H2OR
OR hydrogenation
+ 2H2 ROH
R
Guerbet alcohols
Mechanism of Guerbet reaction:
Yasutaka Ishii. Org. Lett. 2006, 8, 2459-2462
New Coupling Reaction of Secondary Amines, Aldehydes, and Alkynes Catalyzed by an Iridium Complex
R1 NH
R1 +R2 H
O+ R3
[IrCl(cod)]2
1,4-dioxane50oC, 3h
R3 = R4CH2
R1 N R1 R1 N R1
+R2
R4 R4
R2
Mechanism:
R1 N R1
IrH2
R1 NH
R1
R1 N R1
R3
R2
R1 N R1
R2
R4 (R3 = R4CH2)
R1 NH
R1 + R3
Ir
R1 N R1
R3
R1 N R1
R3
Ir-H
R2
O
HR1 N R1
R3
R2
OIr
Ir
- H2O
The reaction is initiated!
Yasutaka Ishii. Tetrahedron Lett. 2006, 47, 9199–9201
Oxidative dimerization of primary alcohols to esters catalyzed by iridium complexes
R OH
[IrCl(coe)2]2 (3mol%)
95oC, 15h
open air
R O R
O
R OH
R H
O
R OH
R O
OH
R
R O
O
R
LnIr
LnIrH2
LnIr
1/2 O2
H2O
Yasutaka Ishii. Chem. Commun. 2007, 2850–2852
Alkylation of active methylene compounds with alcohols catalyzed by an iridium complex
NC
O
On-Bu+ OH
CN
O
On-Bu5 mol% [IrCl(cod)]2, 20 mol% PPh3
p-xylene, 130oC, 15h
R2 OH LnIr LnIrH2R2 O+ +
O
NCR1
+ R2 OLnIrH2
R2
CN
O
R1 + LnIr + H2O
a)
b)
Mechanism:
Yasutaka Ishii. Bull. Chem. Soc. Jpn. 2008, 81, 689–696
Synthesis of Diketones and ω -Hydroxy Ketones from Methyl Ketones and , α,ω –Diols by an [IrCl(cod)]2/PPh3/KOH System
R
O+
HO OHn
5 mol% [IrCl(cod)]2
PPh310 mol%
10 mol% KOH
without solvent100oC, 15h
R
O O
Rn
Iridium-Catalyzed α-Alkylation of Acetates with Primary Alcohols and Diols
O
OBu-t + ROH
[IrCl(cod)]2/PPh3
tert-BuOK, tert-BuOH
100oC, 15h
O
OBu-tR
Yasutaka Ishii. J. Am. Chem. Soc. 2010, 132, 2536–2537
Yasutaka Ishii. J. Org. Chem. 2009, 74, 628–633
N-Heterocyclization of Naphthylamines with 1,2- and 1,3-Diols Catalyzed by an Iridium Chloride/BINAP System
NH2
+ HO OH
IrCl3.3H2O (5mol%)
BINAP (7.5mol%)Na2CO3 (8mol%)
Mesitylene (3 mL)reflux (169oC)
under Air, 15h
N
Yasutaka Ishii. J. Org. Chem. 2009, 74, 628–633
HN N
IrLn
NH
NH IrLn
NH
LnIr LnIrHN
H2O O2
HO OH
LnIr [LnIrH]
HO H
O
NH2
HNLnIr[LnIrH]
H2O
OH
N OH
LnIr [LnIrH] HN H
ONH2
H2O
HN N
R OH + Ar Me
[Ir(OH)(cod)]2
P(n-Otc)3
Toluene100oC 15h,
R
OH
Ar
Yasutaka Ishii. Org. Lett., 2009, 11, 3510-3513
Iridium-Catalyzed Coupling Reaction of Primary Alcohols with 1-Aryl-1-propynesLeading to Secondary Homoallylic Alcohols
Yasutaka Ishii. Org. Lett., 2009, 11, 3510-3513
Iridium-Catalyzed Coupling Reaction of Primary Alcohols with 1-Aryl-1-propynesLeading to Secondary Homoallylic Alcohols
Yasutaka Ishii. Chem. Eur. J. 2010, 16, 1883 – 1888
"LnIr" "LnIrH2"
R
OH
Ar
R
O
Ar
IrHLn
R
O
H
Ir O
R
H
H
ArH
Ln
HH
Ar H
H
Ir
H
Ln
Ir CH3
HAr
HLn
A Plausible Reaction Mechanism:
Yasutaka Ishii. Angew. Chem. Int. Ed. 2011, 50, 8618 –8622
Iridium-Catalyzed Reactions of w-Arylalkanols to α,ω –Diarylalkanes Diarylalkanes
OH
R
route A [(Cp*IrCl2)2]
p-xylene
120oC, 4h
n=1
R
n n n
[(Cp*IrCl2)2]
t-BuOK1,4-dioxane120oC, 24h
n=2-5
(Step 1)
route B
R
n-1
HO
n-1R
[(Cp*IrCl2)2]
[{IrCl(cod)}2]/dppe
k2CO3
Mesitylene
160oC, 24h
(Step 2)
R
Yasutaka Ishii. Angew. Chem. Int. Ed. 2011, 50, 8618 –8622
O
H
O Hbase H2O
OH
OH
2LnIrH2
2LnIr
O HLnIrH2
LnIr
2
2
LnIr
oxidative addition
decarbonylation
H-elimination
Step 1
Step 2
Summary
a. Reaction Temperature
b. Rh, Ru, Ni
c. Development of hydrogen transfer reactions